Siloam Springs, AR planting zone & frost dates
Siloam Springs is in USDA hardiness zone 7a. The last spring frost usually comes around March 31 and the first fall frost around November 2, for a growing season of about 216 days.
Planting calendar for Siloam Springs
Dates are counted from the average last spring frost (March 31) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Feb 3 – Feb 17 Transplant outdoors: Apr 7 – Apr 14 |
| Peppers | Start seeds indoors: Jan 20 – Feb 3 Transplant outdoors: Apr 14 – Apr 21 |
| Eggplant | Start seeds indoors: Jan 20 – Feb 3 Transplant outdoors: Apr 14 – Apr 21 |
| Broccoli | Start seeds indoors: Jan 20 – Feb 3 Transplant outdoors: Mar 3 – Mar 17 |
| Cabbage | Start seeds indoors: Jan 20 – Feb 3 Transplant outdoors: Mar 3 – Mar 17 |
| Onions (sets) | Plant outdoors: Mar 3 – Mar 17 |
| Peas | Sow outdoors: Feb 17 – Mar 3 |
| Spinach | Sow outdoors: Feb 17 – Mar 3 |
| Lettuce | Sow outdoors: Mar 3 – Mar 17 |
| Carrots | Sow outdoors: Mar 3 – Mar 17 |
| Potatoes | Plant outdoors: Mar 3 – Mar 17 |
| Beans | Sow outdoors: Apr 7 – Apr 14 |
| Sweet corn | Sow outdoors: Apr 7 – Apr 14 |
| Cucumbers | Sow outdoors: Apr 7 – Apr 14 |
| Squash & zucchini | Sow outdoors: Apr 7 – Apr 14 |
| Basil | Start seeds indoors: Feb 17 – Mar 3 Transplant outdoors: Apr 7 – Apr 14 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 7 (8 weeks before the average first fall frost on Nov 2).
Useful for zone 7a gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Mar 13 | Mar 31 | Apr 18 |
| First 32°F frost in fall is before | Nov 19 | Nov 2 | Oct 20 |
How to read it: in spring there is a 10% chance of a frost after April 18, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 20. A hard freeze (28°F) usually ends around March 19.
Hardiness zone by ZIP code in Siloam Springs
- 72761 zone 7a
Nearby cities
- Centerton zone 7a, last frost Apr 12
- Bentonville zone 7a, last frost Apr 12
- Bella Vista zone 7a, last frost Apr 5
- Fayetteville zone 7a, last frost Apr 4
- Springdale zone 7a, last frost Apr 4
- Rogers zone 7a, last frost Apr 12
- Van Buren zone 8a, last frost Mar 25
- Fort Smith zone 8a, last frost Mar 25
Questions
What growing zone is Siloam Springs, AR?
Siloam Springs is in USDA Plant Hardiness Zone 7a (average extreme winter low 0°F to 5°F), according to the USDA 2023 map.
When is the last frost in Siloam Springs?
The average last spring frost (32°F) in Siloam Springs is March 31. There is still a 10% chance of frost until April 18.
When can I plant tomatoes in Siloam Springs?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 7 – Apr 14. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Kansas 2 Ne, OK (USC00344672), 21.5 km (13.4 mi) from the city center, elevation 363 m, based on 18 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.