March 2013 - Tidewater Gardening

Spring Has Arrived!

by

K. Marc Teffeau

March heralds the arrival of spring and the anticipation of a new gardening season. One of the topics that I like to cover in Tidewater Gardening is the “Perennial of Year” from the Perennial Plant Society, and this year is no exception. A rather unique perennial, and one that is native to the Eastern Shore, has been selected for 2013.
Fragrant Solomon’s Seal or Polygonatum odoratum ‘Variegatum’ has arching stems that carry pairs of small, bell-shaped, white flowers in mid to late spring. The variegated ovate leaves are soft green with white tips and margins. Fall leaf color is an attractive yellow. Bluish-black berries are sometimes present in the autumn
We can find the native Solomon’s Seal, Polygonatum biflorum ~ Smooth Solomon’s Seal, in shaded moist areas in Eastern Shore woodlands. This plant prefers a rich organic soil with a pH in the acidic to neutral zone. Being a native species, the best growing environment is some shade. Damp shade is preferred, although once established, they are quite drought tolerant.
Requiring shade makes Solomon’s Seal an excellent plant for shaded garden areas and can be used to offer contrasting highlights in shaded areas of borders, woodland gardens, or naturalized areas. A good use is as a great companion plant to other shade lovers including hostas, ferns, and astilbes.
When in bloom, its flowers produce a sweet fragrance that will enhance your walk along a pathway on a spring morning. An added use is that the variegated foliage is attractive in flower arrangements.
Solomon’s Seal is also deer resistant, easy to grow and will reach a height of 18 to 24 inches. It is a slow grower and spreads by rhizomes to form extensive colonies over time.
I always wondered if its name, Solomon’s Seal, had some Biblical connection. According to the Perennial Plant Society, the common name Solomon’s Seal can have several origins. The first is that the scar that remains on the rootstock after the leaf stalks die off in the fall resembles the seal impressed on wax on documents in the past.
The second source is that John Gerard, the English botanist and herbalist, suggested that the powdered roots were an excellent remedy for broken bones. He also felt that the plant had the capacity for “sealing wounds,” which was why the perennial received the common name ~ Solomon’s Seal. For more information on this interesting perennial check out the Perennial Plant Society at www.perennialplant.org.
I am excited that spring is just around the corner. We did have a somewhat mild winter, which is a mixed blessing. Because of a lack of an extended cold period, trees and shrubs in the landscape did not experience any winter damage. On the other hand, because our landscapes did not experience those periods of extended cold temperatures we are going to see more insect and weed problems in the garden.
A cold, hard winter goes a long way to kill overwintering garden insect pests, both in the adult and juvenile forms. And a lack of a hard freeze in the soil will result in more weed seeds remaining viable and ready to germinate when the spring temperatures reach the right levels. So, be prepared!
If you did not do a good clean up last fall, get a jump on the weeds now by cleaning up flower beds and any remaining overwintering dead weeds in the vegetable garden so they do not become a seed source. It is too early to lay down any new mulch as you want the soil to warm up to encourage plant growth and get those roots starting to again pump in the nutrients from the soil.
March is a good time, however, to stir up the existing mulch in the landscape beds as it may have settled over the winter. If you wish to commit herbicide and do some chemical weeding there are a couple of pre-emergent herbicides available to the home gardener. You put them down before the weed seeds germinate, but before you use them be sure to read the label completely and apply according to the label directions.
Once your soil has had a chance to thaw and lose some of its winter moisture, you’ll want to prep your vegetable garden for planting. Remove mulch over the course of several days, exposing the soil gradually. Till or spade soil six to 12 inches deep.
Mix in compost and other organic materials. Add lime and fertilizer according to the soil test results. For vegetable gardens, you can include processed or well-rotted ~ not fresh ~ manure in the mix (using fresh manure in the spring may burn or damage your plants). Rake the soil level to smooth out low spots; pockets of water can make the soil cool, which slows plant growth.
Cool season vegetable crops like potatoes, onion sets, onion seedlings and peas can be planted as soon as the soil can be lightly worked. Chinese cabbage, leeks, beets, parsnips, chard, kale, mustard greens and turnips can also be planted now.
Start sowing spinach and lettuce seed outdoors in cold frames for transplanting. You can also start sowing seeds of spinach, lettuce, kale, mustard, sorrel, corn salad and other greens toward the end of the month.
Look for the broccoli and cabbage transplants in the garden center if you did not start your own from seed. These cole crops can also be planted at the end of March.
Consider purchasing some floating row cover material to protect vegetable crops against insects and to promote early growth. Floating row covers are made from a spun-bonded polyester material and are available from mail-order seed and garden supply companies.
Early March is a great time to do some pruning of trees and shrubs in the landscape. For roses, a correct pruning will give them a more attractive shape and also result in larger blooms and longer stems. When you are pruning roses, try to make your cuts just above any outside buds to encourage new outward growth. This will open up the plant and expose it to more sunlight and air.
Non-flowering trees and shrubs can be pruned before new growth appears and when the worst of the winter weather is over. Do not prune spring flowering trees and shrubs at this time as you will be pruning out the flower buds. Wait until the azalea, rhododendron, lilac, forsythia and other shrubs have completed their flowering cycle before pruning.
From early March into April is a great time to plant fruit trees and berries. Just be sure they have enough water as they get used to their new neighborhood.
In addition to zone-specific perennial vegetables, set out or plant new roses and cool-loving flowers such as snapdragons and pansies.
As temperatures warm up, look out for the slugs. These guys have overwintered and are ready to move about and start feeding on the tender foliage of the plants that you have set or the seeds that have just germinated.
Your first line of defense is a good offensive approach in cleaning up of overwintering plant debris, any boards that might be lying around as well as any flower pots or other containers that may have been left out in the garden or landscape over the winter. These slimy plant destroyers like to hide under this stuff for protection and then come out at night to do their feeding.
As with much garden damage control, natural methods are growing in popularity. One simple approach is to sprinkle slugs with salt, which causes them to dry up. Slugs are attracted to stale beer, which you can leave in a shallow dish or bowl; slugs will enter and drown. Or you can gather slugs at night by hand, armed with a flashlight, something to lift them with and a can in which to dispose of them into their final resting place in the trash. There are commercial slug baits available. Be sure to read the label carefully to be sure it won’t endanger children, pets or birds.
March is the beginning of the planting and transplanting season for woody landscape trees and shrubs, as well as herbaceous perennials. A huge selection of plants is now available at the garden center for your selection.
Avoid working with wet soil; wait until the soil dries, especially with the heavy clay soils. Common planting mistakes include planting in compacted or poorly drained soil, planting too deep and buying damaged plants with poor root systems.
Over-mulching can also be a problem. Mulches should be applied only 2-3 inches deep around ornamental plants and kept away from direct contact with shrub and tree trunks. Mature trees do not benefit much from being mulched except to provide a protective barrier around their trunks from lawn mower damage.
It is still too early to set out tender annuals (impatiens, marigolds, petunias, salvia, etc). Wait until after the last frost date so you do not rush the planting. The last average last frost date in the Mid-Shore area usually occurs sometime in the third week of April.
I have noticed that fall planted pansies have not fared very well over the winter, so now would be a good time to replace them with a spring planting to provide color up until June.
Happy gardening!

Marc Teffeau is the Director of Research and Regulatory Affairs at the American Nursery and Landscape Association in Washington, D.C. He lives in Preston with his wife, Linda.