April 2012 Gardening Calendar
This is a special column provided to all readers. Find Calvin Finch's regular column in the Wilson County News every week.
April is a busy month for gardening. The first thing you can do is to remove the wintering plants from the greenhouse. Bougainvilleas, oriental hibiscus, mandivilla, pentas, purple fountain grass, and the other cold sensitive plants respond well to the mild weather of April. Prune them up to remove dead wood and stimulate new growth.
Support the new growth with Osmocote or hibiscus food. If you wintered plants in the greenhouse they may have aphids, whiteflies and weeds that have developed. The usual weed in my greenhouse is chickweed. It is easy to pull. Pull it up before you move the plants to their place on the patio. As for the insects they will probably disappear after you move the plants out of the greenhouse. The wind, more severe temperature fluctuations, and predatory insects may be all that is required. If not, aphids can be controlled with Spinosad, Safer Soap or even a water spray. You may have to use acephate for the whiteflies on the ornamental plants.
You can also place the potted-up tomatoes in the garden and obtain new plants from the nursery to place directly in the garden. The recommended varieties are Tycoon, BHN 602, BHN 968, Celebrity, Phoenix, Merced, Solar Fire, and Sun Pride.
For gardeners that want to grow tomatoes in containers consider BHN 968. It is also called the “Rodeo Surprise Dwarf Tomato.” It produces a beautiful supply of large cherries on a relatively small plant. Grow it and other tomatoes in 10 gallon or larger containers. Half whiskey barrels work well.
Even with a whiskey barrel the soil reservoir in a container is limited so they will probably have to be irrigated every day. Fertilize with Osmocote and soluble fertilizer formulated especially for containers.
In the flower garden the roses should be blooming at their best. Support the blooms with a half cup of slow release lawn fertilizer (19-5-9) per plant every month and regular irrigation. Control insects with acephate and black spot disease with triforine.
Snapdragons will decline this month but will provide a great show for several more weeks. They can be replaced with zinnias or cosmos. When pansies decline, consider moss roses or purslane. For the shade garden cyclamen can be replaced with caladiums, coleus or begonias. Begonias also do well in the sun if they are planted this month and have time to become established before hot weather arrives.
Vinca is a good flower for sunny gardens in the summer but make sure you find the selection “Cora” so that the plants have resistance to aerial phytophthora. Aerial phytophthora is the fungus disease that melts vinca when it is humid, rainy or when you sprinkle irrigate over the top.
To ensure that the seed is produced for next year’s wildflower crop the plants need to be allowed to mature their seed and brown where they are growing. The “wildflower ugly” period can be disguised by spreading cosmos seed early in the month. Cosmos will bloom and reseed itself all summer.
The winter weeds are finally declining in our lawns. Keep them mowed with the lawn mower and string mower to reduce the seed crop for next year.
When you have mowed real grass twice it is time to fertilize the lawn. Use a slow release lawn fertilizer such as 19-5-9.
Sand burs and crabgrass will be eager to replace the rescue grass and other winter weeds unless you apply a pre-emergent herbicide such as Crabgrass Preventer 2, Weed and Grass Stopper or Amaze early in the month.
It may be too late to protect your peaches, plums, and apples from stink bugs and other insects unless you have been spraying every 1 to 2 weeks with Sevin and Malathion, but if you have, keep the spray program up.
Even though many of the wintering birds will be heading back North this month there is lots of action at the feeders as they move through. American goldfinches often wait until May, keep their thistle feeder full. Hummingbirds should be obvious in the landscape if you have cross vine, Salvia greggii, pentas, zinnias, columbines, and other flowers blooming. Make them even easier to observe by hanging 1 or 2 sugar water feeders off the eaves or arbor on the patio.
Calvin R. Finch, PhD, is a SAWS Director and Horticulturist. Find his regular column, "Gardening in South Texas," in the Wilson County News each week.