Center for Urban Agriculture

Source(s): Gary R Peiffer

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Powerful tornadoes and thunderstorms often rake across Georgia in the spring. Trees fall, limbs are snapped and landscapes are devastated. After a storm, homeowners, landscapers and tree companies are faced with mounds of wood chips that must be used on site or taken to a local composting facility.

Homeowners may have questions about using chips in their landscape. Here is a collection of pointers from Dr. Kim Coder, Extension Forest Resources Specialist:

• The use of chips as mulch for shrubs and trees is absolutely their best use. Chips conserve moisture, prevent weeds and grass growing in the root area and keep the plant roots cool.
• The appropriate thickness of the layer of chips depends on the proportion of “fuses” in the mix. If you hold a double handful of the chip mix in a breeze and let it sift through your fingers, the fines (small pieces of leaves and needles) blow several feet away. The heavy, coarse chips fall to the ground quickly.
• If there is a high proportion of fines, the chip layer should be 2 inches thick.
• If the mix is mostly coarse chips, the layer can be up to 4 inches thick.

Homeowners may be worried about the chips poisoning their plants. In scientific terms, this is called “allelopathy”. You are probably aware that black walnut trees prevent many plants from growing underneath their canopy. But walnut chips exhibit very little allelopathy. In fact there is rarely a reason for a homeowner to be concerned with this problem. Only in unusual circumstances do wood chips inhibit woody plant growth. If a chip pile is rained on a few times before it is spread, all of the tannins from oak trees (which might harm willows and shallow-rooted trees) will be washed out.

Use caution before spreading pine chips under pine trees. The chips are strongly attractive to the black turpentine beetle and moderately attractive to the Southern Pine Beetle. It is best to use pine chips under hardwood trees and shrubs. Use hardwood chips under pine trees.

Suggested uses for wood chips:

• Mulch
• Parking areas
• Nature trails
• Dog runs
• Playgrounds
• Soil amendment (if piled in one place to rot for two years)

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Resource(s):

Composting and Mulching

Center Publication Number: 21

Source(s): Maxcy P. Nolan, Former Extension Entomologist, College of Agricultural and Environmental Sciences.

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The carpenter bee, Xylocopa virginica (Linnaeus), normally attracts quite a bit of attention in Georgia in late spring and early summer. Since it closely resembles the bumble bee, is quite large and attacks wood around homes, it can become an important household and structural pest.

APPEARANCE

Adult carpenter bees are large, one inch or slightly longer, robust insects. They are blackish in color and possess yellowish hairs mostly on the thorax. The abdomen is shiny black and is bare of hairs on top. This helps distinguish carpenter bees from bumble bees which are similar in size and coloration but bumble bees have yellowish hairs on top of their abdomen.

Carpenter bee eggs, larvae and pupae are seldom seen since they are out of sight in cells within galleries constructed in wood. When wood containing carpenter bees is opened to expose the immature, larvae are legless, white grubs and pupae resemble adults.

DAMAGE

Carpenter bees burrow into the exposed dry wood of buildings, telephone poles, fence posts, etc. causing an unsightly appearance to the wood and structural weakness. They usually choose wood that is soft and easy to work. They seem to particularly prefer California redwood, cypress, cedar, white pine and southern yellow pine. Other woods, even seasoned hardwoods, may be attacked if they have been softened by being unprotected and exposed to the weather for extended periods of time. Bare wood is preferred. Carpenter bees usually avoid well-painted wood and wood with bark on it. Wood with a stain or light coat of paint can be attacked. Also, wood that has been lightly pressure treated with metallic salts for above ground use, such as for decks, could become infested.

Female carpenter bees use their mandibles to bore 1/2 inch round holes into wood. About one inch of gallery is constructed every 6 days. Galleries normally run with the grain for 4 to 12 inches or even further when old galleries are extended.

Female carpenter bees seldom sting but when disturbed or handled they can inflict a painful sting. Male carpenter bees cannot sting but they often become aggressive and frighten people when they fly about their heads.

BIOLOGY AND HABITS

In the late spring and early summer, adult carpenter bees emerge from protected overwintering sites such as old nest galleries. These fertilized females soon begin boring into susceptible wood. After a gallery has been constructed, an egg is deposited with a mass of pollen and nectar. Then the egg with provisions is sealed off with a plug of wood pulp and saliva. The process is continued at the rate of one cell each day until approximately six cells are constructed. Adults then soon die. The larval period extends 30-45 days and the pupal period 14 days. Development form egg to adult requires 5 to 7 weeks or longer depending on temperatures.

CONTROL

There are at least three methods that could be used to control carpenter bees: 1. Aerosol treatments of insecticides applied directly to adult carpenter bees. 2. Residual surface and gallery treatments with insecticides and 3. Preventive treatments such as painting wood with thick coats of oil based or latex paints.

1. Aerosol insecticide sprays labeled for use to control flying insects and bees can be applied directly to carpenter bees. Care should be taken to prevent being stung. The oil based carrier and the insecticide will kill carpenter bees if applied directly to them. A few aerosols are available which have long range capabilities. These could be effective and safer to use than conventional aerosol sprays.

2. Residual applications of insecticides such as permethrin and cyfluthrin sprays can be applied to outdoor wooden surfaces which are being attacked by carpenter bees. An unsightly insecticide deposit could occur on treated wood so care should be taken. Nests or galleries can be treated directly with these insecticides or with others such as carbaryl or deltamethrin dusts that are labeled for carpenter bee control. Carpenter bees will be controlled when they contact the residual insecticide deposit.

Several days following treatment, after carpenter bee activity has ceased, holes can be plugged with dowel rods, plastic wood or with other suitable materials. If carpenter bees continue to attack the wood, additional residual insecticide treatments may be required at weekly or twice weekly intervals.

3. Wood which has been recently painted with oil based or latex paint will not normally be attacked by carpenter bees. Pressure treated wood is often resistant to attacks until it has weather for several years.

If you are looking for organic controls, there are only a couple of options which you can use. Boric acid can be used to control carpenter bees by placing this powder in the area or in the holes they make. Secondly, spraying pyrethrins can be effective, these chemicals are derived from chrysanthemums and are generally not considered to be dangerous.

Professional pest control operators can be especially helpful when carpenter bees are a problem. They are trained and equipped to handle carpenter bee infestations in even the most difficult to treat areas.

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Center Publication Number: 23

Source(s): Jacob G Price

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Virginia buttonweed is a low-growing, spreading weed that is difficult to control in lawn and landscape situations. It commonly grows in moist sites, such as woods and marshes, but can be especially troublesome in turfgrass areas.

 

Virginia Buttonweed Description:

A spreading perennial weed with slightly hairy, branched stems. Leaves are opposite and lance shaped. Opposite leaves are joined across the stem by a membrane. Virginia buttonweed has white tubular flowers with four lobes that are found at each leaf axil along the stem. This plant produces a green fruit that is elliptical, hairy and ridged and is also found at each leaf axil. Virginia buttonweed reproduces by seed as well as root and stem pieces. Leaves often turn mottled yellow in summer as a result of a virus.

Virginia Buttonweed Control in Turf:

Cultural:

If only a few plants are present, spot treat with Roundup or physically remove by digging. Remove all plant parts and soil, and replace with weed-free soil.

Post emergence:

Most herbicides only offer fair control(70-79%) and repeat applications are usually needed. Products containing 2,4-D, MCPP and dicamba, such as Weed-B-Gon and Weed Stop, are available at most garden centers and nurseries for use on bermuda, zoysia, centipede and fescue lawns. In centipedegrass and St. Augustine grass, premergence applications of atrazine (Bonus S) will help to control Virginia buttonweed plants that arise from seed, but will not effectively control plants that regrow from the roots. Always read the label when using herbicides and follow all ‘Directions for Use’ instructions. Refer to labels for specific rates for each type of grass. Be sure to keep these products away from nearby ornamental plants and do not re-seed or re-sod for at least 3 weeks. Virginia buttonweed flourishes in wet conditions; therefore, try to control excess water. Provide good drainage to areas infested with this weed.

Pre-emergence:

At this time, no pre-emergence controls have been effective.

Virginia Buttonweed Control in Ornamentals:

Roundup (glyphosate) provides good control(80-89%). Take special care to prevent drift of Roundup to nearby desirable plants and turf.

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Resource(s):

Georgia Turf
Weed Management

Center Publication Number: 96

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

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Young trees in the landscape, less than three to five years old, require special care to insure establishment and rapid growth. Proper early care helps young trees develop an adequate root system and a strong supportive branch structure. The time and expense invested to train a young tree is much less than treating problems as the tree matures.

Young trees may require staking, wrapping and corrective pruning. Proper mulching and control of competition can speed growth. In addition, trees require plenty of available water and essential elements for good growth. Young trees need protection from construction activities, lawn mowers and weed eaters, vandals, and pests.

Pruning

Young street and shade trees require proper pruning. Early pruning improves overall structure and corrects branch defects. Early pruning eliminates problems which become severe in middle and old age. Pruning shade and street trees develops and maintains a central dominant leader. Double or co-dominant leaders (forks) should be removed. Select the main leader early and maintain strong side branches. These side branches become the major limbs supporting the weight of the tree later in life. Remove dead, diseased and broken branches. Prune out deformed and crossing branches.

Many side branches should occur singly (alternately) on shade and street trees. However, trees such as ash and maple frequently have major branches occurring in pairs across the main stem. They can be pruned alternately up to 12 to 18 feet. Select and maintain major side branches spaced 24 to 36 inches apart on alternating sides of the stem. Also, select branches with wide angles of attachment, 60 to 90 degrees between the trunk and the branch. remove all waterspouts and basal sprouts.

Staking

Most established young trees can stand alone against wind and not be staked. Young trees with excessively long new shoots or those exposed to windy sites may require staking to remain upright. Stake young trees that are susceptible to blowing over. Anchorage staking holds the roots or root ball stationary until roots become anchored. Use two or three short stakes for anchorage. Extend stakes 12 to 18 inches above the ground. Loop one tie strap loosely around each stake and around the tree trunk. Low attachment prevents root ball dislodgement yet allows the top to move. Staking is temporary. Be sure to check ties frequently.

Support staking aids trees whose trunks are not strong enough to stand upright or fail to return upright. Support the top about six inches above the lowest level at which the trunk can be held and remain upright. This allows top flexibility while providing support. Support the trunk so it can flex without rubbing against the stakes or ties. This must not damage tender bark or girdle the expanding trunk. Support staking holds the tree upright until it can stand alone.

Wrapping

Newly-planted thin bark trees such as red maple or cherries may benefit from wrapping the trunks at planting. Thin barked trees planted on hot sites are very susceptible to sunscald. Commercial tree wraps or plastic tree guards will protect young trees. Spring planted trees can be susceptible to sunburn. The high temperatures from the summer sun may kill the cambium. Tree wraps insulate the cambium.

Young trees may require protection from sunscald. Sunscald occurs when the cambium of thin barked trees heats up during sunny fall or winter days. Colder temperatures that follow warm periods kill cambium cells in the trunk. Long vertical scars run down the trunk from near the lower most branches to the soil line. Injury usually occurs on the southwest side of the trunk. Thin bark maples and cherries, 4 to 5 inches in diameter, may require wrapping in fall to prevent sunscald.

Tree wraps also protect young trees from girdling by rodents. Start at the base of the trunk and wrap up to the lowermost limbs. Overlap each layer one-half inch. Wrap in the fall and leave the tree wrap on throughout the winter and early spring. Tree wrap is temporary and no longer needed once the tree develops corky bark.

Fertilization

Young trees growing in turf areas that are regularly fertilized do not usually require additional fertilization. Trees showing poor growth require a soil test to determine if essential elements are in short supply. When nitrogen is required, fertilize trees by applying 3 pounds of nitrogen per 1000 square feet of area per year. Make two or three applications, one each in April, June and October(optional) at 1 pound of nitrogen per 1000 square feet. Water each site after applying the fertilizer. Fertilizing trees with a turfgrass or groundcover understory requires multiple applications at light rates to avoid injury to the turfgrass or groundcover plants.

Mulching

Mulches aid in the establishment and growth of young trees. They conserve moisture by reducing evaporation from the soil surface. Mulches reduce erosion and water run-off. Mulches reduce competition and compaction. Mulches can effectively reduce summer soil temperatures to create a more favorable root environment. Organic mulches break down and add essential elements to the soil. Do not mulch wet sites, as mulch materials keep soils overly moist by retaining too much soil water.

To improve growth, mulch young trees out beyond the edge of the canopy. Use three to four inches of an organic mulch. Mulches eliminate the need for groundcovers and turfgrasses beneath young trees, thereby reducing competition for essential elements and moisture. Mulching prevents serious injuries to young tree trunks because there is no need to mow or use string-trimmers beneath trees.

Appropriate mulches include pine bark, pine straw and wood chips. Organic mulches more effectively insulate the soil than inorganic or rock mulches. Pull all mulches back from the trunk four to six inches to prevent diseases from invading the trunk. Rodents may live and burrow in loose mulches, so be alert for these pests.

Improving Growth

You can improve young tree growth by following a few basic cultural practices. First, eliminate competition from turfgrasses and groundcovers underneath young trees. Second, mulch beneath the canopy and out beyond the edge of the foliage to improve the root zone environment. Third, surface apply fertilizers directly to the mulched area. Fourth, water during periods of drought. Fifth, keep lawn mowers and string-trimmers away from tree trunks. These steps will improve growth, even on slow-growing trees.

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Resource(s):

• Landscape Plants for Georgia
• Native Plants for Georgia

Center Publication Number: 224

Source(s): Chris Starbuck, Woody Ornamental Horticulture, Cooperative Extension, University of Missouri.

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Mulching is one of the most important cultural practices to help new trees and shrubs get established and keep them healthy. Mulch conserves soil moisture, moderates soil temperature, reduces competition from roots of weeds and turf and generally facilitates penetration of water to the roots of woody plants. However, as the old saying goes, “too much of a good thing, is not a good thing.”

A common mulching practice now being used by some landscapers is to place mulch in a 2- to 3-foot diameter circle and 8 to 12 inches deep around newly-planted trees and shrubs. The mulch material is simply piled up and around the trunk to form a “volcano.” Although it may be said that a mulch volcano is generally better than no mulch at all, volcano-mulching can have serious negative effects on plant health. First, when mulch is placed more than about 4 inches deep, roots tend to “migrate” up into the mulch during rainy periods or when the area is irrigated. This is partly due to (temporarily) favorable root growth conditions in the mulch and partly to the suffocation of deep roots due to mulch-induced water-logging of the underlying soil. Then, when drought conditions occur, volcano-mulched plants may come under severe stress because many roots are growing in the mulch material which has considerably less water-holding capacity than real soil.

Another problem sometimes associated with mulch volcanoes that can kill new trees is the “umbrella” effect. The surfaces of mulch volcanoes around shrubs and trees can become hydrophobic due to fungal activity and act very effectively as umbrellas, shedding water to the surrounding area. This is more common in high carbon mulches like ground wood, wood chips or sawdust, but it can also occur in bark mulches. It should be kept firmly in mind that until a newly-planted tree can grow roots out of the original soil ball and into the surrounding soil, the tree is absolutely dependent on moisture in the original ball. If the soil ball is kept dry by a mulch umbrella/volcano, the tree will suffer severe drought stress during the establishment period.

Other possible problems associated with mulch volcanoes include: the promotion of fungal canker diseases caused by the presense of constant moisture around the lower trunk; stress from poor gas exchange by the cells in the bark that results in bark decay; and damage from termites and rodents that may make take up residence in the volcano.

When deciding on the best approach for mulching trees and shrubs in the landscape, go for a walk in the woods to see how Mother Nature does it. Trees in their native habitats rarely have individual mulch rings. Plants tend to share a large common soil volume that is nicely mulched by decomposing leaves that are releasing minerals to the soil. Also, the mulch layer is rarely more than 2 inches thick and never in the form of a volcano

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Center Publication Number: 219

Source(s):

• Nancy Doubrava, HGIC Information Specialist, Clemson University.
• Bob Polomski, Extension Consumer Horticulturist.

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The poinsettia (Euphorbia pulcherrima) is the most popular flowering plant sold in the United States with more than 70 million sold nationwide each year. When South Carolinian Joel Poinsett, the first U.S. ambassador to Mexico, introduced the poinsettia to the U.S. in 1825, it’s doubtful he had any idea how popular this plant would become.

Plant breeders have produced cultivars with many other colors besides the traditional red bracts, or modified leaves. Plants are available with white, pink, peach, yellow, marbled and speckled bracts. The actual flowers of the poinsettia plant are the small, yellow blossoms in the center of the colorful bracts.

KEEP YOUR POINSETTIA BEAUTIFUL

To help your poinsettia thrive in your home during the holiday season, follow these tips:

Light: Set your poinsettia in a bright location so that it receives at least 6 hours of bright, indirect sunlight each day. Putting it in direct sunlight may fade the color of the bracts. If direct sun cannot be avoided, filter the sunlight with a light shade or sheer curtain.

Temperature: Excess heat will cause the leaves to yellow and fall off and the flower bracts to fade early. The daytime temperature should not exceed 70 °F. Do not put your poinsettia near drafts, excessive heat or dry air from appliances, fireplaces or ventilating ducts. Chilling injury is also a problem and can cause premature leaf drop if the temperature drops below 50 °F.

Water and Fertilizer: Poinsettias require moderately moist soil. Water them thoroughly when the soil surface feels dry to the touch. Never let the potting mixture completely dry out and never let the plant sit in standing water. When watering, always take the plant out of its decorative pot cover. Water until water seeps out of the drainage hole and the soil is completely saturated. Do not fertilize a poinsettia when it is in bloom.

CARE AFTER THE HOLIDAY SEASON

Around March to April, when the colorful bracts fade, prune the plant back to about 8 inches in height. Although the plant will look bare after pruning, eventually new growth will emerge from the nodes up and down the stem. Keep the plant near a sunny window and continue to water it regularly during its growing period. You can take the plant outdoors once the night temperature remains above 50 °F. Fertilize the plant every two to three weeks during the spring, summer and fall with a well-balanced complete fertilizer such as 10-10-10.

In early June, transplant the poinsettia into a container 2 to 4 inches bigger than the original pot. Use a soil mix containing a considerable amount of organic matter, such as compost, leaf mold or peat moss. Pinch back the shoot tips or prune back the branches. Do not pinch back after September 1. When night temperatures become cool, 55 to 60 °F, bring the plant indoors to a sunny location.

REFLOWERING A POINSETTIA

Poinsettia plants can be brought back into flower next year, although this procedure is somewhat demanding. Poinsettia is a short-day plant, which means it needs a continuous long dark period each night to form its colorful bracts. Starting the first week of October (for an eight- to 10-week period) the plant must be kept in total darkness for 14 continuous hours each night. Keep the plant in darkness by moving it to a closet or covering it with a large box. During this period, the plant must also receive six to eight hours of bright sunlight daily. Depending on the response time of the particular cultivar, the plant will come into full bloom during November or December.

PROBLEMS

Pests that attack poinsettias are also common to many other plants. The most common insect pest is the whitefly. Other pests of poinsettia include mealybugs, soft scales and spider mites. Root rotting fungi can occur in overwatered or poorly drained soils. Several factors can cause premature leaf drop, such as temperatures dropping below 50 °F, poor light or poor nutrition. Keep the delicate colorful bracts well-protected from wind and cold rain.

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Center Publication Number: 158

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

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Just like trees, shrubs, pets and even humans, turf grasses need water to survive. The perception that turf is a water consumer is correct, but we’re all water consumers.

The forgotten benefits

Often forgotten are the environmental benefits of a healthy turf. Grass prevents soil erosion, filters rainwater, traps airborne dust and soot and acts as a noise abatement. Imagine how much louder our lives would be without turf to absorb the polluting sounds of the fast-paced world.

Lawns can act as air conditioners, too. The surface temperature of an actively growing turf grass may be 20 degrees (Fahrenheit) cooler than a dormant turf. As a result, the surroundings are cooler, too, so it costs less to cool buildings.
Don’t forget that grass is a plant. So, through photosynthesis, it converts carbon dioxide to oxygen — which we all require.

Choose and plant appropriately

Many inputs are needed to maintain a healthy turf, but proper water management is the most important. For best water conservation, choose and plant the right grass.

Different types of grasses are better adapted for particular climates. Properly matching the grass with the climate minimizes its water requirements. Georgians are fortunate to have a diversity of climates and an array of turf species to choose from.
Likewise, plan to establish a new lawn at the right time. Trying to plant a lawn just as the climate gets its toughest takes more water and money. Work with nature, not against it.

Water wisely

Once the lawn is actively growing, water wisely. Most turf grasses grown in Georgia need about 1 inch of water per week to maintain normal growth and color. Base their watering on need, not on the day of the week.
Watch for signs of moisture stress, such as wilt, leaf blades rolling or the turf’s failure to bounce back from foot traffic. The right time to irrigate is when you first see signs of stress.

Water, though, with the idea of watering deeply but not often. Light, frequent irrigations lead to shallow, weak root systems that require more money and effort.

Turf roots will “mine” for water. As the soil surface dries, roots explore greater soil depths in search of moisture. Allowing the turf grass a little moisture stress can actually increase rooting depths and, in the long run, save water.
Typically, you should apply one-half to 1 inch of water at a time, depending on the soil.
Pay attention. Avoid watering so much that the soil becomes saturated and water runs off the soil surface. If the water doesn’t make it to the turf’s root zone, it’s of little use to the plant.

Don’t water the pavement, either. Many have tried, and adding water doesn’t cause the asphalt or concrete to grow.
Watering is most efficient in the early morning, when losses from evaporation are less. Research shows that water losses at night are 50 percent less than in midday irrigation. Once again, the plant can use only water in the root zone. Water vapor can’t help the grass at all.

Get help, if you need it

For further help with turf topics, consult your local county agent of the UGA Extension Service. Turf can be a valuable asset to the landscape and the environment, but it’s up to us to properly manage water resources.
Turf grasses don’t waste water. People do.

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Resource(s):

Lawns in Georgia

Center Publication Number: 151

Source(s): Gil Landry, PhD., Coordinator – UGA Center for Urban Agriculture, The University of Georgia.

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Proper watering of turfgrasses is essential to producing an attractive, healthy lawn.

Many factors influence the amount and frequency of water needed for a home lawn. Soil type, type of grass, management level, frequency of rain, temperatures, wind and humidity all affect the amount of water needed. High level maintenance and hot, windy days tend to increase the demand for water, while low level maintenance and cool, cloudy days tend to decrease the demand for water.

The best time to apply water is just before wilt occurs. Most grasses appear a dull bluish green, the leaf blades begin to fold or roll, and footprints remain after walking over the area when the grass is under water stress. If dry conditions continue, the grass wilts. Begin irrigation on that portion of the lawn which first exhibits these signs.

Apply enough water to soak the soil to a depth of 6 to 8 inches. This is usually equivalent to about one inch of rainfall. For most sprinklers, this means leaving the sprinkler in one spot for 2 to 3 hours. Do not apply until runoff occurs. If water is being applied faster than the soil can absorb it, either move the sprinkler to a new location or turn it off and allow the existing moisture to soak into the soil. To test your sprinkler output, place seven open-top tin cans under the sprinkler.

Prior to sunrise is considered the best time to water because of less wind and lower temperature. Research indicates water losses at night through irrigation are 50 percent less than during midday irrigation. Studies also indicate that irrigating after dew develops on a turf will not increase disease problems. However, irrigating prior to dew formation or after the dew has dried from the morning sun and/or wind extends the period of free surface moisture and may enhance disease development.

Irrigation is one maintenance practice often done wrong. Light, frequent waterings produce shallow, weak root systems. The shallow root system prevents efficient use of plant nutrients and soil moisture. Roots grow only where the soil is moist; they do not seek out water.

The key to success in irrigating home lawns is to condition the grass to get by on as little extra water as possible. The best way to do this is to develop a deep rooted grass. Listed below are several simple rules which will help develop a deep rooted turfgrass which is more able to withstand drought conditions.

• Select a grass which is well adapted to your locations.
• Water as infrequently as possible. At the first sign of wilt, irrigate, not before.
• Apply enough moisture to drench the soil 6 to 8 inches deep.
• If the soil becomes compacted or crusted, loosen it so that water can penetrate to the proper depth.
• Raise the height of cut during stress periods, and mow more frequently.
• Use a sprinkler that gives a good even distribution of water at about 1/4 to 1/3 inch per hour.
• Fertilize lightly in the summer months.

For more information refer to Cooperative Extension Leaflet No. 399, Turfgrass Water Management.

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Resource(s):
Lawns in Georgia

Center Publication Number: 133

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

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Water is the single most limiting essential resource for tree survival and growth. Water shortages severely damage young and old trees alike, and set up healthy trees for other problems. Drought conditions can lead to tree decline, disease and insect problems and non-recoverable damage. Supplemental watering can greatly assist in maintaining tree health during droughts – both during the growing season or during the dormant season.

How To Water

The best ways to water trees are by soaker hose or drip irrigation. Automated lawn sprinklers are less efficient for applying water to trees than soaker hoses or drip irrigation. Even a garden hose, moved often, can provide a good soil soaking. Use a light organic mulch to conserve moisture and apply water over the top of the mulch. Do not allow water to concentrate at the base of the trunk as this can lead to pest problems.

Where To Water

Most of the tree’s absorbing roots are in the top foot of soil. Applying water deeper than this level misses the active roots and allows water to drain away, wasting efforts and water. Apply water across the soil surface and let it soak into the soil. Surface soaking allows tree roots more chances to absorb any water and helps maintain soil health.

Lay-out water hoses or applicators out to the tree crown edge (drip-line). Try to water the soil areas directly beneath the foliage and shaded by the tree. Do not water beyond the drip-line and do not water closer than 3 feet to the trunk base on established trees. Be sure the water soaks into the soil. Use mulch and slow application rates on slopes, heavy soils (clays), and compacted soils to assure water is soaking-in and not running-off. If the tree is surrounded with other landscape plants, or by turf, deep soaking applications will benefit all. Do not spray tree foliage when applying water. Water droplets on tree leaves can lead to pest problems and destruction of leaf tissue through sun damage. Try not to wet the trunk if possible. Young, newly planted trees need additional watering care. Water has limited horizontal movement in soil. You must apply water directly over where you need it in the soil. For new trees, concentrate water over the root ball, as well as the planting area, to assure survival.

Old, large trees can be extensively watered over the entire area under their foliage. Another method in watering large trees is to select roughly 1/3 of the area within the drip-line for concentrated water applications.

When To Water

The best time to water is at night from 9 p.m. to 9 a.m. Trees refill over the nighttime hours. Watering at night allows effective use of applied water and less evaporative loss, assuring more water moves into the soil and tree.

Because trees lose water from day-to-day, month-to-month, and season to season – dormant season watering during winter drought is important, especially for evergreen trees and juvenile hardwood trees that have not lost their leaves. Because of temperature and relative humidity interactions, much less water is required in the dormant season, but water is still needed. Do not water when the soil surface is less than 40°F.

For every 18°F increase in temperature, the amount of water lost by a tree and the site around it almost doubles. This feature of water loss must be factored into applying supplemental water to a tree. Trees surrounded by pavement and other hot, hard surfaces can be 20-30°F warmer than a tree in a protected, landscaped backyard. Water use rapidly climbs with increasing temperatures, and so should water application volumes.

How Much To Water

Depending upon soil texture 1 to 2 inches of water per week should keep a tree healthy. Trees in limited rooting areas, in containers or pots, or on major slopes, need additional care to assure water is reaching the root system in adequate amounts and not suffocating roots from lack of drainage. Five gallons per square yard is about 1 inch of water.

Fine soils (clays) require careful attention to prevent over-watering and root death. Sandy soils can be severely droughty because water runs out of the rooting zone quickly. Composted organic material additions and organic mulch covers on the soil surface can help hold and prevent rapid loss of applied water.

How Often To Water

Trees should be watered once or twice a week (minimum of 1 inch per watering)in the growing season if there is no rainfall in that particular week. A few heavy waterings are much better than many light, shallow waterings. A greater proportion of the applied water is utilized by the tree with heavy watering. Also, light waterings encourage shallow rooting which can lead to more severe drought damage. Once you begin watering you should continue to water until rain comes.

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Center Publication Number: 220

Source(s): Willie Chance, UGA Extension Agent, Houston County.

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Live Holiday gift plants require care to bloom and maintain health.

Poinsettias need a daytime temperature of 65 to70 degrees Fahrenheit. Reduce this to low 60’s at night. Put poinsettias in bright light but never in full sun. Select areas where the plant will not dry out. If placed in a window, remove it at night so it will not get too cold. Let the soil surface dry slightly between waterings and then water until it runs out of the bottom of the pot.

Poinsettias are very sensitive to environment. Drafts, cold, heat, dim light, low humidity or improper watering may cause these plants to wilt or shed leaves and flowers.

Amaryllis require bright light, cool conditions and moist soils like other flowering plants. Bulbs bloom four to six weeks after planting. Individual flowers last three to four days but a plant may have two flower stalks with three to four flowers per stalk.

To re-bloom an amaryllis, let the leaves grow normally in a well-lit warm location. Put them outside in the spring and summer. Fertilize and water as needed. Once leaves begin to die back, slowly and eventually stop watering. Store the bulb in a cool, dry place for four to eight weeks before beginning growth again by watering.

Holiday Cacti come in three types which bloom at different times of the year. Depending on type, they flower at Thanksgiving, Christmas or Easter. All three require bright light, well-drained soils and moderate moisture levels. South facing windows are good places for holiday cacti. After bloom, remove faded flowers and fertilize. They can be grown outside in spring and summer in shady locations. Stem pieces of three segments or more root easily.

Holiday cacti flower based on day length and temperature so they should bloom at the same time every year. Strong artificial lighting and high temperatures can delay or prevent bloom. You may need to restrict very bright artificial lights at night during the time of blossom development (September and October for Thanksgiving and Christmas Cacti or February and March for Easter Cacti). Thanksgiving and Christmas cacti need 12 to 14 hours of uninterrupted dark during the night for about six weeks to develop blooms. During bloom development keep temperatures cool – 55 to 65 degrees at night and 5 to 10 degrees higher in the day. Keep the plants slightly on the dry side. Return slowly to normal watering after flower buds develop. Sudden changes in environment may cause the plant to shed flower buds.

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Reviewer(s):

• Allison Perkins, Bartow County Agent, The University of Georgia.
• Paul Pugliese, Cherokee County Agent, The University of Georgia.
• Mary Carol Sheffield, Paulding County Agent, The University of Georgia.

Center Publication Number: 229