Plant Trees and Shrubs in Big-Enough Holes

Many trees and shrubs are transplanted most successfully in the cool months of October through April. However, even the most wonderfully healthy plant will struggle if it is set into an inadequate or improperly prepared hole in the ground.

In the publication "Soil Preparation and Planting Procedures for Ornamental Plants in the Landscape," UGA's Gary Wade says that a big enough hole will be "at least twice as wide as the root ball" and only about as deep as that same root ball.

The temptation is to add compost or other organic amendments to break up the red clay that is in many of our yards. Wade says, though, that all that organic matter "can act like a sponge in the planting hole, absorbing and holding too much moisture and causing the roots to stay too wet."

He says that, instead, it is best to pack the same soil removed from the hole back in around the root ball. Be sure to remove and wires or burlap before planting, eliminate air pockets by watering-in the plant, and apply mulch in a doughnut-like circle around the plant to protect it from weeds and lawn-mower damage.

North Georgia Gardening Symposium, Feb. 26, 2015

The 2015 North Georgia Gardening Symposium is set for Thursday, February 26, at the North Metro Campus of Chattahoochee Technical College.

For landscape professionals, the Symposium provides for 5-hours pesticide re-certification credit for category 24 licenses or 1-hour pesticide re-certification for private applicators. It also has been approved for 5-hours (CEUs) for ISA Arborist and Municipal Specialists.

For everyone who attends, the Symposium offers a great opportunity to enhance garden and landscape knowledge and skills!

This year's offerings will help gardeners and landscapers avoid common mistakes in using broad-leaf herbicides, learn to diagnose common tree disorders in the landscape, and use the best and most innovative sustainable practices in landscape maintenance, and more.

8-8:30 a.m.                    Registration/Check-in 
8:30-9:30 a.m.               Herbicide Effects on Landscape Trees and Shrubs, by Paul Pugliese, Bartow County Extension
9:30 a.m.-10:30 a.m.      Creating Tough Turf, by Becky Griffin, UGA Extension Urban Ag Associate
10:30-10:45 a.m.            Break
10:45-11:45 a.m.           Tree Scene Investigation, Mary Carol Sheffield, Paulding County Extension
11:45 a.m. to 1:15 p.m.   Break for lunch and vendor visits 
1:15-2:15 p.m.                New Diseases, New Products, What Else is New?, by Dr. Jean Williams-Woodward, UGA Extension Plant Pathologist
2:15-3:15 p.m.               Sustainable Landscape Practices, by Dr. Bodie Pennisi, Extension Landscape Specialist
3:15-3:30 p.m.                Break
3:45-4:15 p.m.                The Latest and Greatest Plant Introductions, by Rex Bishop, Chattahoochee Technical College
4:15-4:30 p.m.                Pesticide re-certification/evaluation

The course fee is $35; lunch and breaks are included in the fee.

To register online, scroll down the list of courses for Continuing Professional Education to choose the North Georgia Gardening Symposium class and register. Also, you may call 770-528-4550 for more information or to register for the Symposium.

"Warts" on Pecan Leaves Can Be Galls

Wart-like Pecan leaf galls.          PHOTO/Renae Lemon

Over the past couple of weeks, several county residents have emailed photos and/or brought in examples of infested pecan leaves, concerned that their trees may be diseased.

UGA's publication "Pecan Trees for the Home or Backyard Orchard", by UGA specialists Lenny Wells, Will Hudson, and Jason Brock, explains that disease can interfere with good production of nuts, so it is easy to see why our residents would be concerned. A reduced harvest of delicious pecans would be a great loss!

The good news is that, so far, all of the affected leaves have been infested by galls, rather than disease. In the popped-open gall just above the 5 and 3/4 mark on the ruler in the photo above, one of the culprits is just barely visible, looking somewhat like a little white worm.

The University of Kentucky's publication "Pecan Insects"  offers this information about the leaf gall that is typically caused by an insect called Phylloxera:

"This aphid-like pest produces galls on new pecan growth. Leaves, twigs and nuts may be affected. Phylloxera over winter as eggs in bark crevices. In the spring eggs hatch and the tiny nymphs feed on tender young growth, secreting a substance which stimulates plant tissues to develop into galls. When the nymph matures, eggs are deposited in the gall. Young nymphs develop within the gall. The gall splits in several weeks liberating them. Several generations are produced each year, as long as there is fresh young growth on the tree.

Control is initiated with the use of a dormant oil application. During the growing season, controls should target the "crawler" stage before the galls form. Once the gall is formed the damage is done. The crawler is active just before or at bud-break. Controls initiated after the start of gall formation are not effective."

In other words, it's too late to treat now. Many of the infested leaves will fall, and it could be that nut production will be reduced, but the galls do not always appear on the same tree every year. It may help to clean up fallen leaves as part a control program.

A UGA in Thomas County Ag blog post has this to add about Pecan Phylloxera: "Many beneficial insects like lady bugs, lacewings, and syrphid fly larvae feed on phylloxera and eggs after each generation of galls open."

How to Plant a Tree (or Shrub)

How a tree or shrub is planted plays a big role in the future health and growth of the plant.

The GA FACES article "How trees, shrubs are planted determines their success", by William Tyson, UGA Extension Coordinator for Effington County, explains the steps, and reasons behind the steps, for planting these woody plants correctly.

Tyson explains the process:

1.  Before even bringing a plant home, check its roots to assess the root system. The plant will be less successful if the roots are compromised in any way. He says, "If roots are circling inside the pot and/or crossing over one another (girdling), prune at the crossover so the roots will grow outward."

2. Dig the hole:"When digging the hole that will become the plant’s new home, make sure it is two to three times wider than the size of the root diameter." The hole should be wide and shallow, so that the top of root mass will sit slightly above the level of the surrounding soil.

3. Do not overwater: "Plants need both water and air around their roots, so the soil should not be too wet. Too much water will cause the plant to lose new roots. Since there is a relation between roots and the amount of top canopy growth, the plant ceases to grow."

4. Wait to apply fertilizer: "It is best not to fertilize until the plant begins to grow. When the top of the plant starts growing, this indicates the roots have grown."

For Tyson's complete article, select (by clicking on) the linked article title above.

For additional information and details of planting large trees or on slopes, go to the UGA publication "Tree Planting Details" that contains a table of links to drawings and specific guidelines for these situations. 

Winterizing Trees

Kim Coder, professor of Tree Biology and Health Care with UGA's Warnell School of Forestry and Natural Resources, has published a list of steps homeowners can take to help insure that their trees make it safely through the winter dormant season.

The list has been posted on the Landscape Alert blog of UGA's Cooperative Extension. This is Coder's “Top 10 List” of things you can do to winterize your trees:

1. Remove or correct structural faults and deadwood that are clearly visible. Try to make small pruning cuts that minimize the exposure of the central heartwood core on branches.
2. Properly prune branches that will touch the ground when loaded with rain and snow. Foliage and branches that are in contact with soil can invite undesirable pests and problems.
3. Remove damaged and declining twigs, branches, and bark. Do not leave pests food and shelter for the winter.
4. Remove any new sprouts that have grown at the tree base, or along stems and branches. Pruning should conserve as many living branches as possible with only a few selective cuts.
5. Spread a thin layer of composted organic mulch to blanket the soil. Cover an area at least as large as the branch spread. Mulch is nature’s of recycling valuable materials, but be careful of pests hitching a ride.
6. Properly wrap new trees that have not developed a corky bark and could be easily damaged. Mechanical injury from the environment, including chewing and rubbing by animals, must be prevented.
7. Aerate soils if they are compacted and poorly drained. It is critical not to damage tree roots in the soil. Saturated and dense soil can suffocate roots.
8. Fertilize with all the essential elements, if they are in short supply within the soil. Be sure to go lightly with nitrogen, especially under large, mature trees and around newly planted trees.
9. Watering may be needed where soils are cool but not frozen, and there has been little precipitation. Winter droughts need treatment with water the same as summer droughts, except it is much easier to over-water in winter.

Plant Your Home Orchard Now

UGA Extension Specialist Bob Westerfield has written a couple of recent articles on planting a home orchard, pointing out in both that choosing the right trees for your area is an essential step toward a successful and productive orchard. Insect and disease resistance are important elements of that success, but so is timing.

In "Plant Fruit Trees Now to Create a Home Orchard," Westerfield points out that the best time is now.

The article explains much of what a homeowner needs to know to get a productive orchard started, including site selection -- emphasizing drainage and sunshine -- ground preparation, and planting. Usefully, it also explains how to select a healthy tree for planting. Westerfield recommends the purchase of one-year-old trees:

"A common mistake made by many homeowners is to select oversized or ready-to-bear nursery trees. Experience has shown that younger trees bear almost as soon, are easier to keep alive and develop into more healthy vigorous trees than do oversized stock. Older trees cost more to grow and are sold at higher prices, but are usually worth less."

In "Select Best Fruit Trees for Your Region of Georgia," Westerfield identifies fruit tree varieties that perform well in the different regions of the state.

Recommended apple trees for Cobb County include "Ginger Gold, Gala, Mollie’s Delicious, Ozark Gold, Golden Delicious, Mutzu, Yates and Granny Smith."

For pears, choose "Orient, Carrick Waite, Kieffer, Magness, Moonglow, Starking Delicious or Dawn."

For plums, he recommends the Japanese varieties  "Methley, Morris, AU Rubrum, AU Producer, Spring Satin, Byrongold and Rubysweet."

Apples hang from a tree at the University of Georgia - Mountain Research and Education Center in Blairsville, Ga. Image credit: University of Georgia.

In addition to the information in the two articles linked above, homeowners interested in starting a small orchard out in the yard can refer to the information in UGA Cooperative Extension's multiple fruit/orchard publications: "Minor Fruits and Nuts in Georgia"; "Home Garden Pears"; "Home Garden Apples"; "Home Garden Figs"; "Plums for Georgia Home Gardens"; and "Diagnostic Guide to Common Home Orchard Diseases", among others.

For additional information, or for UGA publications on fruits not listed here, contact the Cobb County Extension office at 770-528-4070.

Putting the Pruning Shears to Work

As winter begins to wane, the urge to get busy in the yard, preparing for the spring, is almost overwhelming for many gardeners. If the lawn is planted in a "warm season" turf-type like Bermudagrass, it's too early to do much work on the lawn. It's also too early for planting much of the vegetable garden. However, the flowering trees and shrubs can be a good place to focus some of that gardening energy.

According to the UGA publication "Pruning Ornamental Plants in the Landscape" by  Extension Horticulturists Gary Wade and James Midcap,

"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."

The phrase "just prior to spring growth" means that the window of opportunity is going to be closing soon, for many of the summer-flowering shrubs.Wade and Midcap include not only instructions for how to prune woody ornamental plants, but also a useful list of shrubs and small trees to prune in late winter:

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

For roses, an illustration within the publication (and pasted here) offers gardeners some additional guidance in how to shape the different types of roses. More information about rose culture in Georgia can be found in the UGA publication "Roses in Georgia, Selecting and Growing Techniques."

Additional information about pruning crape myrtle, an especially well-loved landscape shrub, can be found in the UGA publication "Crape Myrtle Culture."

Hopefully, the publications linked above will provide some direction for the gardener's pent-up energies as he or she contemplates the coming of another beautiful spring.

Best Time to Plant Shade Trees is Now

According to UGA Cooperative Extension's Frank Watson, fall is the perfect time to plant trees to provide summer shade in the coming years. In a recent article, he wrote, "Fall planting allows tree root systems to become established and supply the moisture needed for next spring's growth. This way your trees will get off to a great start."

Watson recommends that homeowners consider several factors in selecting the perfect tree for the proposed planting site. Among these factors are the amount of space available for the tree, whether there are any overhead wires, where the shade needs to be cast in order to provide the most help for the homeowner, the importance of flowering and/or fall color, the strength of the wood, and the pest and disease resistance desired.

The UGA publication "Shade Trees for Georgia" includes a very helpful table that addresses many of the above characterstics. The publication also explains how to plant the tree, starting with the size of the hole that needs to be dug:

"A large planting hole, two to three times the size of the root ball and with well-tilled backfill soil, will produce satisfactory results. Organic soil amendments placed in the planting hole will NOT produce a superior tree (although their use in annual and perennial beds is recommended). Research indicates that the best use of organic materials when planting trees is as mulch. Over time, mulch will decompose into the soil, adding much needed organic matter.

For best results, add organic matter or compost to the entire landscape prior to planting...

Plant at the proper depth, avoid excessive packing of the fill-soil, water the tree in after planting and mulch with 2 inches of an organic material such as pine bark or 4 inches of pine straw. Trees should receive 2 tablespoons of a 12 percent to 16 percent nitrogen fertilizer (12-4-8 or 16-4-8) per 10 square feet of root area. Do not apply large amounts of fertilizer until the trees are established, usually after the first year. After broadcasting the fertilizer evenly over the planting area under the crown of the tree, water it in.

The single best cultural requirement you can provide to a young tree is water during establishment. Establishment in the landscape is helped tremendously with as little at 40 gallons added over the first season after planting."

Taking the time to choose the right tree for the spot and to prepare the planting hole correctly will go a long way toward promoting the good health and growth of your new tree!

Drought Continues, and Trees Still Need Water

This week's update for Georgia on the U.S. Drought Monitor website shows that Cobb County is still experiencing extreme drought conditions. Sure, we've had some rain, but we are far enough behind that the deeper soils are dry. Here is the Oct. 23 update:

Overall, the state is in better shape with regard to rain this year than it was last year, with much of the agricultural southern end completely "caught up," but here in Cobb County we will need to keep track of the rain and the soil moisture levels a while longer.

Valuable landscape trees are of particular concern. These need to be kept watered, in spite of the cooler temperatures and falling leaves, according to the UGA publication "Watering Trees During Winter Drought." The publication was written for the 2007 drought, but the recommendations are just as applicable in 2012:

"Dormant season watering during a winter drought is important, especially for evergreen trees and juvenile hardwood trees that have not lost their leaves. Because of lower temperatures and relative humidity, much less water is required in the dormant season, but water is still needed. Drought conditions can lead to tree decline, pest 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."

The publication explains how to determine the amount of water needed and how to apply it safely, with a note to avoid watering when the soil surface temperature is below 40 degrees F.

Drought Still a Danger for Trees

In spite of recent rains, Cobb County is still experiencing Extreme Drought conditions, as shown on the U.S. Drought Monitor website of the National Drought Mitigation Center.  Conditions have been dry enough for long enough that many trees that have not been watered adequately are showing signs of drought stress.

Different plants will show the stress differently, but in general, leaves may curl, wilt, turn yellow or brown, or drop off completely. Maple trees, for example, tend to lose leaves from the ends of their furthest twigs, almost giving them the look of having just had a burr haircut. Since symptoms of drought stress can resemble damage caused by diseases and insects, calling the Extension Office to check for other possible causes of problems is a good idea.

Instructions for providing adequate water to trees are included in the section on irrigation in the UGA Cooperative Extension publication "Shade and Street Tree Care”:

"Apply water to mature trees after two to four weeks without normal rainfall. Water deeply and infrequently to recharge the root zone. Check the depth of water penetration by pushing a thin steel rod into the soil. The probe will push easily through wet soil but with difficulty through dry soil. Probe the soil two to three days after watering to determine depth of penetration, and make sure the water is reaching a depth of 12 to 18 inches. Allow the tree to absorb the water before the next irrigation."