Plant green bean seeds 1 to 2 inches apart and 1 inch deep, with 18 inches between rows. Nodules on the roots contain a Rhizobium bacteria that converts elemental nitrogen from the air into a form the plant can use. If you've never grown green beans in your garden before, treat the seeds before planting with Rhizobium bacteria, available from most nurseries or garden seed catalogs, he advised. To keep cole crop seeds cool and prevent the soil from crusting, cover the seeds with vermiculite. Keep the soil moist until seedlings emerge.
Flea beetles can be a major problem for young broccoli, cabbage, cauliflower and kohlrabi seedlings.
To help deter the beetles, cover each row or hill of seed with transparent, woven polyester row cover. The cover also slows water evaporation from the soil. Support the row cover with small, wire hoops and anchor it on both sides with soil. Remove the cover after seedlings form their first true leaves. Thin cole crop seedlings to one plant per grouping.