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.
When you plan to move plants outdoors.
wks
Default for Petunia: 6 weeks. Override if you like.

Your sowing timeline

  1. Start seeds indoors
    June 28, 2026

    Sow in trays about 6 weeks before transplanting.

  2. Transplant outdoors
    August 9, 2026

    transplant after danger of frost

  3. Direct sow (alternative)

    Petunia is not usually direct sown; start with transplants for best results.