Cover crops

Pick a goal or the crop you are following, then open a note for timing and caveats. Pairs with What can I grow? and companion planting when you plan successions.

Goal

Any Nitrogen fixation Biomass / organic matter Weed suppression Quick turnover (≈6–8 wk)Winter / shoulder season Pollinator support Soil structure / deep roots

After this crop

Rough rotation memory for what the last planting tended to demand — not a soil test.

Any Tomato / pepper / eggplant Brassicas Squash / cucumber / melon Corn Beans / peas Lettuce / greens Carrot / roots Onion / garlic

Buckwheat
Buckwheat (Fagopyrum esculentum)
Classic summer gap filler: sow after an early harvest, let it bloom for pollinators if you can, then mow or till in before seeds mature unless you want volunteers.
Field peas + oats
Austrian winter field pea (Pisum sativum subsp. arvense) with oats (Avena sativa)
Beginner-friendly mix: oats winter-kill in cold zones while peas may overwinter lightly; tune seed ratio to your winter.
Winter rye
Cereal rye (Secale cereale)
Aggressive grower with allelopathic reputation — terminate early enough before corn or small seeds unless you plan a tilled stale seedbed.