Tidewater Gardening - October 2013

Fall is for Planning and Planting


K. Marc Teffeau

With the cooler temperatures and shorter days, October is a gardening transition month, as is April in the spring, where we engage in both planning and planting. As I have mentioned a number of times through the years writing Tidewater Gardening, September through November is an excellent time to plant woody trees and shrubs. With few exceptions like bareroot pines, dogwoods, birch, magnolia, poplar and redbud, trees and shrubs will do well when planted in the fall.
The local garden centers and nurseries usually have a supply of both container-grown and balled-and-burlapped plant material available. As long as the soil temperature stays consistently above 40°, the plant roots will grow.
If you want to transplant an existing deciduous shrub or tree in the landscape, I would wait until after the first or second hard frost to make sure that the plant has hardened off. You can plant container and balled-and-burlapped evergreen shrubs now, but I would wait until the late winter or early spring to transplant evergreens from one place to another in the landscape.
We usually recommend mulching newly planted trees and shrubs to reduce weed problems and to conserve moisture. In the fall, however, it is usually a good idea to wait to mulch until after the soil temperatures have reached 32°. Mulch applied too early can do more harm than good.
Mulch is used to keep soil temperatures constant and to prevent frost heaving, not to keep it warm. In October, the trees and shrubs start to harden for the upcoming cold weather. To encourage this process, remove mulch from around the stems of shrubs and trees. This will also discourage mouse and vole damage to the stems during winter.
Remember to provide adequate water to any newly planted tree or shrub if the fall happens to be dry. Do not over-water plants in heavy clay soil. A good deep soaking is usually all that is needed. Check out the online publication HG 24 - Planting Tips for Trees on the University of Maryland Home and Garden Information Center website ~ http://extension.umd.edu/hgic for specific guidelines for proper tree planting.
In August I had the opportunity to attend the Southern Nursery Association 12th Southern Plant Conference in Atlanta. The speaker list included a number of industry “heavy hitters” like Dr. Mike Derr, Dr. Alan Armitage, Dr. Richard Olsen from the U.S. National Arboretum, and Dr. Tom Raney from North Carolina State University, to name a few. All of the speakers presented on what they thought were the best established and new and upcoming ornamental plants. Maryland is considered in this “Southern” zone, so a number of plants that were recommended do well in Maryland, especially on the Eastern Shore.
Out of the literally hundreds of perennials, shrubs and trees presented and discussed, a couple caught my attention. Red Vein Enkianthus is an under-used shrub that would pair well with azaleas and rhododendrons as it is also a member of the Ericaceae family. It requires an acidic soil and does well in full sun or partial shade.
In the springtime. this shrub is covered with a profusion of bell-shaped flowers and can be white with pink stripes or dark red. During the fall, the 1-inch to 3-inch elliptical leaves change to hues of red, orange and yellow.
A native of Japan, this species is slow to grow and may take many years to reach maturity. The red vein enkianthus naturally forms into a pleasant shape and the only pruning you should need to do is take care of any branches that are dead, diseased or damaged. Prune just after the plant has finished flowering so you do not affect the next year’s blossom crop.
The cultivar that was recommended by Ted Stephens from Nurseries Caroliniana was Enkianthus quinqueflorus ‘Pink Chandelier’ that produces waxy pink flowers in the spring.
I have always been fascinated by the fall and winter flowering trees in the family Hamamelidaceae or Witch-hazel family. The witch-hazels are deciduous shrubs or small trees growing from 9 to 26 feet tall. They are popular ornamental plants, grown for their clusters of rich yellow to orange-red flowers that begin to expand in the autumn and continue throughout the winter.
A lesser-know member of the Hamamelidaceae family that was featured at the Southern Plant Conference is Rhodoleia. Specifically recommended was Rhodoleia henryi because it is a more cold-hardy species than its better-known relative, Rhodoleia championii.
This unusual broadleaf evergreen in the family Hamamilidaceae is from China and has exquisite geometrically shaped rose-red flowers up to 0.8 to 1.6 inches in diameter and is a more cold hardy species than R. championii.
The specific cultivar ‘Takeshita’ was recommended, and it offers deep pink flowers rather than the red found in the species. This species grows as a large shrub to small tree.
While you are in the process of cleaning up the flower beds this month, don’t forget that this would be a good time to divide and transplant perennials that have spread or outgrown their location in the flower bed. New perennials can still be planted in the fall, and established perennials can be divided.
Autumn is the perfect time to fill the empty spaces in an established garden with new plants. If you are going to do this, I would recommend that you not wait until the end of October, but do the planting and transplanting early in the month to give the plants enough time to get established.
Dig tender, garden flower bulbs for winter storage. Gladiolus corms should be dug when leaves begin turning yellow. Caladiums, geraniums and tuberous begonias should be lifted before killing frost. Dig canna and dahlia roots after a heavy frost. Allow to air dry, then pack in dry peat moss or vermiculite, and store in a cool location.
If you did not do it last month, now is also a good time to add chrysanthemums, pansies, and ornamental kale and cabbage to the flower bed planting to provide a last-minute pop of color. Pansies have many applications in the winter landscape. They add drifts of single-colors to an otherwise dull winter landscape or as a mass planting with several colors mixed together. Use pansies in a flowerbed with colors appropriate for holidays such as red and white for Christmas.
Pansies in particular perform best in cooler weather and are, therefore, usually planted in spring or fall. They like rich, well-drained soil high in organic matter, and full sun or partial shade. Pansies will flower even more profusely and longer if spent flower heads are removed.
Pansies grow best when night temperatures are below 65 °, which makes them ideal for fall gardens. Pansies can survive temperatures as low as 2° in the winter.
A big plus with the pansy is the variety of colors. Pansies can be purchased in almost every color of the rainbow, even those with black flowers! There are solid colored pansies and pansies with faces.
Pansies also come in a variety of sizes. The large category has blooms that range in size from 3½ inches to 4½ inches. Medium size blooms run 2½ inches to 3½ inches. The small, or multiflora, bloom sizes run 1½ inches to 2½ inches. Generally, pansies with smaller flowers tolerate heat and adverse growing conditions better than the large flowered types.
In most cases, pansies perform much better in the landscape if you do a good job of preparing the soil. Choose a location that is well drained. Pansies will not grow well in soil that stays constantly wet. Work 4 to 6 inches of organic matter, such as garden compost, peat moss, soil conditioner or well-rotted leaves, into the soil with a shovel or tiller. Pansies grow best in a soil with a low pH, so little if any limestone is usually needed. They don’t need a high amount of fertilizer, so fertilize sparingly.
Plant pansies in the bed at about the same level they were growing in the packs, or just slightly higher. Don’t plant them too deep, with soil covering the stem. After planting, water the bed thoroughly to a depth of at least 6 to 8 inches. Remember to check the bed for watering in the first 3 weeks or until they establish a root system and begin growing.
In the vegetable garden finish your fall clean up and dispose of any disease and insect infested plant debris. Harvest root crops and store in a cold (32°), humid location. Storing produce in perforated plastic bags is a convenient, easy way to increase humidity.
Harvest Brussels sprouts as they develop in the axils of the leaves, from the bottom of the stem. Brussels sprouts will continue to develop up the stem.
Harvest pumpkins and winter squash before frost, but when the rind is hard and fully colored. Store in a cool location until ready to use. Harvest gourds when stems begin to brown and dry. Cure at 70° to 80° for two to four weeks.
Harvest mature, green tomatoes before frost, and ripen indoors in the dark. Warmer temperatures lead to faster ripening. Asparagus top growth should not be removed until foliage yellows. Let foliage stand over winter to collect snows for insulation and moisture.
Now is a good time to have the garden soil tested to determine if you will need to add lime and any additional fertilizer next spring. In fact, fall is an excellent time to add lime to the garden soil, if needed, because the alternate freezing and thawing of the soil over the winter will help work the lime down into the soil.
Now is also a good time to plow and incorporate organic matter to avoid the rush of garden activities and waterlogged soil in spring. Fall-prepared soils also tend to warm faster and allow earlier planting in spring.
Herbs brought indoors for fall and winter should be located where they will receive strong direct sunlight. Supplemental fluorescent light (cool white bulbs or grow lights) will probably be necessary as well. Keep lights on for 14 to 16 hours each day. Keep herb plants away from drafts and heat sources and mist them daily.
Happy gardening!

Marc Teffeau retired as the Director of Research and Regulatory Affairs at the American Nursery and Landscape Association in Washington, D.C. and he now lives in Georgia with his wife, Linda.