Seed-Starting Calculator
Pick your season, zone, crop and block size — get your sow-in-blocks window and transplant window, plus a check that your timing actually fits your block. Built on the same soil-block timing method we use on our own farm: blocked seedlings establish about 25% faster than plug trays, and every block size has a practical ceiling before seedlings need to move on.
How this works: timings start from standard plug-tray growing guidelines, scaled ~25% faster for soil blocks (air-pruned roots establish quicker), with each block size capped at its practical ceiling — 0.9″ ≈ 3 weeks, 1.125″ ≈ 4 weeks, 1.5″–2.25″ ≈ 6 weeks. Fall overwinter timing follows the proven cool-season “hardy annual” approach (transplant 6–8 weeks before first frost). When in doubt, start later — an overgrown seedling costs more than a young one. More depth: When to start seeds.