Month: September 2013

Source(s): Jim Midcap, Extension Horticulturist, The University of Georgia

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The hydrangeas we know best in Georgia are the garden shrubs which produce fluffy blue flower globes during summer.

We also see them in florists’ pots, blooming in rich shades of pink or blue – until we plant them in our gardens. Then they flower in a sickly blend of the two colors or not at all.

Let’s look at ways we can help that familiar “mophead” or “florists”‘ hydrangea look its best and let’s learn about its wonderful relatives, the other hydrangeas for our landscape.

Hydrangea macrophylla

Hydrangea macrophylla is the botanical name for bigleaf hydrangea. There are two distinct types of bigleaf hydrangea: the “hortensia” (mophead,florists’, French and Japanese are some of its nicknames) and the “lacecap”, so-called because of the disc-like blooms that have tight little fertile flowers in the center and showier sterile flowers around the outer edge.

Bigleaf hydrangea blooms may be blue, pink or white, depending upon plant variety and soil acidity. This plant can absorb more aluminum from acidic (pH 5.0-5.5) soil. Aluminum contributes to rich blue flowering. Less aluminum can be absorbed by a plant growing in more alkaline (pH 6.0-6.5) soil. A deeper pink flower is the result. Color can be intensified as follows:

Make blue-flowering varieties or cultivars bluer over time by watering in 1/2 cup wettable sulfur powder per 10 square feet once a year OR, more quickly, by applying one tablespoon of aluminum sulfate in a gallon of water around the plant in March and again in April and May.

Pink varieties or cultivars develop richer color if you apply one cup of granular dolomitic lime per 10 square feet once a year OR if you drench around the plant with one tablespoon hydrated lime powder in a gallon of water in March, April and May.

Plant bigleaf hydrangea in partial shade, only as deeply as it grew in the pot or previous location, working lots of organic matter into a wide hole. Keep the plant evenly moist but do not fertilize during the first month or two. Afternoon shade and good mulching help to keep the leaves from drooping in summer heat.

Fertilize in March, May and July with one pound (2 cups) of 8-8-8 or 10-10-10 granular fertilizer per 100 square feet and water deeply as needed. Hydrangeas are very hungry, thirsty plants. An acid forming fertilizer would be best for blue varieties, an alkaline fertilizer for pink ones.

Prune bigleaf hydrangeas to control size as blooms fade, usually before August 1, because next year’s buds begin forming during late summer. Pruning in spring removes potential blossoms. If you choose to let the shrub reach its natural size and shape, you may prune for increased vigor by cutting out old woody stalks to the ground in-late winter.

Protect developing flower buds from late freezes which sometimes destroy a year’s flowering. Patio pots of small varieties can be moved to shelter during extreme cold. Large plants may be covered with sheets or blankets, but these should be removed during sunshine or the plant may be scorched.

Blooms usually appear during June and July in the Atlanta area. Cutting them for indoor use or drying encourages more bloom. Dry the blossoms by hanging in a dry, warm location or by putting them in a vase with only an inch or so of water and ignoring them until they are dried.

Varieties of Hydrangea macrophylla (bigleaf hydrangea) are endless, but many are available only from specialty nurseries. Here are a few good ones to look for:

Hortensias (Mopheads)

• ‘Nikko Blue’ – the standard blue mophead, grows to 6′, heavy bloom, needs acid soil
• ‘Otaska’ – rich blue in acid soil, to 3′ tall, bends under weight of blossoms
• ‘Forever Pink’ – needs lime here for richest color, compact 3′ tall, good dark green foliage, early June bloom
• ‘Pia’ – very small (1′) for rock garden or mixed border, reddish-purple bloom in any soil acidity
• ‘Sister Therese’ – small, white bloom, good for containers

Lacecaps

• ‘Variegata’ – nice white-edged light green foliage, blue disc flower in acid soil, 3′ tall
• ‘Lanarth White’ – to 3′, mostly white bloom with touches of blue or pink in July/August, perhaps the best lacecap
• ‘Blue Wave’ – rich blue in acid soil, to 7′ tall.

Hydrangea serrata

Hydrangea serrata, named for its serrated leaf edges, is very much like the lacecap bigleaf hydrangea. Being a mountain woodland native, it is more cold-hardy. Treat it like the big leaf and try these cultivars:

• ‘Bluebird’ – grows to 5′, resists drought, June flowers may be coaxed to blue or pink
• ‘Preziosa’ – to 4′, flowers emerge pink, deepen to crimson, sun or part shade, red fall foliage

Hydrangea arborescens

Hydrangea arborescens is called “hills of snow” because of its broadly rounded, showy white blooms or “smooth hydrangea” because of its bark appearance. These plants are striking when grouped in natural-looking masses under trees.
Plant this southeastern native in moist, partly shaded, rich soil.

Fertilize well in late winter with 10-10-10 (2 cups per 100 square feet), mulch to retain moisture, water during dry spells.
Prune this kind of hydrangea in late winter before new growth begins, for H. arborescens blooms on the new growth of the season. To restrict size cut the whole plant to 12″ in height. Otherwise remove the oldest stems to the ground and tip-prune the vigorous young ones.

Blooms appear in June/July. Another flowering in August/September may occur if old flowers are removed after completing their bloom.

Cultivar ‘Annabelle’ is the only one recommended. It grows 3′ to 5′ tall, 4′ to 6′ wide, and has gorgeous flower mounds up to a foot across. The blooms emerge apple green, become white, then revert to green before browning. Fall foliage is sometimes yellow. ‘Annabelle’ has been chosen as a 1995 Georgia Gold Medal Plant because of its outstanding flower and growth characteristics.

Hydrangea paniculata

Hydrangea paniculata is a large (10′ to 15′) shrub commonly seen in the colder northeast where its white panicles (cone shaped blossoms) fade to an old rose in early autumn. It also grows vigorously in our area – in fact it is hard to kill.
Plant in moist, loamy soil either in sun or part shade.

Prune in late winter (blooms appear on the new season’s growth) by cutting back hard to control size or by removing all but 5 to 10 vertical stems on which new, vigorous shoots will grow and flower.

Fertilize heavily in April and June with a cup or two of 10-10 10 per plant.

Cultivars include:

• `Grandiflora’ – usually called “PeeGee” (short for Paniculata Grandiflora, has cones of bloom 12″ to 18″ long and 6″ to 12″ wide at base during late summer
• `Praecox’ – blooms in June
• ‘Tardiva’ – smaller flowers in September, good for cutting

Hydrangea quercifolia

Hydrangea quercifolia, the “oakleaf hydrangea”, gets its name from the shape of its leaf. A southern native, the species is often seen in older gardens where it suckers from it roots to form wide colonies in moist, shady areas. This plant is remarkable for rich red and bronze fall color and for attractive peeling bark in winter.

Plant in moist, semi-shady, rich soil where a rather casual, woodsy appearance is appropriate. Good drainage is needed.

Fertilize with 8-8-8 or 10-10-10 in spring and summer, one pound per 100 square feet, and keep evenly moist.

Blooms are cone-shaped white, aging to rose and then brown, appearing in early summer. They arise from buds set at the end of the previous summer.

Prune around August 1 as blooms fade. Cut out old canes to promote new growth.

Cultivars represent a big improvement over the species:

• `Snow Queen’ – flowers mature to a good pink, foliage dark green, withstands sun well, holds flower spikes upright
• `Snowflake’ – prefers partial shade, the many large blooms have a double-flowered appearance, probably the best oakleaf
• ‘PeeWee’ – a 2′ to 3′ cultivar, good choice for smaller gardens or mixed borders

Hydrangea petiolaris

Hydrangea petiolaris, the climbing hydrangea, is an unusual and uncommonly good vine or groundcover for our area. Deep green leaves turn bright yellow in autumn and then drop to reveal the tracery of peeling bark throughout the winter.

Like ivy this vine clings with root-like holdfasts and so should be planted only against masonry walls or very sturdy trellises. It is effective tumbling over a rock wall or climbing a large tree, where it may grow to 60′ or 80′. Climbing hydrangea grows in a mounded, three-dimensional habit, unlike other vines that lie close to the surfaces they cover.

Plant in a moist, semi-shady area with rich, well-drained soil. Very cold-hardy, it suits a northern or eastern exposure well. After a year or two of slow root establishment, it should grow rapidly.

Fertilize in spring if you wish with a balanced complete fertilizer such as 10-10-10 and keep evenly moist.

Blooms are of the white lacecap type, occurring in June or July on old wood. Heavy shade may reduce the number of flowers, but this plant is worth growing for foliage and bark alone.

Prune only as necessary to keep in bounds.

Schizophragma hydrangeoides

Schizophragma hydrangeoides, Japanese hydrangea vine, is quite similar to climbing hydrangea. This vine has more deeply serrated leaves, lies flat against the surface it climbs and blooms a little later. Site and culture needs are the same as for H. petiolaris.

There is a rose-tinged cultivar called ‘Roseum’, while ‘Moonlight’ has silvery green leaves and white lacecap blooms.

Sources for Out of the Ordinary Hydrangeas

• Louisiana Nursery, Rt. 7, Box 43, Opelousas, LA 70570
  • (318) 948-3696
  • Catalogue $5, refundable with purchase
• Wayside Gardens, 1 Garden Lane, Hodges, SC 29695-0001
  • 1-800-845-1124
• Wilkerson Mill Gardens, 9595 Wilkerson Mill Rd., Palmetto, Ga 30268
  • (404) 463-9717
  • Phone for extensive list of varieties and direction

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Center Publication Number: 76

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

 

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Trees across Georgia are declining due to drought. Drought stressed trees may have fewer or smaller leaves. Small or large limbs or the entire tree may die. Although trees can withstand some drought injury, some trees may require months to years to recover. Trees may not show damage immediately. When they do, it may be too late to save them. Protect trees now from drought with proper care.

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. 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 pile mulch against the base of the tree or 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 misses the active roots and wastes water.

Lay-out water hoses or applicators out to the tree crown edge (drip-line). 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 4 feet to the trunk base on established trees.
Use mulch and slow application rates on slopes, heavy soils (clays), and compacted soils to assure water is soaking-in and not running-off. Do not spray tree foliage when applying water. Water droplets on tree leaves can lead to pest problems. Try not to wet the tree’s trunk.

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

When to Water

The best time to water is at night from 10 p.m. to 6 a.m. Trees refill with water during the night. Watering at night reduces losses to evaporation and assures that more water moves into the soil and tree.

For every 18°F increase in temperature, the amount of water lost by a tree and the site around it almost doubles. Consider this when watering trees. 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 sustain a tree. 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 dry out rapidly since water runs out of the rooting zone quickly. Composted organic mulch on the soil surface can help prevent rapid loss of applied water.

How Often To Water

Water trees 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 used by the tree with heavy, infrequent watering. Once you begin watering, continue to water until rain comes.
Drought is the main cause of tree decline but beware of other factors that damage roots and lead to long-term tree decline and death.

• Do not fertilize or use pesticides on severely drought stressed trees.
• Do not dig or drive under the canopy of trees or do other things that kill or crush roots.
• Do not pile soil under tree canopies. When adding soil to cover roots etc., add no more than 1 inch per growing season. Protect the critical root zone of the tree. Measure the trunk diameter at chest height in inches. Multiply this by one and a half. This will be the size in feet of the radius of the circle that you must protect around the tree. For instance, a 20 inch diameter tree would have a critical root zone with a radius of 30 feet. Avoid digging, piling soil, trenching or driving through this area.

Call your local Extension Agent at (800-ASK-UGA1) or Locate your local Extension Office Georgia Extension Office Locations

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Center Publication Number: 267

Source(s):

• Lynwood Blackmon
• Ellen Bauske

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Pruning and training are important practices for managing fruit trees. The primary objective of pruning and training is to develop a strong tree framework that will support fruit production. All fruit trees are not pruned and/or trained in the same fashion. This publication is designed to get a new tree started correctly and will cover pruning and training in the first year only. It is not comprehensive. Visit UGA Cooperative Extension’s web site (http://www. caes.uga.edu/Publications/subjectList.cfm) and find the publication on your specific tree. For example, search home garden figs, apples, blueberries etc. These publications contain up-to-date, research-based information.

The proper time to prune is during late winter and early spring before new growth occurs. During this time, pruning wounds heal quickly, flower buds and undesirable branches are easily recognized, bark is less likely to tear when cuts are made, and injury from low winter temperatures is avoided. Light summer pruning may also be used to train young trees to the desired shape, improve light quality, thin fruit loads or remove water sprouts and other undesirable growth.

Apple, Pear, Plum and Apricot

These trees are pruned and trained to a central leader. A central leader tree is characterized by one main, upright trunk, referred to as the leader. Branching generally begins on the leader 24 to 36 inches above the soil surface to allow movement under the tree.

Whether you obtain a small, unbranched whip or a larger, branched tree, it is necessary to prune the tree at planting. Cut the unbranched whip back to 24 to 30 inches from the ground. This will cause the buds just below the cut to grow and form scaffold branches. If branched one or two-year-old trees are planted, select four or five lateral branches with wide-angled crotches and that are spaced equally around the tree and 2 to 5 inches apart vertically. The selected laterals should be no lower than 18 inches above the ground, and they should be pruned back slightly by cutting off 1/4 of each limb’s length.

Figs

Begin training to bush form at the time of planting by cutting off one-third of the young plant to force shoots to grow from the base of the plant. Allow these shoots to grow throughout the first season.

Pomegranates

Cut trees back to 2 to 2.5 feet at planting and allow 5 to 6 vigorous suckers, evenly distributed around the stem to develop. Since the fruits are borne only at the tips of new growth, judiciously shorten the branches to encourage the maximum number of new shoots on all sides, prevent straggly development, and achieve a strong well-framed plant.

Blackberries and Raspberries

Blackberries and raspberries are biennial fruiting plants that may be trellised. They produce little or no fruit the first year. Little pruning is needed for blackberries and raspberries the first year.

Blueberries

The general rule is to remove 1/3 to 1/2 of the top of young blueberry plants when transplanting them to the field. Remove weak, twiggy growth near the base of the plant and side branches bearing flower buds. Remove flower buds the first and second year after planting to stimulate vigorous growth. Failure to remove flower buds from young plants can reduce canopy growth and delay plant establishment.

Muscadines

A Muscadine grape plant consists of a trunk and selected side shoots referred to as cordons. The cordons are spread out and attached to the trellis support wires. Pruning initiates growth of short lateral shoots called spurs that come directly off the cordons. The new fruit develops on these spurs. All shoot growth from last summer should be cut back so that spurs will all have from 2 to 4 buds each. Prune along each of the cordons or main side branches to eliminate excess competition. Cut off excess growth so that there is at least a 6 inch spacing between each of the spurs.

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Resource(s):

Simple Tree Training Techniques for Peaches

Center Publication Number: 258

Source(s): Susan Zaro, DeKalb County Master Gardener Volunteer, College of Agricultural and Environmental Sciences.

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Rabbits can do considerable damage to the landscape. For the most effective control, a variety of methods should be tried, including habitat modification, fencing, trapping, chemical repellents and the use of rabbit-resistant perennials.

Removing dense, heavy vegetative cover, brush piles, weed patches, junk dumps and stone piles adjacent to the landscape will help eliminate rabbit habitats. Fencing made from chicken wire, with mesh less than 1 “, can be placed around a vegetable garden or herbaceous plant border. The fence must be at least 2′ high with the bottom buried at least 3″ deep. You can also use cylinders of 1/4″ wire hardware cloth extending higher than a rabbit’s reach by placing them around the trunks of individual trees and shrubs. Bury the bottom of the cylinders 2″ to 3″ inches below ground level and place them 1 ” to 2″ inches from the trunk.

Live traps, most effective in winter, can be baited with corn cobs, oats, dried apples or rabbit droppings can also be used but then you must be ready to relocate the live animal.

Chemical repellents, which take advantage of a rabbit’s keen sense of smell and taste, can discourage rabbit browsing. Try one or more of the following:

• Dried blood meal
• Mole Med or Scoot Mole
• Predator Scent
• Repel
• Hinder
• Human hair
• Scott Rabbit
• Used kitty litter sprinkled around edges of garden
• Animal lard smeared on tree trunks
• Onions interspersed with other crops
• Ropel and Bonide rabbit-deer repellent

Note: These methods have not been tested by the University of Georgia, so their use is at your own discretion. Before applying, test the safety and effectiveness of products on a small area of your garden first.

Plastic snakes or owl decoys can scare away some rabbits, but often only on a temporary basis.

Another method for ridding the landscape of rabbits is setting half filled quart jars with water around the garden, although no one is sure why this has been found to be effective.

Finally, there are plants that are not as attractive a food source as some others:

• Yarrow
• Hosta
• Monkshood
• Red Hot Poker
• Wormwood
• Geranium
• Aster
• Iris
• Astilbe
• Bishop’s Hat
• Bellflower
• Narcissus
• Wild Indigo
• Yucca
• Snakeroot
• Oriental Poppy
• Autumn Crocus
• Lamb’s Ear
• Foxglove
• Sedum
• Daylily
• Globe Flower
• Leopards Bane
• Meadow Sage
• Meadowsweet
• Bergenia

If the presence of these adorable yet annoying creatures has you stewing, try a combination of the approaches mentioned above to gain the upper hand.

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Center Publication Number: 37

Source(s): Stephen D Pettis

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Cold injury, the damage caused to plants by freezing temperatures, may occur on the fruit, stems, leaves, trunk and roots. Water inside plant parts can freeze and expand, tearing cell walls and causing them to leak. This damage may go unnoticed until the plant fails to come out of dormancy in the spring.

There are three types of cold injury. The first is called a ‘burn’. Often cold damaged plant parts will become mushy and turn brown or black. Over time the damaged leaves or stems will dry out and appear to have been burned with a torch. Sunken areas may appear on branches and trunks and the bark may peel.

The second type of cold damage, desiccation, can be caused by winter winds. Cold air does not hold moisture like warm air (summer humidity and dry winter air) and can dehydrate plants if it is sustained for long periods of time. Leaves may dry up at the edges and eventually turn completely brown.

The third type of winter damage is wood splitting or ‘frost cracks’. This damage occurs on stems and branches. On particularly cold nights, water in the cells just beneath the bark of trees and shrubs freezes. When the sun hits these areas the next day, the water thaws quickly killing the cells and splitting the wood. Eventually, longitudinal (lengthwise) cracks may appear. Often these are not evident until the following summer.

Preventing cold damage to plants begins by planting plants that are native to our area or acclimated to the temperatures we experience. The USDA has created climatic zones based on average coldest temperatures for the regions of the US. Plants are categorized according to the areas in which they are hardy. Gardeners can choose plants that will perform in their area. For a map of the USDA hardiness zones they may visit the USDA website http://www.usna.usda.gov/Hardzone/ushzmap.html.

There are other ways to protect tender plants during the winter:

• Plant site selection can be crucial to winter hardiness of some plants. Planting under a tree canopy or near the southwest side of a home to maximize evening winter sun can protect plants.
• Plant nutrition can play a minor role in freezing. Maintaining proper fertility levels can lower the temperatures a plant can tolerate by 5 degrees.
• Windbreaks can be constructed or planted to block frigid winter winds.
• Plants can be covered with fabric on cold nights. Be sure to remove the fabric every day.
• Finally, watering plants keeps them hydrated and prevents plants from drying due to cold air and frozen soil.

 

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Resource(s):

• Winter Protection of Ornamental Plants
• Care of Ornamental Plants in the Landscape

Center Publication Number: 161

Source(s): Jacob G Price

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St. Augustinegrass is becoming increasingly popular in Georgia landscapes. This turf is susceptible to several insect and disease problems that occur in Georgia. Treatments for each situation are often very different so correct diagnosis is important before choosing a treatment option.

Chinch Bugs and Take-All Disease: (Fig. 1). Take- All Disease kills large areas of turf. Stolons, grass blades, and roots die, leaving turf that is easily pulled up. Roots are dark brown, and dark lesions are sometimes seen on stolons. (Fig. 2). Take-All Disease is usually associated with a pH of 6.3 or above at the soil surface. Incidences of Take-All Disease are increasing in Georgia. Chinch Bugs and Take-All Disease are the two most serious problems in St. Augustinegrass. (Fig. 3). Mature Chinch Bugs are about 1/8” long. Nymphal stages are reddish in color. If suspected, the fast moving insects can be found in thatch or on blades of grass in sunny areas of the lawn. The first symptoms of Chinch Bugs are yellowing of individual blades of grass which quickly becomes large brown areas.

Other Insects and Diseases: Brown Patch damages grass in circular patterns that enlarge to 8′. At first the area appears sunken. Excess moisture, high nitrogen fertilizer, and temperatures between 70-85 degrees, usually precede the outbreak. Gray Leaf Spot appears as tiny gray to brown spots on blades of grass usually in shaded areas with high moisture. Over-all appearance is irregular thinning of turf. Fairy-Ring is a disease that first appears as a lush green circle or semi-circle that moves outward with potential to leave bare areas of turf behind. Fairy-ring fungi often occur where roots or buried debris are decaying. Mushroom circles often appear in the fall. Mole Crickets are insects which feed on and sever roots which gives turf a spongy feel. Large irregular areas may die. They can be detected by pouring 1 gallon of water mixed with 2 tbsp of dishwashing liquid over the borders of the infested area. Sod Webworms and Fall Armyworms can also be detected with soap and water. The worms leave chewed edges on grass blades and can eat the grass to the ground. White Grubs are larvae of several types of beetles. Detection requires digging a square foot section to a depth of 4 inches and counting grubs. Treatment depends on the number and species detected. For more information and control options contact your local county extension office.

March	April	May	June	July	August	September	October
**Chinch Bugs				x	x	x	x
**Take-All Disease	x	x	x			x	x	x
Brown Patch	x	x					x	x
Gray Leaf Spot				x	x	x
Fairy Ring	x	x	x	x	x	x	x	x
Mole Crickets	x	x	x			x	x	x
Sod/Fall Armyworms							x	x
White Grubs		x	x	x	x	x	x

**Very serious and must be dealt with as soon as detected.

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Resource(s):
Turfgrass Diseases
Turfgrass Diseases: Quick Reference Guide

Center Publication Number: 244

Source(s): Stephen D Pettis

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The Crape myrtle (Lagerstroemia indica) is one of the most commonly used flowering trees in landscaping today. It also has the dubious distinction among gardeners and horticulturists as the plant that gets butchered in the worst way by homeowners and property maintenance companies.

‘Crape murder’ is a term used to describe the horrific pruning that many unfortunate crapes must endure and it isn’t far off the mark. The plants do not seem to mind particularly, as they are actually stimulated by extreme pruning. But, to those of us who empathize with abused creatures, the sight of mutilated crape myrtles is hard to stomach.

Crape myrtles are trained by nurseries into two basic shapes: single-stemmed tree-form and multi-stemmed. To achieve these shapes, growers allow crapes to grow for a year in either containers or fields, and cut them down to the ground in the spring of the second year. Later that summer when the plant has coppiced or grown many stems from the original root system, the grower will choose the single best stem and train it into a single-stemmed tree-form tree or choose an odd number of the best stems (3 or 5 for example) for a multi-stemmed tree. These trees are then grown out to salable size and purchased by landscapers and homeowners.

Pruning crapes so that they retain the appropriate form is relatively simple. Prune the trees in the winter when dormant. For trees that are just the right height or shorter, simply prune off the old flower heads and seedpods. If the tree was perfect last year but the past summer’s growth made the plant too tall, remove just that growth. Always remove any suckers that have sprouted from the roots or lower trunk. The key is to not allow the trees to get so overgrown that extreme pruning is ever necessary.

Sometimes though, we may forget to do our yearly maintenance pruning or it may be we take over a property where the previous maintenance person did a lousy job and now a harsh pruning is necessary. In either case, the trees can be pruned in such a way as to minimize the aesthetic impact of the removal of sizable portions of the tree. Begin by identifying the main stems and remove any others that might have suckered from the roots. Next, prune out any branches that rub and any branches in the interior of the tree that have suckered. Then decide the height you wish the tree to become. Make cuts at the very top of each trunk to remove any growth above that height. The tree may look a little flat-topped, but you can make shaping cuts to make the canopy the shape you want. I prefer the very top to be a little flat and to taper the sides into a rounded shape. One might describe it as umbrella shaped(see picture).

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Resource(s):

• Basic Principles of Pruning Ornamental Plants
• Crape Myrtle Culture

Center Publication Number: 112

Source(s): W.A. Attwater, University of Guelph, Ontario.

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DARK-WINGED FUNGUS GNATS (Diptera: Sciaridae). Dark-winged fungus gnats or sciarid flies, primarily in the genus Bradysia, are pests of ornamental and other potted plants.

Adults are 3-4 mm long and gray-black. They are common on soil surfaces or under leaves in moist shady places, especially in areas such as greenhouses. Adults are weak fliers and often run over the surface of soil. They are often attracted to lights in the house at night. Adults live approximately one week and do not cause feeding injury to plants.

Female flies can produce between 75-200 smooth, oval, white eggs which are laid on the soil surface and in crevices. Larvae emerge in 4 to 6 days and are creamy-white with black heads. Complete development occurs within 2-3 weeks at 22 °C, which is a common house temperature. The pupal stage appears as a thin cocoon, and lasts 4-6 days at 22 °C. Several generations of flies commonly overlap.

Larvae of several species feed on decaying organic matter and fungi in soil. Media mixes with a high peat content can favour infestations, especially in the presence of decaying plant tissue. The larvae also feed on rotting plant roots and lower stem tissue. They seldom affect sound plant tissue. Some species occasionally become pests in mushroom production operations.

Controls

• Remove breeding sites such as infested soil and decaying plant material.
• Replace infested mixtures with sterilized soil.
• Seal bags of opened sterilized soil.
• Allow the soil to dry between watering of houseplants.
• Follow good sanitation practises.
• Use screening on windows, doors and vents.
• Beneficial (entomopathogenic) nematodes and predatory mites are available for the control of fungus gnats.
• Insecticides with a domestic registration are also available.
• Use the recommended rates and follow all safety precautions given on the manufacturer’s label.

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Center Publication Number: 168

Source(s): Jim Howell, Ph.D., Entomologist, The University of Georgia

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Many areas considered to be in the “country” just a few years ago are now more urban. Because of this transition in land use, raccoons and other animals once called wildlife may now be considered backyard pests.

Identification

Raccoons are stocky, 2 to 3 feet long and usually 10 to 30 pounds. They are grizzled gray, with a bushy tail marked by alternating gray and black rings. The black “mask” across the face is the trademark feature by which most of us know them.

 

Biology

Though raccoons prefer a wooded habitat that includes water – lakes, rivers, marshes – they are amazingly adaptable, and many have found a relatively easy life in the urban and suburban environments of our cities and towns. In more forested areas, raccoons commonly den in hollowed trees, ground burrows or under brush piles. But in the urban environment, they have moved into our chimneys, attics and wall spaces.

Raccoons are omnivores, eating both plant and animal foods. Plant foods include berries, corn, fruit, nuts and vegetables. They are opportunistic hunters and feed on insects, grubs, crayfish, frogs, fish, bird eggs, nestlings, squirrels, rats and other small animals they can catch. They are most active at night, but sometimes they forage for food during the day.

Raccoons usually breed in February and March and bear one annual litter of three to five kits in April and May, though late matings can result in births as late as August. The home range varies from one to 20 square miles, depending on food or mate availability. They do not hibernate but may “hole up” in severe weather.

Damage

Raccoons can be a serious nuisance problem when they decide to enter our homes, using chimneys, attics or wall spaces as a replacement den instead of a hollow tree. For their size they are powerful animals and can rip off boards and shingles in search of a retreat. Raccoons are amazingly dexterous, too. In urban areas, they routinely open garbage cans and dump the contents in search of food. They often dig up sod in search of insects and earthworms, thus damaging our lawns. They may feast on unpicked vegetables as well, thereby destroying our gardens. Raccoons can even injure pets sometimes, such as cats and small dogs. Lastly, raccoons are a major wildlife reservoir for rabies in the United States.

Control

First of all, do not feed wild animals. Depending on your location, this may even be a crime. This activity encourages the animals to stay in the area and often results in their invading our homes. Bring pet foods in at night and store in a garage or other secure place. Place garbage in metal cans with tops that can be secured until pickup. Sprinkle soap flakes on the lawn and water in to help deter raccoons from digging up the lawn. Sprinkle diluted Tobasco over the vegetables in your garden to help deter raccoons from damaging your plants.

Inside Nuisance

If a raccoon has entered through a pet door, close off all other doors to the house. The animal may leave the same way it came in. If you hear noises in your chimney – whines, snarls, whimpers, etc., especially in February and May, it may well be a nest of raccoons. Do not start a fire in the fireplace in hopes of driving them out. The female will leave and the young will be left. The young raccoons can not escape. For chimney, attic or wall space removal, contact a licensed professional. Racccoons are considered game animals in many states and trapping them is illegal, if out of season and without proper permits. After the animal has been safely removed, take immediate steps to seal any possible entry sites.

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Center Publication Number: 233

Source(s): Wayne A Gardner, College of Agricultural and Environmental Sciences, Professor – Entomology Department

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A rain garden was recently added to the theme gardens in the Demonstration Area of the Research and Education Garden on the UGA Griffin Campus. This new theme garden shows homeowners and professional landscapers how to design and manage a rain garden.

Rain gardens are designed to capture and absorb stormwater run-off from landscape surfaces. Most of these surfaces are hard and impervious to water, such as sidewalks, driveways, and building roofs.

These gardens may be large, complex bioretention-gardens that collect stormwater from mall roofs and parking lots. This garden is an example of a smaller, home landscape garden that is designed to handle stormwater run-off from the home landscape, roof, and driveway.

Why try to capture and absorb stormwater? Rain gardens help reduce water pollution. Studies have found that 70% of the particulates and other pollution in our streams, rivers and lakes are carried there by stormwater. Incredibly, about half of the pollutants in stormwater are from landscaping and gardening activities like cultivating, fertilizing, pruning, clipping, and applying pesticides.

By capturing stormwater runoff, rain gardens also allow this water to be absorbed into the ground and to return to the water table by natural percolation.

The Rain Garden in the Research and Education Garden also serves as a research area for Rose Mary Seymour of UGA’s Biological and Agricultural Engineering Department. Seymour is collecting data on amounts of water captured by this rain garden following rainfall.

Tony Johnson, horticulturist for the Research and Education Garden, designed and coordinated the installation of the garden. Johnson learned that plant selection is critical to the success of rain gardens. We ask a lot of plants in a rain garden. They must be able to survive flooding for 48 hours, and they must tolerate prolonged periods of dry weather, even drought.

Johnson has already identified several plants that meet these challenges while adding to the beauty of the home landscape. He suggests the following as excellent prospects for rain gardens in Georgia and the Southeast:

American smoke tree, Cotinus obovatus
Joe Pye weed, Eupatorium purpureum
Black-eyed Susan, Rudbeckia fulgida ‘Goldstrum’
Serviceberry, Amelanchier x grandiflora
Chokeberry, Aronia arbutifolia ‘Brilliantissima’
Daylily, Hemerocallis spp.
Louisiana iris, Iris spp.
Swamp hibiscus, Hibiscus coccineus
Clethera, Clethera alnifolia ‘Ruby Spice’ & Clethera alnifolia ‘Sixteen Candles’
Mexican petunia, Ruellia brittonia
Purple coneflower, Echinacea purpurea
Oak leaf hydrangea, Hydrangea quercifolia

If you are homeowner or professional landscaper interested in installing a rain garden, you should visit the Rain Garden at the Research and Education Garden. It combines natural shapes and features with beauty to create an environmentally friendly garden. For more information on rain gardens, click on the links below to view Rose Mary Seymour’s, “Why Create A Rain Garden in Our Landscape?” and “How to Build a Rain Garden”

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Resource(s):

• Rain Gardens in the Home Landscape
• Landscape Plants for Georgia