Reference
Which Seeds to Direct-Sow vs Start Indoors
The short answer
The rule of thumb: direct-sow crops that don't transplant well or that you sow in large numbers, and start indoors the crops that transplant readily but need a head start on the season. Root crops — beets, carrots, parsnips, radishes, rutabagas, turnips — should be sown directly because a disturbed taproot comes up misshapen; beans and corn also go straight in the ground.
Start indoors the warm-season fruiting crops (tomatoes, peppers, eggplant) and long-season cool crops (cabbage, broccoli, cauliflower) — they establish better as transplants and buy weeks of growing time. Cucurbits like cucumbers, melons, pumpkins, and squash can go either way, but transplant them very young and handle the roots gently.
Best direct-sown
- Root crops — beets, carrots, parsnips, radishes, rutabagas, turnips (transplanting misshapes the root).
- Beans and corn — typically not transplanted successfully.
- Fast or heavily-sown crops like radishes and leaf lettuce, where the sheer number of seeds makes transplanting impractical.
Best started indoors
- Warm-season fruiting crops — tomatoes, peppers, eggplant.
- Long-season cool crops — cabbage, broccoli, cauliflower (and lettuce) that need to mature before summer heat.
- These establish better and gain weeks of growing time from an indoor head start.
Can go either way
Cucurbits — cucumbers, melons, pumpkins, squash — transplant well but resent root disturbance, so move them while very small, right after the first true leaves. Many spring transplants (cabbage, broccoli, cauliflower, onions, spinach, root crops) can instead be direct-seeded in summer for a fall harvest.
Sources
Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.
- Iowa State University Extension — Growing vegetables in containers / direct seeding guidance — Root crops and crops with taproots do poorly transplanted and are best direct-seeded.
- Penn State Extension — Starting Your Summer Vegetable Garden: Seeds or Transplants? — Which crops establish better as transplants vs direct seed; cucurbits transplant if handled young.
- University of Maryland Extension — Starting Vegetable Seeds Indoors — Tomatoes, peppers, eggplant, cabbage family and lettuce benefit from indoor starting; beans, carrots, beets sown directly.