Tidewater Gardening - March 2008
K. Marc Teffeau, Ph.D.
Director of Research and Regulatory Affairs American Nursery and Landscape Association
Since I retired from the University of Maryland and joined ANLA, for the past four years I spend five days in mid February in beautiful downtown Louisville, Kentucky. Our ANLA Management Clinic, the premier educational and networking event for the nursery and landscaping industry is held at the Galt House Hotel and Conference Center. Close to 1,000 nursery crop growers, landscape designers, garden center owners and employees attend this event each year.
One of the activities at the Clinic is the NMPRO New Plant Pavilion. Sponsored by a major trade press publication, this event features a display of more than 40 hot new herbaceous and woody plants that are being released to the general public. The Clinic attendees are invited to vote on what they think should be the new plant for that year. In cruising the plants in the competition this year, three peaked my interest.
J. Frank Schmidt and Son, a major tree breeder and liner grower in Oregon is offering a new elm for the landscape. Emerald Sunshine® Elm, Ulmus propinqua ‘JFS-Bieberich,’ was grown from seed collected in China. It has been used successfully on the arid plains of western Oklahoma so it should do well on the Eastern Shore. It matures smaller than most elms (about 30 feet) with a spread of about 25 feet. It has the vase shape that we associate with the American elm but is tolerant of Dutch elm disease and Phloem Necrosis, two disease problems of elms that we have in our area. It also shows good resistance to the elm leaf beetle. Emerald Sunshine® Elm has deep green foliage during the growing season and somewhat dull yellow fall coloration. The fall coloration is not unusual as elms are not generally known for their vibrant fall colors as compared to, let’s say, a red maple.
If you are looking for new perennials to grace your flower border, you might want to try Astilbe ‘Delft Lace’ and Echinacea ‘Pink Double Delight.’ Astilbes are neat perennials that are a great addition to the perennial bed. ‘Delft Lace’, from the Netherlands, was discovered as a seedling of unknown origin and then bred by AB-Cultivars. This Astilbe has deep blue-green, waxy foliage that is covered with a silver-lacy overlay. Its peach colored blooms are held high above the foliage on candy apple red stems. The flower buds emerge deep salmon-pink and open to a soft apricot-pink. It does well in full to part shade in average garden soil and prefers a moist but well-drained site to get established.
‘Delft Lace’ has no known insect or disease problems and it grows 12 to 15 inches tall by 24 to 36 inches wide, so give it some space in the flowerbed. You can plant this Astilbe in shady foundations, mass plantings, commercial landscapes, city gardens and it does great as a specimen container plant. It should be available at your local independent garden center or retail nursery after June 1st.
Another perennial introduction from the AB-Cultivars breeders in the Netherlands is the Echniacea ‘Pink Double Delight.’ It will do well in our area as a key plant in the perennial border. The plant reaches a maximum height of about two feet and starts to flower in July and continues for eight to 12 weeks. It has a shorter growth habit than the typical Echniacea plant and is very floriferous, producing numerous, straight and very sturdy flower stems. The flowers themselves are dainty with a bright, clear pink color and are very long lasting.
Like most E. purpurea, the cone develops from the bottom up, until all ray petals have developed, producing a full, pompom-like bloom. To keep the plant flowering, deadheading is recommended. Removing the spent blooms may extend the flowering period and give the plant a neater look.
March is an excellent time to plant pansies. They are an excellent cool-weather, spring crop. Pansies provide color early, before most bedding plants can be set out. Pansies and their ancestors, violas, have a history that dates back at least as far as the 4th century B.C. Long cultivated in Europe, pansies were bred in England in the 1800s.
There are a wide variety of pansy color choices. Colors include red, purple, blue, lavender, bronze, pink, apricot, orange, white, yellow, black and mahogany. The flowers may be of a single color, call “clear,” or two or three colors with a “face.” Some pansies have a noticeable fragrance - the yellow and blue flowers seem to be the most aromatic, often giving off the strongest scent at early morning and dusk.
The pansy plant itself is compact, not more than 9 inches tall and wide, exhibiting many stems with attractive oval- or heart-shaped leaves. Grown as annuals, in our area, pansies thrive in cool weather and will tolerate a light frost and cold night temperatures. Newer varieties are bred to withstand some heat stress.
When buying pansy transplants, choose stocky plants with dark-green foliage and few blooms but many buds. Pansies grow best in a well-drained soil that receives morning sun.
Before planting, water the plants in their containers. This makes it a lot easier to remove the plant without damaging the roots. Loosen the soil in the bed and plant the pansies 6 to 10 inches apart. Be sure to water them in. If you want to give them a little “kick-start,” water them in with a liquid fertilizer solution such as Miracle Grow or Rapid Grow at the recommended rate for fertilization of annual flowers.
In the vegetable garden peas, radishes, onions, spinach, turnip greens and collards will all grow well in cool soils, which means they can be planted towards the end of March. Other cool season crops include broccoli, cauliflower, kale, and cabbage. Potatoes and salad vegetables, such as lettuce and carrots, round out the cool-season planting efforts.
March is the time to plant peas and potatoes in the vegetable garden. In addition, you can seed spinach later on in the month as it does well in cool weather.
Now is the time to check for frost heaving in the perennial garden. This is likely to occur in gardens that weren’t mulched last fall, but it may even happen in mulched sites.
Because of freezing weather, ice can form in the soil under the plants in winter and can literally push them out of the ground. This exposes the crown of the plants and roots to the harsh temperatures and drying winds. If you have any frost heaved plants, gently “tramp” them back in the ground. To do this, carefully place your foot along side each plant and firmly step down, pushing it back into the ground and packing soil around its roots.
Next, look under mulched perennials to see if their crowns are showing new green growth. If they are, it’s time to loosen the mulch. Don’t remove it yet however. Delay the removal of the mulch until the chance of extended below freezing weather has passed. When you do remove the mulch, be sure to cut back the old flower stems and remove dead leaves. Dispose or compost them rather than leaving them lying in the garden.
Early spring is an excellent time to fertilize perennials. Use a balanced fertilizer like 5-10-5 that is higher in phosphorous than nitrogen, or a slow release organic fertilizer with a 1-2-1 ratio. You want good flower production and not an over abundance of foliage. Scatter a handful or more of this fertilizer around each plant and water it in. Make sure that any fertilizer in the center of the plants or on newly exposed foliaged is washed off to reduce burn. If you have a fireplace or woodstove, the wood ashes are an excellent fertilizer for perennials providing them with a quick release source of potash. Apply them like you would the fertilizer. In addition, if you have any early spring slug problems, wood ashes tend to discourage these leaf munchers because of the ash’s caustic nature.