Tidewater Gardening - April 2012

April Activities

by

K. Marc Teffeau

There’s lots to do in the landscape this month! The warmer-than-normal winter has accelerated the gardening schedule this spring. Spring flower bulb displays appeared earlier than normal. For the daffodils that popped out early, observe them and other spring bulbs while in bloom to be sure they have not been shaded by the new growth of other tree or shrub plantings. If they have, you may need to move your bulbs to a new, sunny location or prune back the plantings.
Label the clumps of daffodils that are too crowded, as overcrowding inhibits blooming. Dig them up and separate them in July. Cut the flower stalks back to the ground on daffodils, hyacinths, and other spring flowering bulbs as the flowers fade. Do not cut the foliage until it dies naturally. The leaves are necessary to produce strong bulbs capable of re-flowering.
April is perfect month to plant pansies in the landscape. A number of newer varieties have heat tolerance bred into them so they last longer in the landscape, lasting through June. You can brighten up your front entryway with pots of transplanted pansies or place them in outdoor beds as soon as the soil can be worked. Purchase large plants that will give a good show before hot weather arrives.
If the warm weather continues, we might be looking at planting annuals in the landscape a week or two earlier than normal. When purchasing bedding annuals this spring, choose properly grown plants with good color. Buy plants with well developed root systems that are vigorous, but not too large for their pots.
Also, when you are out shopping for annual flowers for your garden, look for plants with lots of unopened buds. Plants that bloom in the pack are often root bound and can be set back for several weeks after being transplanted. Plants not yet in bloom will actually bloom sooner, be better established and grow faster.
The same suggestions apply to vegetable transplants such as tomatoes and peppers. Don’t buy a tomato or pepper plant that already has flowers on it or has set fruit. If you do, be sure to remove all flowers and existing fruit before planting. Transplanting fruiting plants will set their production back. You will get a quicker crop by planting non-flowering plants.
Besides buying non-flowering, or limited flowering transplants, there are a few other guidelines. Look for plants that are stocky and are compact in size, not leggy. Make sure the plants have a dark green color and no diseased foliage. Check the undersides of the leaves for whiteflies and the new, succulent stems for aphids. One of the easiest ways to avoid insect and disease problems is to not import them into the garden.
By the way, it’s always a big temptation to rush the planting season in April, especially for warm season crops like tomatoes, peppers, squash and cucumbers. I have heard garden center employees remark about home gardeners asking for tomato transplants the first of March when the temperature got above 60 degrees for one day. If you try to get too much of a jump on the weather by setting out tender plants and seeds now, you are in for nothing but trouble.
The exceptions to this rule are cool season crops like broccoli, cabbage and cauliflower and onions. The average last frost date in Caroline County is April 16th and Talbot, April 17th. This date can vary as much as 5 to 10 days depending upon your location in the county and proximity to a body of water like a river, creek or the Bay. However, it has been my experience over 35 years that we can get a killing frost the first week of May, so be prepared to protect early plants in the garden with a fabric cover, basket or similar covering.
In April, chrysanthemums pop up in the flower bed. Lift, divide and replant them as soon as new shoots appear. Each rooted shoot or clump will develop into a fine plant for late summer bloom. Pinch out the top when the plants are about 4 inches high to thicken the plant. You can also take chrysanthemum cuttings now through mid June for flowers during fall and winter in the greenhouse.
Besides chrysanthemums, many popular perennials can be divided now including phlox, fall asters, Shasta daisies, baby’s breath and liriope. Set up a plant exchange with friends and neighbors to share the excess.
April is the time to plant Sedum spectabile and Hosta tardifolia or H. plantaginea which will brighten your flower bed in the fall. Aster novae angliae, which is a blue aster or the red chrysanthemum cultivar ‘Minn Ruby,’ are also late bloomers.
Now is also the time to do some planning and planting of perennial flower beds. One way to increase the apparent length of your flower borders when seen from inside is to place the majority of the warm and hot colored perennial plants (yellows, oranges and reds) nearest the house. Concentrate the blues, which have a tendency to appear more distant, in the second half of the garden. Along with the blues, include some pink and mauve flowers. Plants with silver foliage can be used to provide a unifying ground color throughout.
The actual dimensions of the borders and the paths separating them can help increase the illusion of distance. In a 20 foot long border, make the planting about 1½ feet narrower and the path about 1 foot narrower at the end away from the house.
If you would like to attract hummingbirds to the flower border this year, plant red or orange flowers. Monarda (bee balm) is a good perennial to provide nectar for these small birds.
Besides planting annual and perennial flowers to attract hummingbirds, think about adding some woody plants to the yard to provide nectar for our smallest native birds. Some common trees visited by hummingbirds are buckeye, horse chestnut, catalpa, apple, crabapple, hawthorn, silk tree, and redbud and tulip poplar. Shrubs include azalea, beauty bush, coralberry, honeysuckle, lilac, New Jersey tea and red weigelia.
April is also a good time to scatter annual poppy seeds in flower borders. The fine seeds need no covering. The plants grow rapidly and provide colorful flowers in early summer.
It is somewhat difficult to find a perennial flower that does well in the shade. For 2012 the Perennial Plant of the Year, Brunnera macrophylla ‘Jack Frost’ PP13859, will fit the bill. This perennial grows 18 inches tall and 18 inches wide in a mounded form. This perennial grows well in hardiness zones 3 to 8. Brunneras are treasured for their shade tolerance and early baby-blue, forget-me-not like flowers.
Brunnera macrophylla ‘Jack Frost’ has enchanting silvery leaves with green venation and a thin green margin. One common name for this perennial is heartleaf brunnera because the emerging leaf enlarges to a heart shape.
Brunneras thrive in the shade but will tolerate morning sun if the soil conditions remain moist. By midday, shade is essential, particularly in southern gardens. This perennial performs best in shady areas with good moisture retentive soils.
‘Jack Frost’ brunnera may be used along the front of the shade border, is excellent in a container, or can be combined with other ground cover perennials such as hostas, ferns, and epimediums. The silver foliage lights up a dark garden from spring to fall. From mid to late spring, blue, forget-me-not like blossoms are held in clusters several inches above the brilliant frosty silver leaves. The rough leaf texture makes this perennial less palatable to browsing deer.
Late April is a good time to plant dahlia tubers in the flower bed. Stake them at the time of planting to avoid injury to the tubers. If you dug up and stored dahlia tubers over this winter, one easy was to determine if they have survived storage, is to sprout them indoors in a warm, lit spot.
Fill the bare spots in the flower bed with Portulaca and feed regularly to encourage blooms into the summer.
In the lawn area, apply a pre-emergent herbicide for crabgrass control. Get the lawn mower out and clean it up - if you didn’t do it last fall before putting it away. Be sure to sharpen the mower blade before using it. And also be sure to cut the turf at the proper height - 2 inches or more.
Prune out suckers and water sprouts from the trees and shrubs in the landscape. Prune the dead canes in the roses back to 3”. All other canes can be pruned back to 6 to 12”. Remove all the debris in the plants. Clean up the iris beds of old dead foliage, flower stalks and diseased rhizomes. This will help to reduce iris borer problems later this spring.
Happy Gardening!