Frost Dates for Duncan, OK 73533
Last spring frost March 30 · First fall frost November 4 · 219 frost-free days · USDA Zone 8a
ZIP 73533 has about 27,600 people.
Long season: 219 frost-free days. Spring frost risk spans March 17–April 13 (27 days). Fall frost risk spans October 18–November 20 (33 days).
Frost probability for 73533
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | April 13 | March 30 | March 17 |
| Fall (first frost) | October 18 | November 4 | November 20 |
Dates come from NOAA 1971–2000 freeze probabilities at WAURIKA (38.1 km away); the 50% date is the median year.
Which crops fit a 219-day season in Duncan
In Duncan (219 frost-free days, a long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Feb 23 | Apr 13–Apr 20 | 177 | fits: 80 days to maturity, 177 available after Apr 13. | Jul 5 |
| Pepper | Feb 16 | Apr 13–Apr 20 | 177 | fits: 75 days to maturity, 177 available after Apr 13. | Jul 10 |
| Lettuce | Feb 2 | Mar 2–Mar 9 | 254 | two-plantings: Plant Mar 2 and again by Sep 13; both mature before Nov 11. | Sep 13 |
| Carrots | — | Mar 9–Mar 16 | 261 | fits: 70 days to maturity, 261 available after Mar 9. | Sep 2 |
| Cucumber | Mar 9 | Apr 13–Apr 20 | 191 | two-plantings: Plant Apr 13 and again by Aug 8; both mature before Oct 21. | Aug 8 |
| Beans | — | Apr 6–Apr 20 | 205 | two-plantings: Plant Apr 6 and again by Aug 15; both mature before Oct 28. | Aug 15 |
| Peas | — | Feb 2–Apr 13 | 282 | fits: 65 days to maturity, 282 available after Feb 2. | Aug 24 |
| Zucchini | Mar 16 | Apr 13–Apr 20 | 191 | two-plantings: Plant Apr 13 and again by Aug 13; both mature before Oct 21. | Aug 13 |
| Onion | Jan 5 | Mar 2–Mar 16 | 254 | fits: 100 days to maturity, 254 available after Mar 2. | — |
| Spinach | — | Feb 2–Mar 23 | 296 | two-plantings: Plant Feb 2 and again by Oct 2; both mature before Nov 25. | Oct 2 |
| Kale | Jan 19 | Mar 2–Mar 16 | 268 | two-plantings: Plant Mar 2 and again by Sep 17; both mature before Nov 25. | Sep 17 |
| Broccoli | Feb 2 | Mar 2–Mar 16 | 254 | fits: 80 days to maturity, 254 available after Mar 2. | Aug 9 |
| Cabbage | Feb 2 | Mar 2–Mar 16 | 268 | fits: 70 days to maturity, 268 available after Mar 2. | Sep 2 |
| Radish | — | Feb 2–Apr 27 | 282 | two-plantings: Plant Feb 2 and again by Oct 3; both mature before Nov 11. | Oct 3 |
| Beets | — | Feb 2–Apr 27 | 282 | two-plantings: Plant Feb 2 and again by Sep 3; both mature before Nov 11. | Sep 3 |
| Potatoes | — | Mar 16–Mar 23 | 240 | fits: 90 days to maturity, 240 available after Mar 16. | — |
| Garlic | — | Nov 4 | 324 | overwinter: Plant Nov 4 to Nov 25; harvest the following summer. | Nov 25 |
| Strawberry | — | Feb 23–Apr 20 | 275 | perennial: A perennial: plant Feb 23; it fruits from the following year and keeps producing for several years. | — |
| Corn | Mar 2 | Apr 6–Apr 13 | 191 | fits: 75 days to maturity, 191 available after Apr 6. | Jul 17 |
| Pumpkin | Mar 16 | Apr 13–Apr 13 | 184 | fits: 100 days to maturity, 184 available after Apr 13. | Jun 22 |
| Cauliflower | Feb 16 | Mar 23–Apr 6 | 233 | fits: 75 days to maturity, 233 available after Mar 23. | Aug 14 |
| Swiss Chard | Feb 2 | Mar 16–Mar 16 | 240 | two-plantings: Plant Mar 16 and again by Sep 3; both mature before Nov 11. | Sep 3 |
| Arugula | — | Feb 2–Apr 27 | 296 | two-plantings: Plant Feb 2 and again by Oct 2; both mature before Nov 25. | Oct 2 |
| Brussel Sprouts | Feb 2 | Mar 2–Mar 16 | 268 | fits: 100 days to maturity, 268 available after Mar 2. | Aug 3 |
| Butternut Squash | Mar 16 | Apr 13–Apr 20 | 184 | fits: 100 days to maturity, 184 available after Apr 13. | Jun 22 |
| Eggplant | Feb 9 | Apr 13–Apr 20 | 177 | fits: 70 days to maturity, 177 available after Apr 13. | Jul 15 |
| Okra | Mar 2 | Apr 6–Apr 13 | 198 | two-plantings: Plant Apr 6 and again by Aug 13; both mature before Oct 21. | Aug 13 |
| Basil | Feb 23 | Apr 20–Apr 20 | 184 | two-plantings: Plant Apr 20 and again by Aug 8; both mature before Oct 21. | Aug 8 |
| Cilantro | — | Mar 2–Mar 23 | 254 | two-plantings: Plant Mar 2 and again by Sep 8; both mature before Nov 11. | Sep 8 |
| Parsley | Jan 19 | Apr 6–Apr 13 | 219 | fits: 70 days to maturity, 219 available after Apr 6. | Aug 19 |
| Celery | Jan 19 | Apr 6–Apr 20 | 219 | fits: 120 days to maturity, 219 available after Apr 6. | Jun 30 |
| Scallions | Jan 19 | Mar 2–Mar 16 | 268 | two-plantings: Plant Mar 2 and again by Sep 12; both mature before Nov 25. | Sep 12 |
| Turnip | — | Mar 2–Mar 16 | 268 | two-plantings: Plant Mar 2 and again by Sep 22; both mature before Nov 25. | Sep 22 |
| Kohlrabi | — | Feb 16–Mar 2 | 282 | two-plantings: Plant Feb 16 and again by Sep 17; both mature before Nov 25. | Sep 17 |
| Bok Choy | Mar 2 | Mar 23–Mar 30 | 233 | two-plantings: Plant Mar 23 and again by Sep 13; both mature before Nov 11. | Sep 13 |
| Collards | Jan 19 | Mar 2–Mar 16 | 268 | two-plantings: Plant Mar 2 and again by Sep 12; both mature before Nov 25. | Sep 12 |
| Cantaloupe | Mar 16 | Apr 13–Apr 20 | 177 | fits: 85 days to maturity, 177 available after Apr 13. | Jun 30 |
| Chives | Jan 5 | Apr 6–Apr 13 | 233 | fits: 90 days to maturity, 233 available after Apr 6. | — |
| Dill | — | Feb 2–Apr 27 | 282 | two-plantings: Plant Feb 2 and again by Sep 3; both mature before Nov 11. | Sep 3 |
| Oregano | Jan 19 | Apr 6–Apr 13 | 233 | fits: 80 days to maturity, 233 available after Apr 6. | — |
| Rosemary | Jan 5 | Apr 6–Apr 13 | 219 | fits: 80 days to maturity, 219 available after Apr 6. | — |
| Sage | Feb 2 | Apr 6–Apr 13 | 233 | fits: 75 days to maturity, 233 available after Apr 6. | — |
| Thyme | Jan 19 | Apr 6–Apr 13 | 233 | fits: 90 days to maturity, 233 available after Apr 6. | — |
| Calendula | Feb 16 | Mar 16–Mar 30 | 240 | two-plantings: Plant Mar 16 and again by Sep 8; both mature before Nov 11. | Sep 8 |
| Cosmos | Mar 2 | Mar 30–Apr 13 | 205 | two-plantings: Plant Mar 30 and again by Aug 8; both mature before Oct 21. | Aug 8 |
| Lavender | Jan 5 | Mar 30–Apr 13 | 240 | fits: 90 days to maturity, 240 available after Mar 30. | — |
| Marigolds | Feb 16 | Mar 30–Apr 6 | 205 | two-plantings: Plant Mar 30 and again by Aug 18; both mature before Oct 21. | Aug 18 |
| Melons | Mar 16 | Apr 13–Apr 20 | 177 | fits: 85 days to maturity, 177 available after Apr 13. | Jun 30 |
| Mint | — | Mar 30–Apr 13 | 240 | fits: 90 days to maturity, 240 available after Mar 30. | — |
| Nasturtiums | Mar 2 | Mar 30–Apr 6 | 205 | two-plantings: Plant Mar 30 and again by Aug 13; both mature before Oct 21. | Aug 13 |
| Pole Beans | — | Apr 6–Apr 20 | 198 | fits: 65 days to maturity, 198 available after Apr 6. | Aug 3 |
| Spaghetti Squash | Mar 16 | Apr 13–Apr 20 | 184 | fits: 90 days to maturity, 184 available after Apr 13. | Jul 2 |
| Sunflowers | — | Mar 30–Apr 13 | 205 | fits: 70 days to maturity, 205 available after Mar 30. | Jul 29 |
| Tomatillos | Feb 2 | Apr 6–Apr 13 | 184 | fits: 75 days to maturity, 184 available after Apr 6. | Jul 10 |
| Watermelon | Mar 16 | Apr 6–Apr 13 | 184 | fits: 80 days to maturity, 184 available after Apr 6. | Jul 5 |
| Yellow Squash | Mar 16 | Apr 13–Apr 20 | 191 | two-plantings: Plant Apr 13 and again by Aug 13; both mature before Oct 21. | Aug 13 |
| Zinnias | Mar 2 | Mar 30–Apr 13 | 205 | two-plantings: Plant Mar 30 and again by Aug 8; both mature before Oct 21. | Aug 8 |
Month by month in Duncan
| Month | What to do |
|---|---|
| January | Start indoors: Chives (Jan 5), Lavender (Jan 5), Onion (Jan 5), Rosemary (Jan 5), Celery (Jan 19), Collards (Jan 19), +5 more. |
| February | Start indoors: Broccoli (Feb 2), Brussel Sprouts (Feb 2), Cabbage (Feb 2), Lettuce (Feb 2), Sage (Feb 2), Swiss Chard (Feb 2), +8 more. Direct sow from: Arugula (Feb 2), Beets (Feb 2), Dill (Feb 2), Peas (Feb 2), Radish (Feb 2), Spinach (Feb 2), +1 more. Plant: Strawberry (Feb 23). |
| March | Start indoors: Bok Choy (Mar 2), Corn (Mar 2), Cosmos (Mar 2), Nasturtiums (Mar 2), Okra (Mar 2), Zinnias (Mar 2), +9 more. Direct sow from: Cilantro (Mar 2), Turnip (Mar 2), Carrots (Mar 9), Potatoes (Mar 16), Sunflowers (Mar 30). Transplant from: Broccoli (Mar 2), Brussel Sprouts (Mar 2), Cabbage (Mar 2), Collards (Mar 2), Kale (Mar 2), Lettuce (Mar 2), +12 more. Last frost around March 30. |
| April | Direct sow from: Beans (Apr 6), Pole Beans (Apr 6). Transplant from: Celery (Apr 6), Chives (Apr 6), Corn (Apr 6), Okra (Apr 6), Oregano (Apr 6), Parsley (Apr 6), +17 more. |
| May | Succession plant lettuce and greens. Keep beds weeded and watered consistently. |
| June | Last sowing dates: Butternut Squash (Jun 22), Pumpkin (Jun 22), Cantaloupe (Jun 30), Celery (Jun 30), Melons (Jun 30). |
| July | Last sowing dates: Spaghetti Squash (Jul 2), Tomato (Jul 5), Watermelon (Jul 5), Pepper (Jul 10), Tomatillos (Jul 10), Eggplant (Jul 15), +2 more. |
| August | Last sowing dates: Brussel Sprouts (Aug 3), Pole Beans (Aug 3), Basil (Aug 8), Cosmos (Aug 8), Cucumber (Aug 8), Zinnias (Aug 8), +10 more. |
| September | Last sowing dates: Cabbage (Sep 2), Carrots (Sep 2), Beets (Sep 3), Dill (Sep 3), Swiss Chard (Sep 3), Calendula (Sep 8), +8 more. |
| October | Last sowing dates: Arugula (Oct 2), Spinach (Oct 2), Radish (Oct 3). |
| November | Direct sow from: Garlic (Nov 4). First frost around November 4. Last sowing dates: Garlic (Nov 25). |
| December | Harvest remaining cold-hardy crops: kale, carrots, and beets. Plant garlic bulbs for next year. |
Frequently Asked Questions
What is the last frost date for Duncan, OK (ZIP 73533)?
The median last spring frost date for Duncan, OK (ZIP code 73533) is around March 30. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area. One year in ten frost ends before March 17; one in ten it runs past April 13.
What is the first fall frost date in Duncan, OK?
The median first fall frost date for Duncan, OK is around November 4. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses. The first frost arrives around October 18 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Duncan, OK?
The frost-free growing season in Duncan is about 219 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side. In Duncan (219 frost-free days, a long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
What USDA hardiness zone is Duncan, OK?
Duncan, OK is in USDA hardiness zone 8a (2023 USDA Plant Hardiness Zone Map). Zones come from the average coldest winter temperature, so they tell you which perennials survive the winter; the frost dates on this page tell you when to plant.
When should I start tomatoes indoors in Duncan, OK?
Start tomatoes indoors Feb 23 and plant out Apr 13 in Duncan. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Duncan?
Two: plant Mar 2 and again by Sep 13; both mature before Nov 11.
When do I plant garlic in Duncan?
Nov 4 to Nov 25; it overwinters and is ready the following summer.
Can I get two tomato crops in Duncan?
Yes: plant out Apr 13 for a summer crop, and set out a second round of transplants by Jul 5 for a fall crop.
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