Pruning

Spring Bleeding: Maple, Birch, Elm, Grapevines

by

Following a late winter or early spring pruning of Maple, Birch, Elm, or Grapevines it is common to observe “bleeding” from the pruning wounds.  This phenomenon usually occurs just before and during leaf emergence in the spring, especially during years of abundant soil moisture.  The temporary bleeding is generally not detrimental to the health of the plant and primarily consists of a watery sap solution. The bleeding usually ceases once the leaves have fully emerged and water begins to evaporate through the leaf stomata, creating transpirational pull that overshadows the root pressure.

The upward flow of water is caused by osmotic pressure in the root system that begins with the imbalance of water molecules between the soil and the root system.  A high concentration of minerals and carbohydrates in the root system generally translates to a lower concentration of water molecules when compared to the surrounding soil. Water molecules enter the root cells to equalize distribution, causing root cells to become turgid and force water upwards in the vascular system.  (Incidentally, the reverse is true when too much fertilizer is applied and a higher concentration of minerals in the soil prevents the osmotic absorption of water into the root system.)

Occasionally, bleeding can be a nuisance where these plants drip on parked cars and pedestrian spaces.  In such cases, delay pruning of these species until late spring-early summer to help to reduce the issue.

If prolonged bleeding occurs and you observe any unusual signs or symptoms of pests or disease, report the information to your local extension agent for further assessment.

Prune liriope and pampus grass in late winter

by

liriope MSWTwo ornamental plants in the landscape that are commonly sheared are liriope and ornamental grasses such as pampas grass. Shearing in late winter removes old growth and makes way for new shoots.

Liriope

Annual removal of liriope foliage is not a necessity; however, cutting back is desirable if severe winter injury to the foliage has occurred. Running a lawn mower over the plants is a practical means of removal. Hedge shears may be a more practical means for large individual clumps.

In Georgia, new growth often begins to emerge in February and March; therefore, prune earlier or plan to cut back high to prevent injury to the new shoots.

Severely pruning mondo grass (Ophiopogon japonicus) is not recommended.
Severely pruning mondo grass (Ophiopogon japonicus) is not recommended.

Mondo grass (also called monkeygrass or Ophiopogon) redevelops slowly after severe pruning. Do not shear these plants.

Homeowners and maintenance personnel often neglect fertilizing lilyturf and thus do not obtain maximum vigor. A broadcast application of a general lawn or shrub fertilizer in early spring and again in mid-summer should be adequate to maintain the desired vigor.

Dwarf pampas grass Image - Jeff Webb
Dwarf pampas grass Image – Jeff Webb

Pampus grass

Prune pampas grass annually to remove the previous year’s foliage and make way for new growth.  Pruning is best done in late winter, prior to the new growing season. Use hedge shears, lopping shears or power pruners to cut the plant back close to ground level. Be sure to wear a long-sleeve shirt and gloves when pruning to protect yourself from the sharp leaf blades.

After pruning pampas grass, apply a light, broadcast application of a complete fertilizer, like 8-8-8 or 10-10-10, to help stimulate new growth.

This is edited from these publications – where you can find more information.

Liriope Culture in Georgia 

Pampas Grass

Care of Ornamental Plants in the Landscape

When should we prune azaleas & crape myrtles (and other plants!)

by

Prune spring blooming azaleas after they bloom and crape myrtles in late winter before growth begins.

Info edited from Pruning ornamental plants in the landscape

Because flowering ornamentals form their flower buds at different times of year, pruning times must be adjusted accordingly. Many spring-flowering plants such as azalea, dogwood, forsythia, redbud and rhododendron set flower buds in the fall, so pruning during the fall or winter months eliminates or decreases their spring flower display. Plants that typically flower during the summer form flower buds on new growth and can be pruned during the winter with no effect on their flowering. Examples of this type of plant are crape myrtle and abelia.

As a general rule, plants that flower before May should be pruned after they bloom, while those that flower after May are considered summer-flowering and can be pruned just prior to spring growth. One exception to this rule is the oakleaf hydrangea, a summer-flowering shrub that forms flower buds the previous season. Another exception is late-flowering azalea cultivars, which bloom during May, June or even July. Prune both the oakleaf hydrangea and the azalea cultivars after they bloom. Table 1 provides suggested pruning times for other plants.

Table 1. Suggested Pruning Time for Common Flowering Trees, Shrubs and Vines

Prune after Flowering
Azalea Japanese Pieris
Beautybush Lilac
Bigleaf hydrangea Mockorange
Bradford Pear Oakleaf hydrangea
Bridalwreath Spirea Pearlbush
Clematis Pyracantha
Climbing roses Redbud
Crabapple Saucer Magnolia
Deutzia Star Magnolia
Dogwood Shrub Honeysuckle
Doublefile Vibernum Thunberg Spirea
Flowering Almond Vanhoutte Spirea
Flowering Cherry Weigelia
Flowering Quince Winter Daphne
Forsythia Wisteria
Japanese Kerria Witchhazel

Prune before Spring Growth Begins
Beautyberry Goldenrain Tree
Camellia Japanese Barberry
Chaste Tree (Vitex) Japanese Spirea
Cranberrybush Viburnum Mimosa
Crape myrtle Nandina
Floribunda roses Rose-of-Sharon (Althea)
Frangrant Tea Olive Sourwood
Grandiflora roses Anthony Waterer Spirea
Glossy Abelia Sweetshrub
Hedges

Ornamental plants that are not grown for their showy flowers can be pruned during the late winter, spring or summer months. Avoid pruning during the fall or early winter because it may encourage tender new growth that is not sufficiently hardened to resist the winter cold.

Some shade and flowering trees tend to bleed or excrete large amounts of sap from pruning wounds. Among these trees are maple, birch, dogwood, beech, elm, willow, flowering plum and flowering cherry. Sap excreted from the tree is not harmful, but it is unsightly. To minimize bleeding, prune these trees after the leaves have matured. Leaves use plant sap when they expand, and the tree excretes less sap from the wound.

For more information, see the publication Pruning ornamental plants in the landscape.

Begin shaping trees while they are young

by

This info edited from Pruning ornamental plants in the landscape

Pruning deciduous trees (trees that lose their leaves in the winter)

Trees are like children; training at an early age will influence how they develop. Many people are reluctant to prune a young tree, particularly when it is nothing more than a single stem or a few scrawny branches, but this is precisely when pruning should begin.

Ideally, deciduous shade trees (those that lose their leaves during the winter) and flowering trees should have one central trunk (leader) and five to eight strong lateral branches along the main trunk. Major limbs should begin about 5 feet above the ground and have good spacing around the main trunk.

Once the framework (trunk and main branches) of the tree is established, some annual maintenance pruning will be required. Each tree is different in its growth habit, vigor and pruning requirements, but there are some general considerations that may help direct your pruning decisions:

  • A major limb growing at a narrow angle to the main trunk (less than a 45-degree angle) is likely to develop a weak crotch and may split during heavy winds and ice loads. Remove branches that have narrow crotch angles.
  • Remove branches that grow inward or threaten to rub against nearby branches (Figure 10).
Figure 10. Remove suckers originating from below-ground roots (a), low-growing branches that interfere with maintenance (b), upright growing shoots or watersprouts (c), branches that grow inward or rub other branches (d), and branches that compete with the central leader for dominance (e).
Figure 10. Remove suckers originating from below-ground roots (a), low-growing branches that interfere with maintenance (b), upright growing shoots or watersprouts (c), branches that grow inward or rub other branches (d), and branches that compete with the central leader for dominance (e).
  • Remove branches that grow downward from the main limbs which may interfere with mowing and other maintenance practices.
  • Prune branches damaged by insects, diseases, winter cold or storms below the damaged area. Prune branches of pear, pyracantha or loquat damaged by fireblight disease several inches below the infection. To prevent spreading the disease, sterilize pruning tools between cuts by dipping the blades in rubbing alcohol or a solution prepared from one part house-hold bleach to 10 parts water.
  • Trees such as Bradford pear, ornamental cherry, crabapple and ornamental plum form vigorous shoots (or suckers) at the base of the trunk and many upright succulent shoots (or watersprouts) along the main branches. These shoots starve the tree of valuable nutrients and detract from the tree’s overall appearance. Remove them while they are young.

Some trees develop upright shoots that compete with the main trunk for dominance. Remove these shoots if you want to maintain a conical or pyramidal growth habit.

Magnolia
Pruning evergreen trees

Broadleaf evergreens, like magnolias and hollies, usually require little or no pruning. In fact, most develop a naturally symmetric growth habit when left alone. Low-sweeping branches at ground level lend a natural southern charm to our landscapes.

You may want to prune some during the early life of the tree to balance the growth or to eliminate multiple trunks and/or multiple leader branches. Otherwise, routine annual pruning is not recommended.

For more information see Pruning ornamental plants in the landscape