My Everchanging Garden

Gardening That Grows With Me

Perennial Seed Starting Schedule

This is my first year starting perennials from seed. I’m curating seed starting times and germination information as best I can from the different seed suppliers.

All perennial seedlings do not need a lot of fertilizer, wait until 3 to 4 weeks old to fertilize and then only half strength. Transplant into 3 or 4-inch pots after at least 2 sets of true leaves for good root growth.


  • start in March / April for summer blooms
  • seed depth 1/8″ or 3mm
  • will flower 12 to 14 weeks after seeding.
  • soil temperature 65-70°F / 18-21°C
  • germinates in 10 to 15 days

Balloon Flower

  • start in January / February
  • sow in cell packs or 2-inch pots
  • surface sow, seeds need light to germinate
  • seedlings are fragile, handle with care
  • temperature 65-70°F / 18-21°C
  • germinates in 21 to 30 days
  • can be winter sowed, will germinate once temperatures reach 21°C or 70°F


  • start late winter for summer flowers (January / February)
  • seed depth 1/4 inch / 6mm (press into soil and cover lightly)
  • start in the intended pot; seedlings do not like to be transplanted
  • soil temperature 70-75°F / 21-24°
  • germinates in 8 to 21 days
  • light: For green growth, provide 18-24 hours of artificial light daily. For flowers, provide 9 hours per day for the first two weeks after germination, then 14 hours thereafter.
  • move outdoors when the day length reaches 13+ hours (mid-April)


  • start 6 to 8 weeks before the last frost date (late March)
  • no stratification required
  • do not or barely cover, may need some light to germinate
  • temperature 60-70°F / 16-21°C
  • germinates in 14 to 28 days
  • transplant into individual containers when seedlings have their first true set of leaves
  • may not flower until the second year so transplant into holding garden


  • start 10 to 12 weeks before the last frost date (end February)
  • Ball Seed: plug time 5 to 6 weeks, transplant to finish 8 to 11 weeks – so a total of 17 weeks for growers to sell flowering plants
  • press into soil, do not cover
  • keep at 75°F for germination in 21 to 30 days
  • seedlings can be grown cooler at 68-72°F or 20-22°F
  • flowering: the warmer the growing temperature, the sooner it will flower.

Echinacea and perennial salvia are long-day flowers. They need at least 14 hours of light to bloom. Consider adding supplemental light. Bulk up the plant during short day (no extra light), then add light to speed flowering.

Leave a Reply

Your email address will not be published. Required fields are marked *

14 − 8 =