Just when we think that spring has arrived at the end of April we still get some very cool nighttime temperatures that we are currently experiencing. But hopefully, after this last cold front moved through on Tuesday, consistently warmer temperatures, especially in the evening and night will now become a norm. No wonder the poet T.S. Elliot in his poem The Waste Land once wrote “ April is the cruelest month, breeding Lilacs out of the dead land …”
With the warmer temperatures of April come the insects. One insect pest that we always see is the Eastern tent caterpillar. Found in webs in the branch crotches of fruit trees, especially wild cherries, these white nests can contain hundreds of hungry caterpillars. Although they can defoliate wild cherries, they are not a serious pest.
If control is wanted, you can simply pull the nests down from the small trees or blast them apart with a forceful stream of water from the garden hose. DO NOT try to burn them out of the tree. Another useful control is to spray them with oil spray or Bacillus thuringiensis (BT). BT is a naturally occurring bacterium that is sold as Dipel and gives effective control when applied when the caterpillars are very young. It is also great on bagworms, which appear later in late May. The key to control is to apply BT early when the critters are small.
Give some attention to the spring-flowering bulbs in the landscape. Observe your daffodil and other spring bulbs while in bloom this spring to be sure they have not been shaded by the new growth of other trees or shrub plantings. If they have, you may need to move your bulbs to a new, sunny location or prune back the tree or shrub plantings to allow for more light exposure. Label the clumps of daffodils that are too crowded, as overcrowding inhibits blooming. Dig up and separate in July. Store the bulbs in a cool, dry location and replant in the fall.
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 big bulbs capable of reflowering. To keep the planting going, you can fertilize bulbs upon the emergence of foliage with a 10-10 -10 fertilizer, using a rate of 1 to 3 pounds per 100 square feet. Repeat the application after the bulbs have bloomed.
I noticed this week that the hummingbirds have now returned. It is interesting to watch them at the feeder, especially if there are two or more. You would not think that this delicate little bird would be such a tremendous fighter, being very territorial about who can feed at the feeder! Why watch WMA events on Cable when you can see them in nature!
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, redbud, and tulip poplar. Shrubs include azalea, beauty bush, coralberry, honeysuckle, lilac, New Jersey tea, and red weigela.
Late April is a good time to plant dahlia tubers in the flowerbed. Stake or provide support for the emerging foliage and blooms at the time of planting to avoid injury to tubers. If you dug up and stored dahlia tubers over this winter, one easy way to determine if they have survived storage is to sprout them indoors in a warm, lit spot. Fill the bare spots in the flowerbed with moss roses Portulaca and feed regularly to encourage blooms into the summer.
In April chrysanthemums pop up in the flowerbed. Lift, divide, and replant chrysanthemums 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. Planted now, Sedum spectabile and Hosta tardifolia or H. plantaginea will brighten your flowerbed in the fall with flowers. Aster novae angliae, which is a blue aster or the red chrysanthemum cultivar ‘Minn Ruby’, are also late blooming. Happy Gardening!