Seed Distance Chart
Vegetable | Cycle | Pollination | Pollinator | Isolation Distance | Seed | Saving Ease | Direct | Notes |
| Bean | A | Self | 100’ | 2-3 yrs | easy | D | Lose vigor rapidly. | |
| Soybean | A | Self | 100’ | 2-3 yrs | easy | D | ||
| Beet/Chard | B | Cross | Wind | ½ mi | 3-5 yrs | * | D | Beets cross with chards. |
Broccoli/Kale/ Cauliflower | B | Cross | Insects | ½ mi | 3-5 yrs |
T | Crossing among brassica species is complex. Consult a good reference book. | |
| Carrot | B | Cross | Insects | 1500’ | 2-3 yr | * | D | Crosses with wild species, like Queen Anne’s Lace. |
| Celery | B | Cross | Insects | 1500’ | 2-3 yrs | * | T | |
| Corn | A | Cross | Wind | ½ mi | 2-3 yrs | D | Adequate pollination essential. | |
| Cucumber | A | Cross | Insects | 1500’ | 5-10 yrs | D/T | Harvest at yellow blimp stage. | |
| Eggplant | A | Self | 150’ | 2-3 yrs | easy* | T | ||
| Leek | B | Cross | Insects | 1500’ | 2 yrs | * | D | |
| Onions | B | Cross | Insects | 1500’ | 1 yr | * | D | Sets produce green onions. |
| Lettuce | A | Self | 50’ | 2-3 yrs | easy | D/T | ||
| Melon | A | Cross | Insects | ½ mi | 3-5 yrs | D/T | Muskmelons will not cross with watermelons. | |
| Mustard | A | Cross | Insects | ½ mi | 3-5 yrs | D/T | Crosses with wild species. | |
| Pea | A | Self | 50; | 2-3 yrs | easy | D | Do not save from diseased plants. | |
| Pepper | A | Both | Insects | 500’ | 2-3 yrs | T | Some varieties cross more readily than others. | |
| Radish | A | Cross | Insects | 1500’ | 3-5 yrs | D | ||
| Spinach | A | Cross | Wind | ½ mi | 2-3 yrs | * | ||
Squash/ Pumpkin | A | Cross | Insects | 1500’ | 2-5 yrs |
D/T | Moschata 2-3 yrs, pepo & maxima 3-5 yrs. These three species generally do not cross. | |
| Tomato | A | Self | 25-100’ | 5-10 yrs | easy | T | Potato-leaf types need the greater isolation distance. |
Cycle: A = annual, B = biennial
Pollination: Self = self-pollinated, Cross = cross-pollinated by another plant.
Isolation Distance: recommended distance by which different varieties must be separated to prevent unwanted cross-pollination.
Seed Longevity: Averages, not guarantees. Seed longevity depends on the condition under which the crop was grown and how the seeds have been stored.
Direct/Transplant: how to plant; direct seed or start seed before planting out.
*Easy Seeds to Save
All vegetables that are self-pollinated are easy to save. Vegetables that are marked with an asterisk (*) are also easy, but since they cross, you’ll have to learn a little to make sure that you get plants like the ones you started with.
4/2026