When to plant in Oklahoma
Oklahoma spans USDA hardiness zones 6a-8a. Average last spring frost: early April. Average first fall frost: late October. This calendar is anchored to Oklahoma State University Extension's recommendations, with timing adjusted for the dominant climate zone of the state.
Oklahoma at a glance
| USDA hardiness zones | 6a-8a |
| Region | Great Plains |
| Average last spring frost | early April |
| Average first fall frost | late October |
| Primary Extension service | Oklahoma State University Extension |
What grows particularly well in Oklahoma
These are the crops, ornamentals, and trees Oklahoma State University Extension highlights as well-suited to Oklahoma's climate:
- pecan
- wheat
- tomato
- okra
- redbud (state tree)
- blanketflower
- prairie grasses
Oklahoma planting calendar
Dates are approximate and based on the dominant USDA zone for the state. For zone-specific timing, use the zone finder by ZIP code and frost date lookup tools.
Spring planting (after last frost: early April)
Cool-season vegetables (start 2-6 weeks before last frost outdoors): lettuce, spinach, peas, radishes, carrots, beets, kale, broccoli transplants, cabbage transplants.
Warm-season vegetables (after last frost, soil 60F+): tomato transplants, pepper transplants, beans (direct sow), cucumbers, squash, melons. See the seed starting timeline tool for indoor start dates.
Annual flowers (after last frost): zinnia, marigold, cosmos, sunflower, nasturtium.
Perennials, shrubs, trees: Plant in spring after soil thaws but before summer heat. Best window in Oklahoma: 4-6 weeks after last frost.
Summer (June - August)
Maintenance season for most Oklahoma gardens. Mulch heavily, water deeply (1 inch per week), pinch back mums for fall bloom, hand-pull weeds, harvest summer vegetables. Plant fall vegetable starts indoors by mid-July.
Fall planting (before first frost: late October)
Cool-season vegetables (6-8 weeks before first frost): lettuce, spinach, radish, kale, broccoli, cabbage transplants. Per Penn State Extension, fall vegetable production can equal or exceed spring production with proper timing.
Spring-flowering bulbs: tulip, daffodil, allium, crocus, hyacinth. Plant 4-6 weeks before ground freezes. In Oklahoma: typically October-November.
Perennials, shrubs, trees: Fall is the best planting season for woody plants in most of Oklahoma - cooler temperatures + autumn rains reduce transplant stress. Plant 6+ weeks before first hard freeze.
Garlic: Plant cloves in October-November. Harvest the following July.
Winter (December - February)
Most of Oklahoma is in dormancy. Tasks: order seeds, plan next year, dormant prune fruit trees (February), order bare-root plants for spring delivery. Avoid foot traffic on frozen lawns.
Common Oklahoma challenges
Tornado alley; extreme heat (110F+); drought cycles; clay soil that cracks; ice storms; bagworms; chiggers. For region-specific guidance, see our Great Plains regional gardening guide.
Where to get Oklahoma-specific advice
The most reliable source for local growing advice is your county Extension office. Oklahoma State University Extension has county offices that provide free soil testing, plant disease diagnosis, and growing recommendations specific to your microclimate.
Visit Oklahoma State University Extension for the office nearest you.
Related tools and guides
- Find your USDA zone by ZIP code
- Look up your average frost dates
- Seasonal care calendar by zone
- Seed starting timeline calculator
- Great Plains regional gardening guide