Garden chart
Seed Sowing Depth Chart by Vegetable and Flower
The general rule is to sow a seed at a depth of roughly two to three times its diameter — bury it deeper and it may run out of stored energy before reaching sunlight; sow it too shallow and it dries out before it germinates. Fine seeds like lettuce and petunia actually need light to germinate and should barely be covered.
| Seed | Sowing depth | Typical germination time | Soil temp for germination |
|---|---|---|---|
| Bean (bush/pole) | 1–1.5 in | 6–10 days | 60–85°F |
| Pea | 1–1.5 in | 7–14 days | 40–75°F |
| Corn | 1–2 in | 6–10 days | 60–95°F |
| Squash/pumpkin | 1 in | 6–10 days | 65–95°F |
| Cucumber | 0.5–1 in | 5–10 days | 60–95°F |
| Carrot | 0.25 in | 14–21 days | 45–85°F |
| Beet | 0.5–1 in | 7–14 days | 50–85°F |
| Radish | 0.5 in | 4–7 days | 45–85°F |
| Lettuce | surface, barely covered | 4–10 days | 40–75°F (needs light) |
| Spinach | 0.5 in | 7–14 days | 45–75°F |
| Onion | 0.25–0.5 in | 7–14 days | 50–95°F |
| Sunflower | 1 in | 7–14 days | 60–85°F |
| Zinnia | 0.25 in | 5–10 days | 65–75°F |
| Marigold | 0.25 in | 5–10 days | 70–75°F |
| Nasturtium | 0.5 in | 7–14 days | 65–70°F |
| Petunia | surface, not covered | 7–14 days | 70–75°F (needs light) |
Notes
- A soil thermometer is more useful than a calendar date for deciding when to sow — cold, wet soil rots seed before it germinates regardless of the date on the packet.
- In heavy clay, sow slightly shallower than the chart and cover with light compost or vermiculite instead of native soil to prevent crusting.
Put this into practice
- What to Plant This MonthWhat can I plant right now where I live?
- Frost Date LookupWhen is my last frost and how long is my season?
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