OKLA. CITY —
Most bedding plants and summer flowering bulbs, such as gladiolus and dahlias can be planted after danger of frost. This happens around mid-April in most of Oklahoma. Annual flower seeds also can be planted.
Let spring flowering bulb foliage remain as long as possible before removing it. The foliage is necessary to produce next year’s flowers. Leaf spot diseases can cause premature death of foliage and reduce plant vigor.
Warm season lawn planting begins now. Hybrid bermudagrass, zoysiagrass or St. Augustine grass must be started vegetatively. St. Augustine is adapted only in the southern border counties. Sprigs, plugs or squares of sod laid solid can be used. In southern Oklahoma, bermudagrass can be seeded, but a more permanent lawn results from vegetative planting. Buffalo-grass and Oklawn-centipede grass can be seeded.
Warm season grasses can be fertilized four times per season using one pound of actual nitrogen per 1,000 square feet. Apply 1 pound in April, May, June and September. If phosphorus and potassium are adequate as proven by a soil test, make only one application of complete fertilizer such as 18-5-9. Five pounds of 18-5-9 gives one pound of a.i. nitrogen. Thereafter, apply two pounds of urea or three pounds of ammonium nitrate per 1,000 square feet. Water-in nitrate fertilizers. Cutting height for bermuda, buffalo and zoysia should be 1-inch to 1 1/2 inches high. All others should be 2-3-inches high.
Softwood cuttings from new growth of many shrubs will root if propagated in a moist shady spot. Rooting compounds/hormones will greatly increase success rate.
Be alert for both insect pests and predators. Some pests can be hand picked without using a pesticide. Do not spray if predators such as lady beetles are present. Spray only when there are too few predators to be effective.
Remove any winter-damaged branches or plants that have not begun to grow. Waxleaf privet and Euonymus are frequently damaged by cold.
Keep dividing perennials. Division not only rejuvenates some perennials, but also is an economical way to stretch perennial purchases from nurseries.
Remove tree wrap from young trees so that the bark doesn’t stay moist and rot.
Spring blooming shrubs such as forsythia and flowering quince should be pruned shortly after bloom.
Trim evergreens after new growth begins to expand. Don’t prune back into woody stems.
RAY RIDLEN is an agriculture/horticulture educator for the Oklahoma County OSU Extension Service, 930 N. Portland, in Oklahoma City. For more information, call him at 713-1125.
If you Go
The following workshops will be at the OSU Extension Center, 930 N. Portland in Oklahoma City, unless otherwise specified. They are free and open to the public. For more information, call 713-1125.
• 1:30-3 p.m. April 16 — Lawn Management
• 5:30-6:30 p.m. April 18 — Third Thursday Gardening: Perennials and Annuals