What to plant in September in Oklahoma
In Oklahoma (OK), September sits about 7 weeks before the average first fall frost (November 1). The state averages 214 frost-free days a year (last frost April 1, first frost November 1; USDA zones 6b, 7a, 7b, 8a).
21 crops have a sowing or planting window this month, including beet, cilantro / coriander, bok choy / pak choi, borage, dill, fava bean (broad bean) - and 12 of those windows close during September.
Dates here come from Oklahoma frost dates (last frost Apr 1, first frost Nov 1). For one crop in detail, see when to plant beet, lettuce or spinach in Oklahoma.
Oklahoma: planting activity through the year
Last chance in September
Beet (sow for a fall crop, by Sep 6) · Cilantro / Coriander (sow for a fall crop, by Sep 6) · Bok Choy / Pak Choi (sow for a fall crop, by Sep 13) · Borage (sow for a fall crop, by Sep 13) · Dill (sow for a fall crop, by Sep 13) · Fava Bean (Broad Bean) (sow for a fall crop, by Sep 13) · Green Onion / Scallion (sow for a fall crop, by Sep 13) · Kohlrabi (sow for a fall crop, by Sep 13) · Lettuce (sow for a fall crop, by Sep 13) · Mache (Corn Salad) (sow for a fall crop, by Sep 13) · Mizuna (sow for a fall crop, by Sep 13) · Rapini (Broccoli Raab) (sow for a fall crop, by Sep 13)
For fall and winter harvests (20)
Sowings counted back from Oklahoma's first fall frost, so the crop matures before the cold - or, for garlic and similar, planted after it.
| Crop | What to do | Window | This month |
|---|---|---|---|
| Beet | Sow for a fall crop | Aug 20 – Sep 6 | Last chance - ends Sep 6 |
| Cilantro / Coriander | Sow for a fall crop | Aug 20 – Sep 6 | Last chance - ends Sep 6 |
| Bok Choy / Pak Choi | Sow for a fall crop | Aug 27 – Sep 13 | Last chance - ends Sep 13 |
| Borage | Sow for a fall crop | Aug 27 – Sep 13 | Last chance - ends Sep 13 |
| Dill | Sow for a fall crop | Aug 27 – Sep 13 | Last chance - ends Sep 13 |
| Fava Bean (Broad Bean) | Sow for a fall crop | Aug 27 – Sep 13 | Last chance - ends Sep 13 |
| Green Onion / Scallion | Sow for a fall crop | Aug 27 – Sep 13 | Last chance - ends Sep 13 |
| Kohlrabi | Sow for a fall crop | Aug 27 – Sep 13 | Last chance - ends Sep 13 |
| Lettuce | Sow for a fall crop | Aug 27 – Sep 13 | Last chance - ends Sep 13 |
| Mache (Corn Salad) | Sow for a fall crop | Aug 27 – Sep 13 | Last chance - ends Sep 13 |
| Mizuna | Sow for a fall crop | Aug 27 – Sep 13 | Last chance - ends Sep 13 |
| Rapini (Broccoli Raab) | Sow for a fall crop | Aug 27 – Sep 13 | Last chance - ends Sep 13 |
| Chervil | Sow for a fall crop | Sep 3 – Sep 20 | Sep 3 – Sep 20 |
| Mustard Greens | Sow for a fall crop | Sep 3 – Sep 20 | Sep 3 – Sep 20 |
| Spinach | Sow for a fall crop | Sep 3 – Sep 20 | Sep 3 – Sep 20 |
| Tatsoi | Sow for a fall crop | Sep 3 – Sep 20 | Sep 3 – Sep 20 |
| Turnip | Sow for a fall crop | Sep 3 – Sep 20 | Sep 3 – Sep 20 |
| Arugula | Sow for a fall crop | Sep 10 – Sep 27 | Sep 10 – Sep 27 |
| Watercress | Sow for a fall crop | Sep 10 – Sep 27 | Sep 10 – Sep 27 |
| Radish | Sow for a fall crop | Sep 17 – Oct 4 | Opens Sep 17 |
Keep sowing (succession)
Repeat sowings of crops already in the ground, for a steady harvest instead of a glut.
- Basil: sow again on Sep 9
Harvesting in September
First harvests expected this month from crops sown or planted on time earlier in the season.
Planting dates for popular crops in Oklahoma
Every crop has its own full-year dates for Oklahoma: indoor start, transplant or direct sowing, and harvest.
Spring bulbs to plant in September in Oklahoma
Tulips, daffodils, hyacinths and crocus are planted in fall, once the soil has cooled and before it freezes. The exact window depends on the state, so our bulb guide quotes what each extension service says.
Fall garden season: September garden jobs in Oklahoma
- The average first frost is November 1, about 7 weeks away. Pick tender crops (tomatoes, peppers, squash, beans) before it, or cover them on cold nights.
- Still time to sow or plant: beet, cilantro / coriander, bok choy / pak choi, borage, dill, fava bean (broad bean). Fast greens and radishes are the safest bets this late.
- Row cover buys 4-6°F of frost protection and weeks of extra harvest - see season extension.
- Pull finished crops and sow a cover crop (cereal rye or crimson clover) into empty beds before the soil gets cold.
USDA zone chart for Oklahoma
Oklahoma spans USDA zones 6b, 7a, 7b, 8a. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average.
Questions gardeners ask
What vegetables can I plant in Oklahoma in September?
21 crops have a window in September: beet, cilantro / coriander, bok choy / pak choi, borage, dill, fava bean (broad bean), green onion / scallion, kohlrabi, lettuce, mache (corn salad) and more. The tables above give the exact dates for each.
Is it too late to plant garlic in Oklahoma in September?
Not too late - it's actually a little early. In Oklahoma the next garlic window opens around November 12: plant in fall, after first frost.
Is it too late to plant tomatoes in Oklahoma in September?
For this year, yes - the tomato windows in Oklahoma have closed. The next step is to start seeds indoors from about February 4.
When is the first frost in Oklahoma?
The statewide average first fall frost is around November 1 and the last spring frost around April 1. Your town can be a week or two either side - look yours up by ZIP code.
What can I harvest in Oklahoma in September?
From plantings made on time: luffa (loofah gourd), peanut, chayote, zucchini / summer squash, cucumber, broccoli, cauliflower, cabbage, bush bean, kale.
What to plant in September in other states
Dates are computed from Oklahoma’s statewide average frost dates (from NOAA/NCEI climate normals) and each crop’s timing in our crop database. Your garden may be a week or two either side - for dates tuned to your ZIP code, use the planting calendar.