Scent and Decorative Herbs

Source(s): Wayne McLaurin, Professor Emeritus of Horticulture, The University of Georgia, College of Agricultural and Environmental Sciences


Herbs that can be grown in the South provide numerous ways to decorate and scent homes, yards, and places of business. Some of the following herbs are also edible.

herb

Anise Hyssop (Agastache foeniculum)

A tall perennial with small purple flowers, anise hyssop (neither true anise nor hyssop) blooms in the South throughout the summer. An excellent bee plant, it grows best in a sunny area and may be propagated through seed or root division.

Artemisia (Artemisia abrotanum – Southernwood; Artemisia absinthium – Wormwood)

Artemisias are noted for their grey-green or silver foliage, either ferny or slightly cut leaves. Of the numerous species, southernwood and wormwood are most popularly grown in the Southern herb garden. Artemisias favor full sun, tolerate light shade and soil with some clay. As perennials, artemisias grow woody and leggy. They should be trimmed back in spring and divided every two to three years. Strong-scented artemisias are said to be useful for repelling moths and fleas. They are particularly decorative in the garden as a contrast plant among colors and greens of other plants.

Comfrey (Symphytum officinale)

Though once used as a wound dressing, comfrey in today’s herb garden or landscape is a striking, expansive plant with large leaves and pink flowers sent up on stalks in early summer. It is a perennial that reappears each spring. The plant should be watched for slug infestations. A light mulch will keep its leaves off the ground and create a less desirable habitat for pests. It is propagated primarily by division or root cuttings.
Costmary (Chrysanthemum balsamita). A midsummer bloomer with small yellow flowers, costmary produces large, oblong, fragrant leaves which tend to look scraggly as the season progresses. It is a hardy perennial and is related to

Chrysanthemum parthenium, daisy-like feverfew.

It will spread, though not invasively, through underground rhizomes and should be divided after two or three years.

Hyssop (Hyssopus officinalis)

An attractive perennial border plant with small, dark green leaves, hyssop bears pink, white, or blue flowers in the spring. Hyssop prefers a sandy soil or at least very well-drained soil and plenty of sun. It is propagated through division, cuttings, or seed. The spicy scent of both its flowers and its leaves contributes to potpourris.

Lavender (Lavandula spp.)

From the Latin lavare meaning to wash, lavender is still used today to perfume bath and cosmetic products. Grown from seed (slow to germinate) or cuttings, lavender is one of the most popular plants for the herb garden. The tallest species and probably the best known English lavender (L. angustifolia) is only one of many species including Spanish lavender (L. stoechas) and French lavender (L. dentata). Lavenders require full sun and very well-drained soil. Some herb growers recommend growing lavenders on mounds to ensure drainage. Winter hardy in milder climates, lavender produces white or pale purple to blue-purple flowers and strongly scented needle-like, grey-green leaves. Even the woody stems are fragrant.

Lemon Verbena (Aloysia triphylla)

As it is perhaps the strongest of the lemon-scented herbs, merely brushing by lemon verbena will release a delightful scent. All parts of the plant are scented lemon. Hardy in milder winters, lemon verbena is one of the last of the perennial herbs to leaf out in spring. It grows with abandon, up to 5 feet, and benefits from light pruning. Edible as well as decorative, lemon verbena is also an ideal potpourri plant. It is propagated through cuttings and prefers full sun.

Monarda (Monarda didyma)

Native to America, this tall-growing member of the mint family goes by many names including bergamot, Oswego tea, and bee balm, because it attracts bees. ‘Cambridge Scarlet’ is a cultivar offering bright red flowers in early summer that attract hummingbirds. Monarda leaves have an indefinable, almost lemon scent. Like other members of the mint family, it is a perennial that should be divided about every three years. It may be trimmed back to improve its appearance in late summer.

Mountain Mint (Pycnanthemum pilosum)

A perennial found in abundance in the Appalachian area, mountain mint is a fragrant plant that tolerates shade. About 2 to 3 feet tall, mountain mint develops grey-green leaves at the end of its branches with tiny greenish flowers at the very tip. The plant appears from a distance to have branches ending in white blooms. A popular bee plant, mountain mint needs pruning at least once per summer to control its tendency to grow leggy. Also, mountain mint attracts and provides food for beneficial wasps.

Patchouli (Pogostemon patchouli)

A tropical perennial, patchouli with its exotic Far Eastern fragrance is now available at nursery centers. Patchouli may be grown successfully outdoors in full sun, adequately watered, in fertile soil. When temperatures begin to drop regularly below 65 degrees, it must be brought indoors. An excellent fragrance plant, it may be propagated by seeds, though cuttings are generally used.

Perilla (Perilla frutescens)

This Asian herb, also known as Shisho, is a highly decorative annual garden plant. Direct seeded or transplanted, perilla adapts to full sun or partial shade. The green-leaved variety is a salad herb, but the tall, purple-leaved variety is a striking landscape plant as well. This herb tends to spread from dropped seeds.
Grown by seeding, cuttings, or division, rue has a rich historical tradition. Also known as “Herb of Grace” because it symbolized repentance, rue is today a beautiful ornamental addition to the herb garden. However, its blue-green leaves and yellow flowers in late summer may cause dermatitis in some people. The plant will grow woody with lanky stems if not pruned at least once per summer.

Santolina (Santolina chamaecyparissus)

Santolina is an excellent perennial border plant as it grows between 1 and 2 feet high and is often used in knot gardens. Both gray and green cultivars exist. Santolina produces a strong, perhaps spicy scent when its hard, narrow leaves are crushed. The herb will succumb to heat and overwatering and should be planted in very well drained soil. It is also known as “lavender cotton” and may be used in dried arrangements and in wreathmaking.

Scented Geranium (Pelargonium spp.)

Numerous cultivars are found within this genus, commonly named by their scents — coconut, rose, peppermint, nutmeg, apple, cinnamon, and combinations such as lemon-rose, and others. Most varieties produce small, attractive flowers and leaves that are fragrant when touched. While most are compact, some can grow 2 feet around. They are excellent container plants, and since they are not cold hardy, plants in containers can be moved easily indoors. They will grow in sun or partial shade and prefer sandy soil and minimal watering. Pinched to discourage legginess, they are generally propagated through cuttings.

Soapwort (Saponaria officinalis)

Soapwort, or “bouncing Bet,” is an easy perennial to grow and, unlike most herbs, tolerates moist or dry, poor soil and some shade. It produces white blooms in the summer. Its name comes from the use of its leaves as a mild, sudsing soap-like solution used even in these times for cleaning fine tapestries and other old fabrics (the term “wort” is from the Old English wyrt, meaning root, plant, or herb). It can be propagated from either divisions or seed, and will self-sow.

Stachys (Stachys byzantina)

Perennial stachys, commonly known as “lamb’s ears” for its large, velvety, silvery green leaves, is a beautiful low-growing garden plant producing purple flowers in the early summer. In the same genus as betony, stachys requires minimum water once established; overwatering will cause the plant to “melt” out with deterioration of the leaves, as will shading by other plants. The thick growth also encourages insects on the underside of the leaves. Stachys spreads, though not invasively.

Sweet Woodruff (Galium odoratum)

Sweet woodruff is a favorite herb for shade and makes an attractive ground cover. It may be readily recognized by its narrow, bright-green leaves growing in successive, star-like whorls. The plant is a perennial herb about 6 inches to 8 inches tall.

Tansy (Tanacetum vulgare)

A tall perennial with fern-like foliage, tansy produces yellow button flowers in summer. It grows in full sun and will spread by means of underground rhizomes. Because of its pungent scent, it is sometimes used as an insect repellent. Both leaves and flowers are useful in either fresh or dry arrangements. Formerly used medicinally, tansy is now known to be toxic if ingested.

Yarrow (Achillea millefolium)

Each of the several varieties of yarrow has special characteristics in the landscape, from the fern-like leaves and tall habit of filipendulina to argentea, a smaller, silver-leaved variety. Yarrows are hardy in almost any growing condition, but do best in full sun. They can be propagated by seeding or root division. Yarrows may need to be divided periodically. Remove flowerheads to promote reblooming. The flowers, which include reds, pinks, yellows, and whites, can be cut for their long stalks and dried in bundles for winter arrangements.

Literary Herbs

Poets have used plants to express their thoughts for centuries. Shakespeare wrote of rosemary for remembrance in Hamlet, and about rue, herb of grace, in The Winter’s Tale.

Milton spoke of “sweetest fennel” in Paradise Lost.

The Bible refers to cleansing with hyssop, words bitter as wormwood (artemisia), and fragrance of balm.

Costmary, while not a Biblical herb, was used as a marker in Bibles and as a fragrant herb in churches in colonial time; hence, its name, “Bible Leaf.”


Resource(s):

Herbs in Southern Gardens

Center Publication Number: 263

Seeding Tall Fescue Lawns

Source(s): Clint Waltz, Extension Turfgrass Specialist, The University of Georgia


Tall fescue (Festuca arundinacea) is a popular cool-season grass species that has a bunching to weakly rhizomatous growth habit. Tall fescue is best adapted to Georgia’s piedmont region and is used for home lawns, general areas and for soil stabilization. In general, the southern boundary for tall fescue growth would be Griffin, although, it can be found in shaded or protected microclimates further south.

lawnhouse

 

Because it can be seeded, tall fescue is very popular with do-it-yourself homeowners. Furthermore, its popularity relates to the genetically dark green color during the spring and fall. The use of tall fescue has increased since the introduction of “turf-type” cultivars in the early 1980’s. The turf-type cultivars have darker green color, finer leaf blades, lower growth habit, greater density, and improved shade tolerance compared to the more traditional ‘Kentucky 31’ (K-31) type tall fescues. Additionally, research has shown that some turf-type cultivars have deep extensive root systems and other genetic characteristics for improved drought tolerance.

Establishment

September and October are the ideal months to plant tall fescue. Grass seeded earlier is subject to heat stress and diseases, while planting later leaves the plant vulnerable to cold weather. Seeding in December and early spring is generally not recommended because the plant does not have adequate time to develop a deep root system needed to survive Georgia’s hot summers.

During the summer months, it is common for the canopy of tall fescue to thin and become more open. This is a heat-stress survival mechanism that allows the plant to conserve energy until climatic conditions are favorable for growth. However, a thinned and open canopy makes the tall fescue less competitive and more susceptible to summer annual grassy weeds, like crabgrass. Preemergence herbicides are needed to minimize weed pressure, but research has shown that these herbicides pose the least amount of risk to tall fescue that was seeded the previous September and October. Tall fescue seeded in November and then treated with preemergence herbicides the following February had lower turfgrass quality ratings and reduced stand density compared to tall fescue seeded in October.

Soil Preparation

Proper soil preparation is critical for an effective seed establishment. Ridding the lawn of debris, tilling, incorporating lime and fertilizer, and smoothing the surface are all necessary prior to seeding. Add any amendments such as organic matter or topsoil for soil improvement and till thoroughly into the existing soil. After initial preparation is completed and the area is properly leveled, collect a soil sample to obtain soil fertilizer recommendations. Then incorporate the starter fertilizer and lime 3 to 4 inches into the soil before planting. If equipment permits, tilling deeper is always better.

Seeding

To ensure varietal purity plant seed that is certified and identified by a blue tag. Such seed has been tested and the information on the label is assured by law. In the retail market most tall fescue seed is available as a blend, where several tall fescue cultivars are blended together. Single cultivars are also available but often at a higher price compared to blends. Orchardgrass is a common weed seed contaminate found in tall fescue seed and is easily seen in lawns because of its blue- green color and faster growth rate. Unfortunately, it cannot be selectively controlled with a herbicide.

The ideal seeding rate for tall fescue is 5 pounds per 1,000 square feet. To minimize skips and gaps, it is best to divide the seed into two equal portions and broadcast half in one direction and the remainder at a right angle to the first direction. This procedure is also recommended for fertilizer and granular pesticide applications. The seed can be lightly raked into the upper ¼ inch of soil or pressed into the seedbed with a roller. Applying a straw mulch to retain moisture for improved germination and prevent erosion can be beneficial.

Irrigation

After seeding, keeping the upper 1 to 2 inches of soil moist, not wet, is necessary for uniform germination. This usually means daily watering of about 1/8 to ¼ inch for the first three weeks. As the seedlings develop, irrigate less frequently but wet the soil profile deeper. Under good conditions tall fescue seed will germinate in 5 to 10 days and be ready for its first mowing between 2 and 3 weeks.

Mowing

Begin mowing at a height of 2 inches and as the seedlings mature, raise the cutting height to the 2 ½ to 3 inch range. Once mature, the lawn can be maintained between 2 to 2 ½ inches, but a height of 3 inches is suggested during the summer months. Use a mower with a sharp blade and mow often enough so no more than 1/3 of the leaf height is removed in a single mowing. Do not mow a grass when it is wet, especially young seedlings.

Reseeding

It is common for tall fescue lawns to thin and need periodic reseeding. Turf thinning is usually caused by environmental stresses, improper turf management like insufficient irrigation, too much nitrogen fertilizer, seeding with more than 5 pounds of seed per 1,000 square feet, mowing too low or too high, and seeding in late fall or spring. Additional problems include pests like crabgrass or white grub infestation, or disease problems like brown patch. Soil related problems like a hard compacted rootzone, and environmental conditions where tree shade and root competition compete for water and nutrients also contribute to canopy loss. All of these factors, however, can be mitigated with proper management.

If the lawn needs reseeding, estimate the percentage of tall fescue loss and multiply that number by the establishment seeding rate of 5 pounds per 1,000 square feet. For example, if 50 percent (0.5) of the stand is lost, reseed with 0.5 x 5 = 2.5 pounds per 1,000 square feet. Spring reseeding is less successful because of the shorter establishment time before summer heat and moisture stress.

Getting the seed in contact with the soil is necessary to assure successful reseeding. First, mow the lawn at a height of 1 to 1.5 inches. Disturb the soil preferably by coring or vertical mowing before and/or after seed distribution. This equipment is often available at rental or garden centers. Reseed thin areas at 2 to 5 pounds per 1,000 square feet. Getting the seed below the existing turfgrass canopy and to the soil surface improves germination. Apply a starter fertilizer at 1 pound of nitrogen per 1,000 square feet at this time. Finally, keep the soil moist as discussed for new lawn establishment.

In summary, successful seeding depends on proper soil preparation, good soil-to-seed contact and, proper water management. This and other fact sheets are available at www.gaurbanag.org and www.georgiaturf.com.


Resource(s):

Lawns in Georgia

Center Publication Number: 218

Selecting a Christmas Tree

Source(s): Gary R Peiffer


Determine where in your home you will display your tree so that you will know at the tree lot what size and shape you need.

 

Do a freshness test. Hold a branch about 6 inches from the tip. Pull your hand toward the tip, allowing the branch to slip through your fingers. Very few green needles should come off in your hand if the tree is fresh.

Another freshness test: lift the tree a couple of inches off the ground, then bring it down abruptly on the stump end. The outside, green needles should not fall off in substantial numbers. Remember, inside needles do turn brown and shed naturally every year.

A good fragrance and green color also indicate freshness.

CUT TREE CARE

Bring several plastic garbage bags or a large sheet of plastic when you go to purchase your tree. Wrap the tree with plastic if you plan to transport it on top of your car. Cold winter air at 60 mph will dry the tree further and can cause early needle drop.

The most important thing to remember is that real trees need water. Research has not shown much benefit from using “freshness extender” chemicals. They seem to work well for flowers but results are more uncertain for trees.

Make a fresh cut across the base of the trunk, 1/4″ up from the original cut.

When a tree is first cut, a seal of sap occurs naturally over its stump, which keeps moisture in the tree. It’s important to break that seal to allow the tree to take up the water needed to keep it fresh throughout the holidays.

Until you are ready to decorate, keep your tree outdoors, standing in a bucket of water and protected from the wind and sun. This will help the tree retain its moisture.

Keep plenty of water in your stand. A Christmas tree may absorb a gallon of water in the first 24 hours it’s up and two pints to a gallon of water a day thereafter. Check the stand daily and supply fresh water as needed. Never let your tree stand go dry. If the water supply runs out, a seal will form on the cut surface of the tree trunk and a new cut should be made.

Position your tree away from heat sources such as fireplaces, radiators and television sets.

Test your light cords and connections before hanging them on the tree to make sure they are in good working condition. Look for cracked insulation or broken sockets, and make sure all the sockets are filled. Don’t forget to unplug the lights when you go to bed or leave home.

LIVE CHRISTMAS TREES

Several kinds of evergreen trees can be bought as live Christmas trees and then planted after the holidays. It is important to remember that live trees take much more care than cut trees. Live trees should be kept inside no more than two weeks.

LIVE TREES FOR THE ATLANTA AREA

White pine
Leyland Cypress
Virginia pine
Canadian Hemlock

Note: Fir and spruce trees have difficulty surviving hot Atlanta summers. They are not recommended for planting in this area.

HOW TO CARE FOR LIVE TREES

Leave outdoors in a shady spot until mid December. Spray with an anti-transpirant such as Cloud Cover or Wilt Pruf.

Transport indoors on December 15. A child’s wagon, lined with plastic, makes a good cart. The tree can be left in the wagon or it can be set into a wide, shallow pan indoors.
Water the root ball every day. Use at least two quarts of water each time. Pour the water slowly on top of the root ball and allow it to soak in. Do not just pour water into the pan.
Close all hot air vents near the tree. Try to keep the room cool for most of each day. Close all hot air vents near the tree. Try to keep the room cool for most of each day.
Move tree outdoors by December 28. Dig a hole five feet wide and 12 inches deep. Plant the root ball in the center. Apply lots of water. Mulch with three inches of pine straw.
Water weekly until spring. Fertilize with liquid plant food (MiracleGro, Peters, etc.) in mid-summer.

The mention of brand names in this publication does not imply endorsement or exclusion by the Cooperative Extension Service.

RECYCLING TREES

Place your tree in a garden or backyard for use as a winter bird feeder and shelter. Orange slices, bread and suet will attract birds and brighten up the winter landscape.
Christmas trees are biodegradable. The branches and trunk may be removed and chipped to be used as mulch in your garden. Contact your local Clean and Beautiful office for recycling sites.

4 Branch tips and needles provide aromatic stuffing for sachet.

Sunk into private fish ponds or lakes, trees make excellent refuge and feeding areas for fish.
Living Christmas trees can be planted in the yard and enjoyed for years to come. If there is no room in the home landscape, trees can be planted at schools, churches or neighborhood beauty spots.

SOURCES OF TREES

All Local Nurseries
Send self-addressed, stamped envelope to:

Georgia Christmas Tree Association
Cut Tree Guide & Farm List
Route 2, Box 104
Midway, Georgia 31320

Farmers & Consumers Market Bulletin
Thanksgiving week issue
Call 404/656-3645 or 1-800-282-5852

Shade Tree Decline

Source(s): Kim D. Coder, Professor of Community Forestry, Warnell School of Forestry and Natural Resources, The University of Georgia


Many trees in Georgia are showing dieback and decline symptoms. Twig or branch dieback is initiated in the tree as a response to poor growth conditions and/or pest attack. Usually a combination of physical, climatic and pest problems lead to the tree shutting off some of its outside portions.

shadetree

Tree decline is a general loss of vitality throughout the entire tree caused by a systemic disease or by a sequence of stressing events that cause the tree to burn too much food energy. Many cultural factors as well as past tree abuse predispose a tree to decline. Several factors contributing to this decline include, drought, mechanical injury, chemical injury and pests.

Drought

Drought is a main contributing factor to shade tree decline. Extended drought can influence the health of shade trees by the loss of absorbing roots which are found primarily in the top 8 to 12 inches of soil. Once this soil area dries, many of the tree’s absorbing roots dry out and die. Leaves and stems can also be damaged by drought conditions, especially when there is not enough water available for evaporative cooling and food production.

Some types of trees will be inherently more susceptible to drought damage that occurs in mid-spring as compared with a summer drought. A season-long drought period with high temperatures can adversely effect all trees even if supplemental water is added. Trees may not readily show initial symptoms because of stored carbohydrates and essential elements in the woody tissues. As soon as these stored foods are near depletion, the trees begin to prematurely defoliate. Other drought symptoms can be delayed two or more years making it hard for many to believe that drought was actually the problem.

Although irrigating trees during periods of drought is recommended, frequent and shallow watering contributes to shallow root development. This increases the chances for drought injury as well as the potential for winter injury during periods of extremely cold weather. When watering, be sure the moisture reaches depths of at least 5 to 7 inches. Water once every three to four days during periods of severe drought. Watering everyday may contribute to the decline of the tree because the activity of many parasitic and pathogenic organisms, like root rot, is stimulated by too much water. The amount of water to apply depends upon soil texture and potential size of the tree rooting area. Clay soils can be easily overwatered which destroys tree roots.

Mechanical Injury

In urban areas, mechanical injury is a major cause of shade tree decline. In subdivisions and new housing developments, shade trees are often abused; roots are torn out of the ground, bark is bruised and the soil around trees is disturbed. Losses from such damage could be minimized or even avoided if people realized that trees may not survive such treatment and took precautions to avoid abusing them. Many utilities and municipalities are also guilty of tree abuse. When putting in gas and water lines or paving streets, workers damage or destroy roots which disturbs food production, growth control and the tree’s top-root balance. Root loss contributes to the weakening and decline of a tree’s crown. As with drought, these symptoms can often be delayed in appearance by 1 to 2 growing seasons.

Some of the worst things you can do to a tree are: add fill around the trunk, cultivate or remove soil from around the trunk, compact the soil, especially when the soil is wet, or damage the bark on the trunk. Each of these events leads to a weaker tree that can lead to other stress factors or pests injuring the tree further.

Chemical Injury

Chemical damage (pollution/pesticides) of trees is very common. Injury to trees from pollution as well as chemical application by homeowners and commercial applicators, are common occurrences. Pollutants are now a part of our urban and rural environment and ecology. Pollutants, such as ozone, sulphur dioxide, fluorides, sunlight-induced nitrates (PAN), road and sea salts and particulate matter (flyash, dust, cinders), all disrupt the life processes of trees. Some pollutants will be concentrated near roadways and factories that are their source. Other pollutants, like ozone, can disrupt tree growth a hundred miles downwind from a city. Pollution acts as one factor in a tree decline problem.

Chemical injury can be much more severe when trees are already weakened by other factors. The “spray and pray” concept (spraying a chemical and hoping it will control whatever the problem is) should be avoided. Chemicals are not always the answer and may actually create more problems. Good tree management should be practiced first. Use chemicals only as helpers after other management practices have been performed.

Pests

All of the factors already mentioned, and others not mentioned, weaken trees and make them more susceptible to pest organisms. Disease organisms are especially likely to take advantage of a weak tree.

  • Tree Cankers: Many oak species are lost to Hypoxylon canker, a disease that is common in both urban and rural areas. This disease can be diagnosed by its grayish to brown felt appearance on the bark. Little can be done to control this disease since the fungus is actually growing into the wood of the tree. The removal of infected trees and pruning of infected branches will remove the fungus innoculum from the area. However, pruning will not solve the problem of low tree vigor. Careful management practices performed to increase tree vigor will encourage tree recovery.
  • Twig Cankers: There are a number of canker-causing fungi which cause twig dieback in many shade tree species. Most are diseases that take advantage of trees that are in a weakened or declined condition. Prune dead wood and initiate management practices to help the tree recover. Fungicide applications generally provide little protection since tree health is the key to canker disease control.
  • Leaf Spots: There are numerous leaf spot fungi which infect leaves and cause foliage loss from many urban shade trees. These diseases occur annually and may actually go unnoticed most of the time. During periods of stress, there may be an excessive amount of defoliation attributable to foliage diseases. Foliage diseases of large urban trees are not known to cause any permanent damage unless defoliation occurs several years in succession. Excessive defoliation often occurs when a tree is in a weakened condition.
  • Slime Flux: Slim flux, called wet wood, is considered a disease of unthrifty or old trees. Symptoms of slim flux include oozing of either a white or brown, smelly substance from wounds, pruning scars and trunk crotches. The slime is toxic to the bark and may kill large patches when it stays on the bark for a long time. Rinsing twice a year may minimize the damage, but determine what weakened the tree initially and provide best management practices to improve tree vigor.

Decline Management

What can be done to prevent shade tree decline? The key to good health is tree vigor. Provide a site that is suitable for the species involved. Pick a strong species of tree. Provide construction protection for roots and trunks of trees to reduce accidental injury, soil compaction and to allow adequate room for tree growth. Plan ahead for future development. Street maintenance equipment often injures trees after roadways are widened. If twig dieback is observed, proper pruning will reduce disease susceptibility and improve the tree’s appearance. Remove dead or dying branches. When roots are damaged or lost, continue to water and wait one growing season and then thin the crown. This helps the remaining roots sustain the health of the existing foliage. Water, fertilize and care for the tree only when needed. Do not “kill” your tree with kindness. Give your tree a chance to live a full, healthy life by helping when it has a bad year.

Shade tree decline is becoming much more prominent. Being able to recognize conditions which promote decline and taking steps to eliminate stresses before symptoms occur will save many urban shade trees.


Center Publication Number: 223

Shot-hole Disease

Source(s): Nina Eckberg


Shot-hole disease is a combination bacterial infection (Xanthomonas prunii) and fungal disease (Blumeriella gaapi and/or Cercospora sp.).

Shot-hole Disease

Shot-hole Disease Identification

Shot-hole disease (on a laurel in the photos) is a combination bacterial infection (Xanthomonas prunii) and fungal diseases (Blumeriella gaapi and/or Cercospora sp.)

Shot-hole Disease Appearance

Circular holes in the leaves that eventually join and make larger holes. The appearance of shooting a shotgun at the shrub and causing multiple holes.

Shot-hole Disease Hosts

Laurels (bay and Otto Luyken), camellia, ligustrum (privets), hydrangea, ivy.

Shot-hole Disease Season

April through October, peak in May and September.

Shot-hole Disease Damage

Leaves appear to be ‘eaten’ away by the disease, leaving a ragged appearance. As leaves are damaged, they begin to fall away, the plant looses its ability to make food and can become stressed.

Shot-hole Disease Integrated Pest Management

Sanitation is the best way to keep the disease from coming back. Clean up contaminated leaves from under the plant. When diseased leaves build-up under the plant, rain or watering can splash the disease back up on the plant. Spray the leaves with Mancozeb, Kocide, Kop-R-Spray or other recommended products containing copper at the first sign of a problem. Always READ THE LABEL and DIRECTIONS FOR USE section carefully when using pesticides.


Resource(s):

Common Landscape Diseases In Georgia

Center Publication Number: 55

Sinkholes In The Landscape

Source(s): Walter Reeves, College of Agricultural and Environmental Sciences, Former County Extension Agent – DeKalb County


Sinkholes in the yard are an unfortunate but common problem that may arise five to ten years after a home is constructed. These holes, or underground cavities, form gradually but can appear in your lawn overnight.

In Florida, where some homes have been built on top of underground limestone caves, a sinkhole is a serious situation. In the northern half of Georgia, sinkholes like these are rarely seen.

Sinkholes typically develop where construction crews have buried debris, such as tree branches, stumps and construction materials. After a few years this buried debris decays. This leaves behind a large underground cavity hidden by a relatively thin surface layer of soil and grass. The soil layer eventually caves in, causing a sunken area or hole that can seem bottomless.

1f a sinkhole appears in your lawn, inspect it carefully to determine if the problem was caused by buried debris. Enlarge the surface opening so that you can inspect the entire cavity with a flashlight. If you can see traces of decayed trees or building materials, you have a construction sinkhole. By probing the bottom and sides of the cavity with a long rod, you can confirm your suspicions. If you find solid earth on the bottom and sides, the cavity probably is man-made, and can be treated with one of the remedies listed below.

If you find a large pipe in the cavity, a leaky sewer pipe may have caused the sinkhole. Rainwater might have washed soil into the pipe. As the soil is taken away, more soil washes in and the ground above sinks. The best course of action is to consult the proper municipal authority before proceeding any further.

When the cavity is so large that you cannot reach the sides or the bottom or if you see lots of water or soft, mucky soil, you could have a more serious problem. A private geotechnical or soils consultant should be contacted to inspect the site and recommend a solution.

Treating Underground Cavities

  1. Check the location of buried utility lines before you dig. Call 1-800-282-7411 within Georgia and 404-325-5000 within metro Atlanta for free utility location services.
  2. Enlarge the surface opening to access the entire cavity. Look for decaying debris and confirm the cause of the problem.
  3. Remove any large pieces of undecayed debris.
  4. Fill the entire cavity by adding loose fill dirt in 12-inch layers. Pack the soil firmly after each 12-inch layer to prevent future settling. Failure to pack the entire cavity may cause another sinkhole in the future.
  5. Once the cavity is filled, establish grass or other plants on the bare soil. It is probably not a good idea to plant a tree in this area for at least a couple of years. After that time, you can be relatively sure your problem is solved.

Center Publication Number: 32

Slow The Flow – Make Every Drop Count

Source(s):

  • Joan E Marsh
  • Gary R Peiffer

Make every drop of water count so that everyone has enough to use all summer long.

General Watering Tips

  • When watering, wet the soil to a depth of about 6-8 inches which is about one inch of water. Short, surface waterings do more harm than good by encouraging shallow roots.
  • Three to five gallons of water, or less than one minute of watering with a garden hose, will saturate the root zone of a plant.
  • Established shrubs can survive with one 30 second hand-watering into their root zones every 2-3 weeks.
  • When installing new plants, especially large trees and shrubs, build a shallow soil bern (2-3 inches high) so that water can be directed to the plant’s root zones.
  • If possible, consider doing larger plantings during the fall to early winter, or in early spring when there is more adequate rainfall.
  • Trickle, drip or soaker irrigation systems provide adequate water for plant growth and reduce the amount of water used by 80-90%. Most of these systems put out 1-3 gallons of water per hour, and the water goes right to the plant’s roots where it is used.
  • Before deciding how long to run your watering system, test it to see how much water it puts out over a desired time period.
  • Watering plant leaves and/or stems increases your chances of pest problems, especially diseases. Also, it wastes water because very little to no water is absorbed through these plant parts.

Ornamental Plants – Watering Needs

  • Many southern landscape plants can tolerate drought conditions for several days and even weeks once they are well-established (after first 2-3 years). Examples: crape myrtles, junipers, many holly varieties.
  • Place large, valuable and historic trees at the top of your watering priority list. Large oaks are especially vulnerable to drought conditions and you can not easily replace 100 year old oak trees.
  • Most annuals, perennials, and many shrubs (azaleas, rhododendrons) are shallow rooted and therefore have high water demands. Water them more often but limit the size of these planting areas.
  • If planting color areas, such as annuals/perennials, concentrate them in containers or planter boxes, and use some water-holding polymers in your mixes.
  • Water newly planted trees and shrubs BEFORE well-established mature plants. They will need at least 1-2 good waterings per week, to get rooted and to insure their survival.
  • Hold off on the installation of new plants during the driest months of the year (usually June- end of August).
  • Plants growing in shade generally require less water than those in full sun.

Avoid Plant Stress

  • Do not fertilize drought stressed plants. Fertilizers are salts which dehydrate plant roots when the soil is dry. Encouraging plant growth during a drought is not what you want. New growth requires the use of even greater water resources.
  • Drought stressed plants are weakened and more prone to pest attacks.
  • If applying pesticides, follow label precautions and do not apply to a plant that is already wilted or during the hottest hours of the day.
  • Avoid unnecessary pruning. Pruning stimulates new growth which again requires more water.

Mulch

  • Install a 3-4 inch layer of organic mulch (leaves, pine straw, etc.) over plant root zones to conserve soil moisture.
  • Mulch entire root zone 6 inches out from the stem to the tip of the plant’s drip-line (ends of its branches).
  • Do not pile mulch on lower stems or it will encourage rotting and pest problems such as voles.

Turf

  • Most turf grasses can get by on 1 inch of water per week. This can be supplied by one to two good waterings, but you must know how much water your system puts out.
  • Tall fescue grasses are not as drought tolerant and they may require up to two inches of water per week. Mowing fescue as high as possible, 2 to even 3 inches, will help shade its roots and limit drought stress.
  • The best time to water a lawn is between sunset and sunrise while it is already experiencing its natural wet cycle (dew period). However, follow your local water restrictions as required and do not water until after 10 PM.
  • Mow all turf less frequently during dry weather and only remove 1/3 or less of the blade height per mowing. Grass-cycle and leave those clippings on the soil to shade grass roots and provide nutrients.

Trees

  • Do not fertilize drought-stressed or weakened trees.
  • Water deeply by establishing soaker or drip hoses at the tree drip-line (branch tips). Provide one to two good soakings per week.
  • Do not water at the base of trees or onto foliage.
  • Watering leaves in the daytime can cause leaf scorch and watering leaves at night promotes leaf diseases, like mildew, and leaf spots.
  • Establish natural areas or mulch islands under your larger, valuable trees.
  • Leave an air space at trunks, but place mulch over as much of tree root zone as feasible.
  • Limit plant competition by not over-planting in tree root zones.

Slow the Flow – Make every drop count so that everyone has enough drops to use all summer long. This is not just water conservation, it is a wise and equitable use of our natural resources.


Center Publication Number: 43

Snakes and Their Control

Source(s): Michael T. Mengak


No other creatures provoke such simultaneous conflicting feelings as do snakes. We are at once attracted and repelled, intrigued by them and their habits and, at the same time, certain people are seized by an almost overwhelming urge to kill. As with any wild animal, caution is advised. Homeowners, hikers, hunters, children and others should not approach or threaten any wild animal, and snakes are no exception.

snake

A major reason many fear snakes is that some are venomous. Of the more than 50 kinds in Georgia, however, only 6 species or about 12 percent are venomous. Our venomous species are Eastern Coral Snake (Micrurus fulvius), Copperhead (Agkistrodon contortrix), Cottonmouth (Agkistrodon piscivorus), Pygmy Rattlesnake (Sistrurus miliarus), Timber Rattlesnake (Crotalus horridus), and Eastern Diamondback Rattlesnake (Crotalus adamanteus).

Fortunately, snakebite is a rare accident. Fewer people are killed by snakes than by lightning. The best defense is knowledge; learn to recognize venomous species. Snakes of Georgia and South Carolina by Whit Gibbons and Patricia West (editors) is a good reference for snake identification. This booklet is available for $5 from the Savannah River Ecology Laboratory in Aiken, SC, the University of Georgia Cooperative Extension Service or your local county extension agent.

Snakes feed on a wide variety of small creatures and are very particular about what they eat. Some species eat only warm-blooded animals such as rodents and birds. Others may eat only toads and frogs. Large land-dwelling snakes are likely to feed on rodents, birds and their eggs, lizards, other snakes, toads and frogs. Aquatic snakes feed primarily on fish and amphibians. Small snakes are likely to eat mice, frogs, toads, earthworms, slugs and soft-bodied insects. Thus snakes are part of the natural system. Many of the things they eat are considered pests, so knowledgeable people spare harmless snakes that live in their yards.

Venomous snakes are another matter. In most circumstances, they should be removed. Be careful – a snake can strike half its length or more. Even when the snake is dead, its reflex movement can result in a bite if handled carelessly. Bites by venomous snakes need prompt medical attention. The bites of non-venomous species can be treated with soap, water and antiseptic.

Any non-venomous snake can be safely removed from a building by using a long-handled broom to gently brush the animal into an empty trash can. Place the lid on the can and take the snake to a wooded area away from any homes and carefully release it.

Refer venomous snakes in buildings to the Wildlife Resources Division of the Department of Natural Resources. Most people are bitten when they try to kill a snake. This only causes the snake to defend itself the only way it can.

The following plan of action will reduce the severity of a snake bite:

  • Stay calm. The snake may be non-venomous, but if it’s venomous, excitement hurts, not helps.
  • Have someone kill the snake so it can be identified. Use extreme caution. Most snakebites occur when attempting to kill the snake.
  • Get to competent medical help as quickly as possible.
  • Ask your doctor what he or she advises regarding snake bite – before it happens.

What attracts snakes to dwellings? If the house is surrounded by natural countryside with rock piles, streams and swamps nearby, snakes will appear from time to time. Naturalistic landscaping, rock gardens, weedy places, piles of boards and debris, deteriorating outbuildings and other similar things may harbor snakes.

Since there are no chemical poisons or effective repellents registered for snake control, the best way to make yards and outbuildings unattractive to snakes is to clean up and clean out. Snakes cannot hear sound, so auditory repellents are ineffective.

The first step is to ensure that there are no openings in dwellings or other structures where snakes can enter. Since snakes can get through very small holes (about the size of a dime), a careful inspection is necessary. For additional information, check with your local county extension office.

At the same time you are keeping snakes out of the house, take steps to make the rest of the premises unattractive. Look at the surroundings as if you were a snake. Are there rodents or other sources of food? Are there places to hide? If the answers are “yes,” plan a program to remove food and cover.

  • Control rodents if they are present.
  • Get rid of debris.
  • Remove brush and leaf piles.
  • Place stacked materials 12 or more inches above the ground or floor and away from walls.
  • Keep the space beneath structures and stacks clean.
  • Keep shrubbery and other plantings away from foundations and walls.
  • Keep shrubbery clean and free of debris. Keep lawns closely mowed. Fill unwanted depressions.
  • Keep stream or pond banks clean and clipped.

These practices will reduce but not eliminate the possibility of finding snakes. Remember, it is best to remove items that a snake would find attractive. Do not try to handle them.

Enjoy their presence by observing them from a safe distance. They are highly evolved predators that have a natural role in the environment. Especially remember that the vast majority are secretive, harmless to humans and beneficial in controlling mice, insects and other pests.


Center Publication Number: 212

Sneezeless Landscaping

Source(s): Gary R Peiffer


About one out of five persons suffers from allergies, many of them plant related. Flowers, trees and lawn grasses in our backyards product billions of pollen grains each spring. Georgia’s pollen season is at its peak in mid- April, receding in mid-May, and resurfacing in mid-August.

Some plants pollinate by insects and animals, others are wind-dependent and shed pollen into the air currents on warm, dry days intending to land on flowers. Instead, these tiny particles are easily inhaled by people and adhere to the linings of the nose, throat, and eyes. A chemical (histamine) is then released by the body that will induce allergic symptoms in sensitized individuals producing sneezing, coughing, itching, and watery eyes.

Plants pollinated by insects and animals tend to have large, sticky pollen grains that are not airborne, posing much less problem to the allergy sufferer. Pine pollen is often accused of causing allergies, but is not a potent allergen and is too large to go deep into the respiratory tract.
Although pollens can travel many miles, the majority tend to be focused in the general vicinity of their origin. An oak tree in the yard can expose the homeowner to ten times more pollen than an oak tree a block a way.

During the height of the pollen season–from late February to June–there are often thousands of pollen grains in every cubic meter of air. Most airborne pollen is so small it is barely seen. The amount of pollen in the air varies mile to mile and hour to hour, depending on local vegetation, wind direction and velocity, and other weather conditions. Pollen counts are higher on sunny, dry days and lower on cool, cloudy days, or after a rainfall.

Coping with Allergies

When the pollen counts rise, close your windows and don’t use window fans, stay in air conditioning, change air conditioning filters often.
Pollen counts are higher in the morning, so outdoor activities – such as running or cutting grass – should be done in the late afternoon.
Keep your car clean and use the air conditioner.

If you wear contact lenses and have allergic eye symptoms, a regular pair of glasses is much better for you at this time of year.
Wear glasses or sunglasses outdoors to prevent pollen from irritating the eyes.
Wear a paper mask that covers your nose and mouth when doing yard work, (available at drug and hardware stores).
Use gloves when gardening or wash your hands often.

Shower and put on fresh clothes after spending a lot of time outdoors, wash your hair particularly if you have long hair.
Wash pets (especially dogs) regularly because pollen clings to their coats. Consult your physician if you experience ongoing symptoms such as a runny nose, stuffiness, sinus pressure and headaches along with coughing and wheezing.

Use antihistamines sparingly, always with your doctor’s advice.

Do not use over-the-counter nose sprays more than three consecutive days; you can become tolerant to the medication rendering it ineffective.
Hay fever sufferers and allergic asthmatics participating in sports on grassy areas should take medication at least an hour before play.

Planting Recommendations

Many plants can be used in place of allergy producers. All plants, however, have the potential to cause allergies if the exposure is high enough. For example, a florist may become sensitized to flowers listed here as ‘sneezeless,’ after close and frequent contact with the pollen.
People with allergies and asthma have sensitive airways, which can be adversely affected by slight irritants, such as plant fragrances. Other irritants which can trigger nasal distress or asthma include dust, secondhand smoke, pollution, and perfume. Some plants known to cause problems among sensitive persons include the rose, star jasmine, citrus tree, eucalyptus tree, narcissus, rosemary, and gardenia.
One way to select “sneezeless” plants is to examine the flowers. Plants that produce the most frequent allergies are wind-pollinated. Their flowers are drab, inconspicuous, and often in clusters or tassels (called catkins). Frequently, wind-pollinated plants have separate male and female flowers, or entirely separate male and female plants.
Most colorful and showy flowers are “safe.” They are insect-pollinated and their beautiful petals serve to attract bees and other insects. Their pollens are usually heavy, sticky, and have a variety of surface structures. such as spines. The pollen grains can easily and securely attach to the insect and are not easily picked up by wind currents. These pollens seldom cause allergies.

A Word About Lawns

Bermuda grass lawns in particular produce abundant pollen, and the common seeded bermuda more than the hybrid. Bermuda grass can pollinate when the lawn is very short, as quickly as a few days after mowing.
Of the grasses, blends of perennial rye grass, blue grass, and tall fescue are recommended or other varieties of bunch grasses. They are available from seed or as sod lawns and will not flower unless allowed to grow 12″ or higher. The recommended mowing height is about 2″. Therefore, a well-maintained lawn of only bunch grass is also essentially allergy- free.

If a bermuda grass lawn is already present, someone other than the allergic person should mow and edge it as frequently and as short as possible. By keeping it watered and fed properly, flowering may be somewhat inhibited. Remove runaway bermuda grass from flower beds because it will flower prolifically.

Weeds

Ragweed is the dominant allergy producer in the fall. Other weeds that are common allergy producers include grasses, nettle, dock, English plantain, tumbleweed, pigweed, lambs quarters, and other members of the Amarantheceae and Chenopodiaceae families.

Soap, Oil, and Bt Products Control Most Garden Insects

Source(s): Keith Mickler, Floyd County Extension Agent, College of Agricultural and Environmental Sciences.


The majority of pest insects can be controlled with one of three environmentally friendly products – Horticultural Oils, Insecticidal Soaps and Bt Products.

 

Horticultural oil is especially formulated for use on plants. It is a petroleum-based oil with an emulsifier added that allows it to mix with water. It kills scales, mites, aphids, whiteflies and other soft-bodied pests that are present by suffocation, plugging up the insects breathing pores.

Horticultural oils are classified as dormant oils, summer oils or superior oils. Dormant oils are the heaviest of the horticultural oils. Apply these oils during winter dormancy and before plants begin spring growth. Do not use dormant oils during the growing season unless the label specifically states that such use is safe.

Summer oils are lighter than dormant oils and are formulated for use during spring and summer. Superior oils are the most refined of all petroleum oils and are excellent products for horticultural pest control in any season. Superior oil products allow greater flexibility in their use and have been tested at temperatures in the mid 90s with no damage to shrubs.

Only a few of the soaps manufactured are effective insecticides. insecticidal soaps basically are made from potassium salt of oleic acid, which is present in high quantities in olive and other vegetable oils. Insecticidal soap causes insects to dehydrate by physically breaking down the insect’s outer protective layer (cuticle).

Thorough spray coverage is essential when using oils and soaps. Since these products are not poisons and must contact the pest, all plant surfaces, tops and bottom sides of leaves and stems must be coated with spray for best results. Horticultural oils are sold under various descriptive names such as “dormant oil,” “oil emulsion,” “pesticide oil,” “summer oil” and “superfine oil.” There are several soaps available for purchase, such as Safers Insecticidal Soap and M- Pede.

Another environmentally friendly product for controlling caterpillars is Bt (Bacillus thuringiensis). Bt is an insecticide stomach poison for use only against caterpillars. Bt should be used when the caterpillars are young. The caterpillar must ingest the Bt for it to be effective. After ingesting a lethal dose of Bt, the caterpillar stops feeding and will die within several hours to days. Bt can be found under several brand names such as Dipel, Thuricide and Sok-BT.

Though horticultural oils, soaps and Bt products are less toxic than many insecticides, it is important to use them with caution. Read and follow the label carefully.


Resource(s):

Insect Pests of Ornamental Plants

Center Publication Number: 270