PLANTOMETRY

Seed Starting Calculator

Know exactly when to start seeds

Pick a crop and your key date. Plantometry counts back from frost or your transplant date to tell you when to sow indoors, when to move plants out, and when direct sowing is an option.

Seed-starting timing is crop-specific, so a crop is required here.
The average last spring frost for your area. Look it up by ZIP if unsure.
wks
Default for Lisianthus (Eustoma grandiflorum): 12 weeks. Override if you like.

Your sowing timeline

  1. Start seeds indoors
    May 17, 2026

    Sow in trays about 12 weeks before your last frost.

  2. Transplant / plant out
    August 9, 2026

    Harden off, then transplant once frost risk has passed.

  3. Direct sow (alternative)

    Lisianthus (Eustoma grandiflorum) is not usually direct sown; start with transplants for best results.