March garden tasks: Southeast
March in the Southeast is the busiest garden month of the year. Zones 7--9 cover a wide range -- from coastal Virginia (zone 7b, last frost March 20) to coastal Florida (zone 10, frost-free year-round) -- but across this band, March is when spring planting accelerates sharply and the gardening.
—- title: "March garden tasks: Southeast" slug: march-garden-tasks-southeast hub: care category: "Monthly tasks" description: "Southeast garden tasks for March — warm-season transplanting, summer crop planning, lawn green-up management, and pest monitoring in zones 7–9." date: 2026-06-10 updated: 2026-06-10 author: "Thomas A." reading_time: 7 zones_min: 7 zones_max: 9 —-
March in the Southeast is the busiest garden month of the year. Zones 7—9 cover a wide range — from coastal Virginia (zone 7b, last frost March 20) to coastal Florida (zone 10, frost-free year-round) — but across this band, March is when spring planting accelerates sharply and the gardening calendar is the most compressed.
Per Clemson HGIC, the last average frost dates for key Southeast cities: Raleigh NC March 24, Charlotte NC March 21, Columbia SC March 16, Atlanta GA March 13, Nashville TN March 17. Coastal areas (Wilmington NC, Savannah GA, Charleston SC) are frost-free by early March in most years.
Warm-season vegetable transplanting (zones 7b—8)
Per NC State Extension, timing for setting out warm-season transplants after last frost:
- Tomatoes: set out after March 20—25 in zone 7b; after March 10—15 in zone 8a. Use transplants grown 6—8 weeks prior.
- Peppers: slightly later than tomatoes — wait until nights are consistently above 55°F; typically late March in zone 8a
- Squash and cucumbers: direct seed or transplant late March in zone 8; these germinate and grow fast enough that direct seeding is often preferred over transplants
- Beans: direct seed after March 15—20 in zones 7b—8; soil temperature 60°F minimum
Per Clemson HGIC, zone 7b (Charlotte, Raleigh) gardeners should wait until late March for tomato transplants. Zone 8 (Columbia SC, Atlanta) gardeners can safely plant after March 10—15 in most years.
Cool-season crops finishing
March is the last chance for cool-season crops in most of zone 8. Per NC State Extension, cool-season crops (lettuce, spinach, broccoli, kale) bolt and become bitter once temperatures consistently exceed 80°F — which typically happens in April in zone 8 and in late March in zone 9.
March priorities for cool-season crops:
- Harvest aggressively — don't leave crops to bolt
- Make one final sowing of fast-maturing lettuce (45-day types like 'Black-Seeded Simpson') for a last spring harvest
- Remove finished broccoli plants and prepare beds for warm-season crops
Starting tomatoes and peppers from seed (late-season zones)
If you haven't started tomatoes indoors in zones 7—8, March is effectively too late for indoor seed starting — you'd be setting out underdeveloped transplants. Per Clemson HGIC, purchase transplants from a garden center and choose varieties that fit the 90-day window between last frost (March 15—25) and first high-heat slow-down (June—July). Short-season hybrids under 75 days work best.
Lawn care in the Southeast
Warm-season lawns (Bermuda, zoysia, centipede, St. Augustine):
Per Clemson HGIC:
- Bermuda and zoysia begin active growth when soil temperature reaches 65°F (typically mid-March in zone 8)
- Apply pre-emergent herbicide before crabgrass germination (soil temp 55°F) — typically early March in zone 8
- First fertilization of the season: wait until lawn is at least 50% green; premature fertilization in cool soil produces lush growth susceptible to disease and late frost
- Centipede and St. Augustine lawns should NOT be fertilized before green-up is complete — per Clemson, applying nitrogen to dormant centipede causes surge growth that depletes root reserves
Per NC State Extension, for bermudagrass: do not fertilize before April 15 in zone 7b; delay until early April in zone 8 if nighttime temperatures are still below 50°F regularly.
Pest and disease scouting
March is the time to establish monitoring habits before pest populations build. Per Clemson HGIC, key March pests and diseases in the Southeast:
- Fire ants: bait early in March before colonies build summer numbers; Amdro or spinosad-based baits are effective at 70—80°F soil temperature
- Scale insects on woody ornamentals: March is the correct timing for dormant/horticultural oil applications before new growth emerges — kills overwintering scales; per NC State Extension, horticultural oil should be applied when temperatures are above 40°F but below 90°F and rain is not expected for 24 hours
- Bagworms on conifers: March is when eggs overwinter in bags from last season; remove and destroy bags before eggs hatch in late April
Pruning in March (Southeast)
Per Clemson HGIC:
- Ornamental grasses: cut back by February—March before new growth emerges
- Roses: prune hybrid teas in February—March in zones 7—8; Knock Out and shrub roses can be cut back by one-third in March
- Spring-blooming shrubs (azalea, forsythia, loropetalum): DO NOT prune until immediately after bloom — flower buds are already set
- Crape myrtle: if not already done, March is acceptable for pruning; per Clemson HGIC, crape myrtles should be pruned only for structure — never "crape murder" (topped or sheared); if you must prune, remove only weak interior growth and crossing branches
Common mistakes in the Southeast in March
| Mistake | Consequence | Correct approach |
|---|---|---|
| Fertilizing warm-season lawn before green-up | Disease surge; late frost damage | Wait until 50% green |
| Setting out tomatoes before last frost | Frost-killed plants | Check zone-specific last frost date |
| Pruning azaleas in March | Removes this spring's flowers | Prune immediately after bloom |
| Topping crape myrtles | Ugly regrowth; reduced flowering | Remove only interior/crossing growth |
Frequently asked questions
Can I plant summer vegetables in March in Florida (zone 9—10)? Per UF IFAS Extension, Central Florida's spring vegetable window is actually February—March. By April, temperatures push above 90°F regularly and tomato fruit set stops. In South Florida (zone 10), spring tomatoes go in January—February. March is the last practical month for spring crops in zone 9.
When should I apply fertilizer to centipede grass? Per Clemson HGIC, do not fertilize centipede before it is fully green (typically mid-April in zone 7b, early April in zone 8). Centipede requires less nitrogen than other warm-season grasses — 1 lb nitrogen per 1,000 sq ft per year total. More than this causes decline and thatch buildup.
When is the right time to overseed a bare spot in a bermuda lawn? Per NC State Extension, bermuda establishes from seed only when soil temperature reaches 65°F consistently — mid-spring (late April—May in zone 7b). March seeding will fail in most years because soil is too cool for germination.
Recommended gear: Best evergreen and deciduous azaleas by zone — our buyer's guide covering picks for every budget, ranked by Extension publication consensus and personal use.
Sources
- Clemson HGIC — Planting Dates for Vegetables
- NC State Extension — Vegetable Planting Calendar
- Clemson HGIC — Lawn Care Calendar
- NC State Extension — Turfgrass Management
- UF IFAS Extension — Florida Vegetable Gardening Guide