March 2024 Gardening Tips
David Hillock, Senior Extension Specialist
Oklahoma Cooperative Extension Service
Division Of Agricultural Sciences and Natural Resources
- Lawn & Turf
- Remove excessive thatch from warm-season lawns. Dethatching, if necessary, should precede crabgrass control treatment. (HLA-6604)
- Broadleaf weeds can easily be controlled in cool-season lawns at this time with post-emergent broadleaf herbicides. (HLA-6421)
- Preemergent crabgrass control chemicals can still be applied to cool- and warm-season turfgrasses. Heed label cautions when using any weed killers near or in the root zone of desirable plantings. (HLA-6421)
- March is the second-best time of the year to seed cool-season turfgrass; however, fall is the best time to plant. (HLA-6419)
- Cool-season lawns such as bluegrass, fescue, and ryegrass may be fertilized now with the first application of the season. Usually, four applications of fertilizer are required per year, in March, May, October, and November. (HLA-6420)
- Begin mowing cool-season grasses at 1½ to 3½ inches high. (HLA-6420)
- Tree & Shrubs
- Prune spring flowering plants, if needed, immediately following their bloom period.
- Plant evergreen, balled and burlapped, and bare root trees and shrubs.
- Anthracnose control on sycamore, maple, and oak should begin at bud swell. (EPP-7634).
- Diplodia Pine Tip blight control on pines begins at bud swell.
- Chemical and physical control of galls (swellings) on stems of trees should begin now. (EPP-7168 & EPP-7306)
- Dormant oil can still be applied to control mites, galls, overwintering aphids, etc. (EPP-7306)
- The first generation of Nantucket Pine Tip Moth appears at this time. Begin pesticide applications in late March. (EPP-7306)
- Control Eastern tent caterpillars as soon as the critters appear.
- Flowers & Vegetables
- Cultivate annual flower and vegetable planting beds to destroy winter weeds.
- Apply mulch to control weeds in beds. Landscape fabric barrier can reduce the amount of mulch but can dry out and prevent water penetration. Thus, organic litter makes the best mulch.
- Prune roses just before growth starts and begin a regular disease spray program as the foliage appears on susceptible varieties. (HLA-6403 & EPP-7607)
- Avoid excessive walking and working in the garden when foliage and soil are wet.
- Start warm-season vegetable transplants indoors.
- Divide and replant overcrowded, summer and fall blooming perennials. Mow or cut back old liriope and other ornamental grasses before new growth begins.
- Your cool-season vegetables like broccoli, cabbage, carrot, lettuce, onion, peas, spinach, turnips etc. should be planted by the middle of March.
- Watch for cutworms that girdle newly planted vegetables during the first few weeks of establishment. Cabbage looper and cabbageworm insects should be monitored and controlled in the garden EPP-7313).
- Fruits