Tidewater Gardening - May 2010


Spring Moves Forward
K. Marc Teffeau


Ah, glorious Spring! The warmer than usual spell we had in early April pushed flowering trees and shrubs up a little in their floral display. Fortunately, even with all the nasty weather we had this past winter, it was not unseasonably cold, so the flower buds came through without much damage. The azaleas, crabapples, deciduous magnolias, flowering cherries, flowering pears, forsythia and lilacs were beautiful this spring.
I made the annual pilgrimage down to see the cherry blossoms at their peak around the Tidal Basin in D.C. during my lunch hour. Besides the cherry blossoms, another sign of spring in D.C. are the tourists on the METRO, milling around in herds, gawking at the METRO rail map, kind of like Indiana Jones searching for the lost temple of the Smithsonian.
Lots of activities in the garden and landscape now! And, the older I get, he more those activities are accompanied by sore muscle creams and aspirin, especially since I am using many formerly dormant muscle groups. But it is all worth it.
Now’s the time to get working on pruning the spring flowering trees and shrubs. May is the best time to do this since they will start setting their next year’s flower buds in August and September. Any dead branches that were caused by the heavy snow falls should be evident by now, so prune them out.
If you have overgrown forsythia, flowering almonds and spireas you can cut them back to a third of their original size and they will re-grow. Selectively prune lilacs, removing old and diseased stems first as they are very poor flower producers. As compared to cutting some spring shrubs back to a third, for lilacs I recommend selective pruning of no more than one-third of the total bush at any one time.
For the fruit trees in the garden, you can selectively prune out dead and diseased branches after flowering. Do it carefully, however, so as to not knock off any flowers that have set fruit.
I am always on the lookout for new flower introductions, and there are new annual and new perennial cultivars that you might want to try. Renee’s Garden – www.reneesgarden.com – has a new Cosmos (Cosmos bipinnatus) that is unique. Rose ‘Bon Bon Cosmos’ is a free-flowering, long-blooming cultivar that will be great for cut flower use.
Cosmos have a somewhat “dainty” characteristic to it and these rose-colored flowers enhance that appearance. This cultivar, developed by French breeders, produced three-inch flowers that bloom non-stop on long stems, making them excellent for cut flower bouquets all summer long. In fact, according to Renee’s Garden, continuous cutting will encourage season-long flowering.
These flowers also attract butterflies making it a good addition to the butterfly garden. This cosmos will bloom until the first frost and is tolerant of a wide variety of soils. Make sure you plant it in a full sun exposure.
I have written about Gaillardia’s before. These heat-tolerant perennials are an excellent addition to an Eastern Shore perennial bed. Ball Horticulture has introduced new solid yellow Gaillardia, Gaillardia x grandliflora ‘Mesa Yellow.’ This perennial is a Fleuroselect Gold Medal winner for 2010 (Fleuroselect being a European flower judging organization).
According to Fleuroselect, ‘Mesa yellow’ is a first-year flowering perennial which is drought-tolerant and has a long flowering season. The common name for Gaillardia is Blanket Flower. This is because of the flowers’ resemblance to brightly patterned blankets made by native Americans and the species is native to the crescent of dry grasslands that stretch from the Prairie Provinces of Canada to Arizona.
The native plants form wiry branched stems with lanceolate to linear basal leaves and bright daisy-like single color and bicolored blooms in shades from buff to red to brown. Cultivars have broadened the color pallet to include a range of hues from peach to apricot to yellow. There are more than two dozen known species of Gaillardia. Most commercially available cultivars have Gaillardia x grandiflora in their genetic background.
Anxious to get the vegetable garden beds planted? Last year, sales of vegetable plants, seeds and related materials made a major jump as folks were getting back to growing their own food. So far, that trend has continued this year. The soil is warming up and the last frost date has passed so we can get to some of our spring plantings.
In the vegetable garden it is time to make your first sowing of green beans, cucumbers, squash, sweet corn and a second seeding of lettuce. Transplants of tomatoes, eggplants and peppers can now be placed in the garden.
To prevent cutworm damage on the transplants, cut the tops and bottoms off the small-size coffee cans. Place the cans over the transplants in the early evening. Next morning, remove them so the plant can get full sunlight. Repeat this practice for about a week until the plants become established. A tell-tale sign that you have cutworms in the garden is pencil-diameter-sized holes in the ground. The cutworms come out at night and clip the transplants off at ground level.
Other early spring insect pests active now include aphids, cabbagworms, squash bugs, cucumber beetles and Colorado potato beetles. Aphids seem to appear overnight and suck the sap from the leaves and tender new growth, but usually cause little permanent damage. Usually, a number of parasites and predators, notably the ladybird beetle, help keep this insect pest in check. A forceful spray from the garden hose will help to keep aphids under control. For serious infestations, try using a soap insecticide.
Keep an eye out for cabbageworms in the cabbage and broccoli plantings. They can ruin the heads if not kept under control. How many times have you gone out to the vegetable garden, picked a couple of nice heads of broccoli, brought them inside and steamed them for dinner, only to find a couple of blanched white cabbageworms on the dinner plate? Don’t worry, the cabbageworms are a source of protein, but most of us prefer being served protein in the form of a steak. Use a biological control called B.t. or Dipel to control these worms.
Striped and spotted cucumber beetles are voracious feeders on many vegetables including squash, corn, cucumbers, melons and beans. They also transmit the bacterial wilt disease that causes the plants to rapidly wilt and die.
These beetles must be controlled early with floating row covers. Protection in the early stages of growth is important, however, when the plants start to flower you will need to remove the cover to allow bees access to pollinate the flowers.
Try using a homemade spray of horseradish roots and leaves, garlic, peppercorns, hot peppers and green onions. Blend these ingredients up in your blender and then place in a pail and add one cup of liquid detergent. Stir and let sit overnight. Use one-half cup of the solution to one quart of water and spray on the plants.
Squash bugs are a real pain, so you need to get on them as soon as you see the tiny bugs present. Concentrate on looking for them at the base of the squash plants.
Spring lawn care usually consists of mowing the lawn at the proper height with a sharp blade. Mow the lawn at least 2½ to 3 inches tall. The taller mowing height will help keep the crabgrass under control by not letting the sunlight hit the soil surface where the crabgrass seed lies. Crabgrass needs sunlight to germinate.
If you are replacing an old lawn mower, buy one that mulches the grass clippings and returns them to the lawn. This will return the valuable nutrients found in the clippings back to the turf.
I do not recommend fertilizing the lawn in May. If you missed an early spring feeding, wait until fall. Do not fertilize cool-season turf during the summer.
In the flower garden, now is the time to set our marigolds, petunias, ageratums and fibrous begonias. All are good border plants. Multiflora petunias withstand heat much better than other types and are more attractive throughout the summer. They are more resistant than other types to botrytis, a disease the cripples petunias, especially in damp weather. Multifloras branch more easily, meaning less maintenance and they are most useful for massed effects in beds.
You can also set petunia plants among fading tulips or daffodils to hide the unsightly wilting leaves. After the bulb foliage begins to fade, you can tie the leaves in gentle knots to neaten them, but don’t remove them until they have dried completely.
Impatiens are the most satisfactory annual for use in shady areas. Begonias, coleus, ageratum, salvia and vinca prefer light shade (5 to 6 hours of sunlight). If you are looking for plants that flower each year, require little care and are rarely bothered by pests or disease, try some of these perennials: coneflower, bleeding heart, coral bell, day lily, geum, hosta, bergenia, Virginia bluebell and Veronica.
Happy Gardening!!