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.

Upcoming Events and Classes

Suburban Home Vegetable Garden

Tuesday, February 9, 7:00 – 8:00 p.m. Master Gardener Vicki Baroni will tell how families can grow vegetables and some fruits with ease. Part of the Gardeners Night Out series of Cobb Master Gardeners.  At West Cobb Regional Library, 1750 Dennis Kemp Lane NW, Kennesaw, 30152.

Thyme to Read Book Club

Friday, February 12, 10:15 – 11:30 a.m. This month’s book is The Scent of Scandal: Greed, Betrayal, and the World’s Most Beautiful Orchid, by Craig Pittman. In the Training Room of the Cobb County Water Lab, 662 South Cobb Drive (at the intersection with Atlanta Rd.).

Compost and Soil Amendments

Friday, February 12, noon – 1:00 p.m. Learn how poor soil can be turned into plant-friendly soil with Master Gardener Eddie Rhoades. Part of the Lunch and Learn series of Cobb Master Gardeners.  In the Training Room of the Cobb County Water Lab, 662 South Cobb Drive (at the intersection with Atlanta Rd.).

Seed Starting Workshop

Tuesday, February 23, 6:30 – 7:30 p.m. Learn how to start vegetable garden transplants from seeds, with Master Gardener and Cobb Extension staff member Amy Whitney.  In the second floor classroom at UGA Extension/Cobb County, 678 South Cobb Drive, Marietta, GA, 30060.

North Georgia Gardening Symposium

Thursday, February 25, 8:00 a.m. to 3:30 p.m. For homeowners, Master Gardeners, and landscape professionals. Re-certification credits available: 3 hours for category 24, 1 hour for Private pesticide applicators, 5 CEUs for ISA Arborist (A) and Municipal (M). Chattahoochee Technical College, North Metro Campus, Building D, Room 400, 5198 Ross Rd., Acworth, GA, 30102. Program cost $35 includes lunch and breaks. Register by February 22 at 770-528-4550, or online.

Orchids 101

Thursday, March 3, 1:30 – 3:00 p.m. Presented by Master Gardener Sondra Nierenberg, this is the first of three presentations in an Orchid Care series. In the second floor classroom at UGA Extension/Cobb County, 678 South Cobb Drive, Marietta, GA, 30060. Second class is "Orchid Diseases" on March 10, same time; third class is "Re-potting Orchids", March 24, same time. Registration and $15 class fee (for 1 or all in series) are due to the Cobb Extension office by Feb. 20.

A Few of My Favorite Things: Native and Non-Native Plants

Tuesday, March 8, 7:00 – 8:00 p.m. Learn about favorite native and non-native plants for home landscapes with Master Gardener Carmen Cudd. Part of the Gardeners Night Out series of Cobb Master Gardeners.  At Mountain View Regional Library, 3320 Sandy Plains Road, Marietta, GA, 30066.

Orchid Diseases

Thursday, March 10, 1:30 – 3:00 p.m. Second of three presentations in the Orchid Care series. In the second floor classroom at UGA Extension/Cobb County, 678 South Cobb Drive, Marietta, GA, 30060.
Registration and $15 class fee (for 1 or all in series) are due to the Cobb Extension office by Feb. 20.

Thyme to Read Book Club

Friday, March 11, 10:15 – 11:45 a.m. This month’s book is Grandma Gatewood’s Walk, by Ben Montgomery.  In  the Training Room of the Cobb County Water Lab, 662 South Cobb Drive, Marietta, GA, 30060 (at the intersection with Atlanta Rd.).

Small is the New Big: Small Gardens with Impact

Friday, March 11, noon – 1:00 p.m. Learn how to have a home garden that lives large regardless of size with Master Gardener Pam Bohlander. Part of the Lunch and Learn series of Cobb Master Gardeners.  In  the Training Room of the Cobb County Water Lab, 662 South Cobb Drive, Marietta, GA, 30060 (at the intersection with Atlanta Rd.).

Vegetable Garden Seminar

Saturday, March 12, 9:30 – 11:30 a.m. Presented by Cobb and Douglas County Extension offices and Douglas County Master Gardeners, this seminar covers plant selection and seed starting for the vegetable garden. Lithia Springs United Methodist Church, in the Fellowship Hall, 3711 Temple St, Lithia Springs, GA 30122. Advance registration and $6 fee are requested. For information, call 770-948-5429.

Bluebird Trail Walk

Saturday, March 19, 10:00 a.m. – noon. Presented by Master Gardener Jim Bearden in association with the Atlanta Science Festival. On the 2.3-mile Bluebird Trail at Green Meadow Preserve Park, at 3780 Dallas Hwy., Powder Springs, GA, 30127.

Cherokee Medicinal Plants

Saturday, March 19, 1:30 – 2:30 p.m. Presented by Master Gardener Tony Harris in association with the Atlanta Science Festival. At the Cherokee Garden at Green Meadow Preserve Park, at 3780 Dallas Hwy., Powder Springs, GA, 30127.

Re-potting Orchids

Thursday, March 24, 1:30 – 3:00 p.m. Third of three presentations in the Orchid Care series. In the second floor classroom at UGA Extension/Cobb County, 678 South Cobb Drive, Marietta, GA, 30060.
Registration and $15 class fee (for 1 or all in series) are due to the Cobb Extension office by Feb. 20. 

Grow Your Own Food: From the Ground Up

Tuesday, March 29, 6:30 – 8:00 p.m. Taught by UGA Horticulture Specialist Bob Westerfield. This is the first class of a four-part series. Class Fee for series is $35. Preregistration and payment by March 15 are required. All classes to be held in the second floor classroom at UGA Extension/Cobb County, 678 South Cobb Drive, Marietta, GA, 30060. Call 770-528-4070 for information about the series.

How to protect ornamental plants in winter

In anticipation of the colder weather to come, homeowners are beginning to think about how to protect their favorite shrubs and perennials from the lowest temperatures. The UGA publication "Winter protection of ornamental plants", by Extension horticulturist Robert Westerfield and horticulture professor Orville Lindstrom, explains that, with proper care during the rest of the year, many plants will take care of themselves.

They describe the process like this:  "During the late summer and early fall, the plants must prepare themselves for winter through a process called cold acclimation. This process is initiated by the cooler temperatures and shorter daylengths that naturally occur at this time of the year."

Proper care includes providing nutrients (through fertilizers) during active growth in warmer seasons, withholding excess nitrogen fertilizer in fall. Westerfield and Lindstrom explain:

"Fertilizing plants in the fall (after August or September) with a fertilizer high in nitrogen can cause a flush of new growth that is more susceptible to cold temperatures."

Lawn and Garden Tips for March

Cobb County Extension staff member Louise Weyer assembles a list each month of tips for keeping your lawn and landscape in good order. As winter nears its end, following Louise's checklist of tasks can help your yard shift successfully to warmer-weather mode and improve the odds of its shining through the spring.

Louise's Tips for Trees and Shrubs for March includes this information:

• Prune roses, camellias, crape myrtles, late-flowering clematis, and butterfly bush.
• Delay pruning of early-blooming shrubs, such as forsythia, quince, and weigela, until after they bloom.
• Prune out dead stems on all shrubs and trees.
• Clean blades of pruning tools with alcohol or a bleach solution (1 part bleach to 9 parts water) to reduce spread of disease.
• Spray multipurpose fungicide on roses when leaves appear, to control black-spot.
• If major renovation of broadleaf evergreens is needed, prune those now.

When Can I Prune My Knockout Roses?

PHOTO/UGA Horticulture Specialist Bob Westerfield

Easy-care Knockout roses provide summer-long color in many of our landscapes, but to bloom their very best a little pruning helps, and the best time for pruning in Cobb County is nearly upon us.

Clemson University's "Ask a Master Gardener" publication "Pruning Knockout Roses: When and How," says "Rose pruning should be done just as buds break dormancy...probably around late February or early March. When the buds have swelled but no new growth has yet appeared, it is the ideal time to prune bush or shrub type roses."

North Carolina State University (NCSU) Extension's "Pruning Knock Out Roses" agrees with that timing, saying "Rose pruning should be done just as buds break dormancy, usually around mid-to-late February or early March in Zone 7. A good rule of thumb to help you remember is 'prune your roses when the forsythia is in bloom.'"

NCSU's instructions include the qualifiers, to wait until the second and possibly even the third year of growth before pruning, and that some shaping and thinning can be done in the summer, if needed. This summer thinning is especially useful to eliminate any points of contact where branches touch or rub against each other, to reduce spots where disease might enter the plant.

Clemson's publication explains the best method of figuring out where on the cane to make a pruning cut:

"Prune the bush to make it more open in the center. This will increase air circulation and help prevent diseases. Since rose bushes send out new growth from the bud just below a pruning cut, try to make pruning cuts above a leaf bud facing out from the center of the plant. Make a cut 1/4 inch above the bud and angled at the same angle as the bud."

UGA's Georgia FACES article "Prune Roses Now for More Blooms Later," by UGA Extension's Frank Watson, adds an emphasis on checking the pith, or center, of the stem after it's been cut. If the center is creamy white or greenish, then the stem is healthy, but if it is brown or black, Watson recommends "continu[ing] to cut down the cane until green or white pith is revealed. In some cases this may mean a drastic reduction of the cane. Occasionally, the pith will become darker with each successive cut, and the cane will have to be removed at the bud union using a small pruning saw."

For further information, read the complete articles at the links as they appear above.

For those who have not planted Knockout roses, but who are planning to, the UGA publication "Roses in Georgia, Selecting and Growing Techniques," by Horticulturists Bob Westerfield and Malgorzata Florkowski and Technical Assistant Adrianne Todd, provides a clear and easy-to-follow description of how to plant and care for your new roses, to promote abundant bloom.

Azalea Leaves Turning Yellow, Dropping?

Evergreen Azalea in early December.  PHOTO/Amy W.

When leaves of a favorite, beautiful azalea turn yellow and begin to drop, a homeowner might become somewhat alarmed. We tend to think of azaleas as being evergreen, and in our minds, "evergreen" is nearly the same as "never-yellow."

However, the UGA publication Selecting and Growing Azaleas, by Extension specialists Wade, Braman, and Woodward, in cooperation with members of the Azalea Society of America, points out that not all azaleas are evergreen, and for those varieties, total leaf-drop is completely normal.

It turns out that some leaf yellowing and loss is completely normal for evergreen azaleas, too.

In the online article Are Your Evergreen Azalea Leaves Turning Yellow or Reddish-Purple This Fall?, Joey Williamson, of Clemson's Home and Garden Information Center, explains:

"Remember that no leaf lasts forever. The older leaves, further down the stems, will fall off during the late fall and early winter season..." He adds, "White and pale-pink colored azaleas will typically have bright yellow-colored foliage just before leaf drop."

For information about selecting, planting, and care of azaleas in the landscape, along with descriptions of other potential causes of leaf yellowing and lack of vigor in azaleas, read the UGA publication linked above.

For azaleas about which the cause of a problem is unclear, the local Extension office can be contacted to provide assistance in tracking down the cause.

When Evergreen Shrubs Turn Brown from a Hard Freeze

When the leaves of azaleas, camellias, gardenias, and other evergreen shrubs turn brown after a hard freeze in winter, the instinctive first step that a  homeowner wants to take is to prune away the ugly, dead-looking parts of the plants. Instead, the first action to take is to keep away from the pruning shears!

UGA Extension's Keith Mickler, in the GA FACES article "Don't prune ice-covered ornamental plants until spring," says "The best advice for now is the 'wait and see approach.'"

He explains: "Severe pruning should be delayed until new growth appears in the spring. Waiting ensures live wood is not removed." Mickler adds, "Pruning away dead wood can expose buds, which may still be alive, to harsh elements. Another hard freeze just might wipe out any survivors."

For those who consider the browned leaved too unsightly to allow them to remain in the landscape, Mickler says that the dead leaves may be removed.

For additional information about caring for ornamental plants in winter, see the complete article, linked above, and UGA's publication "Winter protection of ornamental plants."

Annual 4-H Plant Sale

Flyers for the 2014 4-H plant sale are here! This annual fundraiser includes plants for nearly every landscape, offering hardy and productive varieties of berries, muscadines, and figs, and flowering shrubs and perennials for sun and for shade, including a shrub for semi-shade, the fragrant Daphne relative Edgeworthia chrysantha that flowers on bare stems in winter.

New for this year are two ferns, Autumn fern and Tassel fern, the shrub Flowering Quince, variety Cameo, and an ornamental grass, Miscanthus 'Purperescens', that has reddish tinged green blades in summer turning orange-red in fall and burgundy in winter.

As in the past, plants are ordered through the Cobb County Cooperative Extension office, and the prepaid orders are picked up at Jim Miller Park on one day only; this year that day is Saturday, March 15, from 9 a.m. to 3 p.m.  The deadline for the prepaid order  is Friday, March 7.

For those whose gardens are full but who would like to support 4-H, donations are also very much appreciated.

For more information about the plants, including pricing and specific varieties available, pick up a copy of the 4-H Plant Sale flyer-and-order-form at the Cobb County Cooperative Extension office or download one from our website. To download, go to the homepage, then click on the button below the words


.
that are below the program area links.

Anyone interested in learning more about growing the offered fruits at home is invited to attend a presentation by Agriculture Agent Neil Tarver on Wednesday, March 5, from 6:30 - 8 p.m. at the Cobb Water System Training lab. He will present information about the ornamental plants on Monday, March 3, from 6:30 - 8 p.m. at the same location.

To register for either seminar, call 770-528-4070, or check the appropriate box on the 4-H Plant Sale flyer-and-order-form.

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. 

Rough Year for Boxwoods in Cobb County

Recently, we have seen a lot of troubled Boxwood shrubs, brought in by County residents, here at the Cobb County Cooperative Extension office. Several samples have been sent to UGA's pathology lab, and although a couple of reports have listed disease pathogens such as Volutella as causing some of the trouble, others have cited root problems as the likeliest cause of decline for the sample.

In particular, wet conditions (remember all that rain we had in spring and early summer?) leading to root decay was noted in more than one report.

Virginia Cooperative Extension's publication Selecting Landscape Plants: Boxwoods explains how to select, plant, and care for Boxwood shrubs, and it includes this information about tolerance of Boxwoods to moist soil conditions:

"Boxwoods can grow in a variety of soil textures (relative amounts of sand, silt, and clay), but too much sand (a low water-holding content) or too much clay (too high a water-holding content and too low an air-holding content) should be avoided. A soil that is well-drained is essential; thus, low areas of the landscape that tend to stay moist or wet do not support boxwood growth."

In other words, Boxwoods are not at all tolerant of soil that doesn't drain well and that stays wet for extended time periods. If more Boxwoods out there are struggling, a closer look at the soil conditions might show that poor drainage is part of the problem.

In addition to being a little bit finicky about soil conditions, Boxwood shrubs here in North Georgia have a full measure of pest and disease problems, but Virginia Cooperative Extension's Boxwoods information page notes that deer typically don't eat boxwood, making it an attractive choice for neighborhoods that are troubled by deer.

For those whose Boxwoods are not doing well right now, Clemson University's publication Boxwood Diseases and Insect Pests contains helpful descriptions and photos of commonly seen Boxwood problems.

UGA's Landscape Alert October 18 blog post Boxwood Blight Update by pathologist Jean Williams Woodward tells about a fairly alarming new Boxwood Blight that has not yet made it to Georgia. The update (click on the linked title to see the original blog post) contains photos and a full description, along with tips that can help keep this disease out of our landscapes. This is the "bottom line" in preventing the spread of this fast-moving disease:

"You won’t get this disease if you don’t bring in any boxwoods. The spores are not wind-borne; they are water-splashed and carried on plants, people, tools, and animals. If you do bring in boxwood plants, make sure they come from a nursery certified to be free of Boxwood Blight."

Specifically, to reduce the spread of this disease, Woodward suggests disinfecting tools that are used on or around Boxwoods and considering propagating your own plants from Boxwoods that are known to be free of this new Blight.

For all Boxwood problems, prevention through appropriate variety selection and careful planting-site preparation and maintenance practices are key to our being able to enjoy healthy, beautiful plants in our landscapes for years to come.

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.