Sow Signal
2026 Swedona, IL Planting Calendar
Spring / Last Frost-based Planting
| Crop | # Weeks to Start Before Last Frost |
Start Inside (mm-dd) |
Direct Sow (mm-dd) |
Transplant (mm-dd) |
Notes |
|---|---|---|---|---|---|
| Acorn Squash | 05-06 | Sow after last frost in warm soil; give vines room to sprawl. | |||
| Arugula | 9 | 02-11 | 04-08 | Start indoors early with bright light; transplant to cool-season beds. Arugula is a cool-season green; direct sow about 1 week before last frost in workable soil. | |
| Asparagus | Plant asparagus crowns in a permanent trench as soon as soil can be worked. | ||||
| Banana Peppers | 9 | 02-11 | 05-06 | Start banana peppers 8–10 weeks before last frost for best yields. Transplant after frost when soil and nights are warm. Peppers stall in cool soil. | |
| Basil | 7 | 02-25 | 04-29 | Start Basil Seeds indoors Transplant after frost risk has passed. Basil blackens in cold conditions. | |
| Bay Laurel | 05-13 | Set out later once nights are reliably warm; bay laurel is cold-sensitive. | |||
| Bell Peppers | 9 | 02-11 | 05-06 | Peppers take a long time to germinate; start early in a warm spot. Transplant once nights are consistently above 55°F. Peppers stall in cool soil and recover slowly. | |
| Blackberries | 03-18 | Plant dormant blackberry canes in early spring; provide trellis/support as needed. | |||
| Blueberries | 03-18 | Plant dormant blueberry bushes in early spring while soil is workable; mulch and water in. | |||
| Bok Choy | 6 | 03-04 | 04-01 | Start bok choy indoors 4–6 weeks before last frost for spring planting. Direct sow bok choy at the beginning of spring once soil can be worked. | |
| Borage | 04-01 | Borage tolerates cool weather; sow before last frost for early flowers and pollinator support. | |||
| Broccoli | 7 | 02-25 | 04-15 | Start indoors to ensure plants are established before the heat hits. Broccoli can handle a light frost after being hardened off. | |
| Bush Beans | 04-22 | Sow after last frost when nights are mild. Cold soil can rot seed. | |||
| Butterhead Lettuce | 8 | 02-18 | 03-18 | 03-25 | Start butterhead indoors ~8 weeks before last frost for early heads. Direct sow butterhead in cool soil; thin for airflow. Transplant butterhead ~3 weeks before last frost; keep growth steady to reduce bolting. |
| Butternut Squash | 05-06 | Sow after last frost in warm soil; butternut needs a long season. | |||
| Cabbage | 7 | 02-25 | 03-25 | Start cabbage seeds indoors early to ensure they mature before summer heat. Cabbage is frost-hardy; move starts outside a few weeks before the final frost. | |
| Calendula | 04-01 | Calendula tolerates cool weather; sow a couple weeks before last frost. | |||
| Cantaloupe | 4 | 03-18 | 04-29 | 04-29 | Start in peat pots to avoid root disturbance during transplant. Direct sow after last frost once soil is warm. Thin to the strongest plants and keep moisture steady early on. Transplant only after frost risk is completely gone. Melons stall in cool soil. |
| Carrots | 03-25 | Carrots can handle a light frost. Sow directly in the soil. | |||
| Cauliflower | 6 | 03-04 | 04-01 | Start cauliflower 4–6 weeks before transplanting (indoor start). Transplant cauliflower about 2 weeks before last frost; protect from cold snaps. | |
| Chives | 04-01 | Plant chives in early spring; cold-hardy perennial (or sow as soon as workable). | |||
| Cilantro | 04-01 | Cilantro loves cool weather; sow before the heat hits. | |||
| Collard Greens | 03-18 | Hardy greens that can handle a bit of frost. | |||
| Cosmos | 04-22 | Sow around last frost once weather settles | |||
| Cowpeas (Southern Peas) | 05-13 | Sow in late spring/early summer once soil is hot; cowpeas are heat-loving. | |||
| Cucumbers | 04-29 | Sow in warm soil. Trellis to save space and improve airflow. | |||
| Daikon Radish | 04-01 | Daikon can be spring-sown early, but performs best as a fall crop. | |||
| Dill | 04-01 | Sow early; dill thrives in cool spring weather. | |||
| Eggplant | 8 | 02-18 | 05-06 | Sow once soil has warmed; cold soil causes poor germination and uneven stands. Transplant after frost risk has passed. Confirm soil warmth with a 2–4 inch morning soil thermometer reading for best establishment. | |
| Endive | 7 | 02-25 | 03-25 | 04-01 | Start endive indoors for reliable spring stands; keep seedlings cool and steady. Direct sow endive in cool soil; thin to reduce bitterness from stress. Transplant endive into cool beds; steady watering helps quality. |
| Escarole | 7 | 02-25 | 03-25 | 04-01 | Start escarole indoors; steady growth improves quality. Direct sow escarole in cool weather; thin for airflow. Transplant escarole into cool beds; keep evenly watered. |
| Fava Beans | 03-04 | Fava beans tolerate cold; sow very early spring for pods before heat. | |||
| Fennel | 04-22 | Direct sow fennel after frost risk; steady growth prevents bolting. | |||
| Grapes | 03-18 | Plant grapes early spring while dormant; choose a sunny, well-drained site. | |||
| Green Beans | 04-22 | Sow once soil is warm. Beans rot in cold, wet soil. | |||
| Ground Cherries | 7 | 02-25 | 04-29 | Start ground cherries 6–8 weeks before last frost; they behave like tomatoes. Transplant ground cherries after last frost; cage or mulch for cleaner fruit. | |
| Honeydew | 4 | 03-18 | 04-29 | 04-29 | Start honeydew in pots 3–4 weeks before transplanting to avoid root disturbance. Direct sow once soil is warm after last frost. Transplant once soil is warm after last frost. |
| Hot Peppers (General) | 9 | 02-11 | 05-06 | Hot peppers are slow; start 8–10 weeks before last frost with steady warmth. Transplant after frost once nights stay warm (55°F+). Peppers stall in cool soil. | |
| Iceberg Lettuce | 8 | 02-18 | 03-18 | 03-25 | Start iceberg indoors ~8 weeks before last frost for head lettuce. Direct sow iceberg early; consistent moisture improves head formation. Transplant iceberg ~3 weeks before last frost; row cover helps in cold snaps. |
| Jalapeño Peppers | 9 | 02-11 | 05-06 | Start Jalapeños early; they need consistent warmth to germinate. Transplant after frost once nights stay above 55°F. Peppers stall in cool soil. | |
| Jerusalem Artichoke (Sunchoke) | 03-18 | Plant sunchoke tubers in early spring while soil is workable; choose a permanent spot. | |||
| Kale | 03-18 | Kale is incredibly frost-tolerant; sow early. | |||
| Kohlrabi | 8 | 02-18 | 03-18 | Start kohlrabi indoors 4–6 weeks before transplanting. Transplant kohlrabi ~4 weeks before last frost; cold-hardy when hardened off. | |
| Lavender | 10 | 02-04 | 04-29 | Lavender from seed is slow; start early with bright light and well-drained medium. Transplant lavender after frost risk; avoid soggy soils. | |
| Leeks | 10 | 02-04 | 03-18 | Start leeks indoors ~8–10 weeks before last frost for strong transplants. Transplant leeks ~4 weeks before last frost; cold-tolerant once hardened. | |
| Lemongrass | 8 | 02-18 | 05-13 | Start lemongrass indoors; it needs a long warm season and strong light. Transplant after frost once soil is very warm; lemongrass is cold-sensitive. | |
| Lettuce | 8 | 02-18 | 03-18 | Start indoors for reliable early plants; keep seedlings cool and evenly moist. Lettuce seeds germinate best in cool soil. | |
| Lima Beans | 04-29 | Sow once soil is thoroughly warm; limas need more heat than snap beans. | |||
| Marigolds | 6 | 03-04 | 04-22 | 04-15 | Start marigolds indoors for earlier blooms. Direct sow marigolds for easy blooms. Transplant marigolds around last frost once hardened off. |
| Marjoram |