key growing information

How to Grow Clarkia From Seed

How to grow clarkia (godetia) from seed for cut flowers: starting transplants or sowing direct, cool growing temperatures, support, and the right stage to cut.

By Hensley’s Seed Co. September 3, 2026

Clarkia - Key Growing Information

'Salmon,' an exquisite pink variety of Clarkia, a wildflower native to the Western U.S.

DAYS TO GERMINATION:

Expect seedlings in 5–10 days at 65–70°F (18–21°C).

SOWING:

Transplants are recommended: start seed 4 weeks before planting out and cover with just 1/16" of soil, then harden off and set out after the last frost. To sow outdoors, plant as soon as the ground can be worked, pressing seed in and covering with 1/16" of soil; keep the surface moist until seedlings emerge and thin to 6–12" once they have true leaves. Clarkia likes it cool after germination: grow seedlings at 60–65°F (16–18°C) by day and 50°F (10°C) at night, and keep them below 75°F (24°C). Heat while plants are developing leads to weak, leggy stems.

LIGHT PREFERENCE:

Full sun, with some tolerance for part shade.

PLANT HEIGHT:

Depends on variety.

PLANT SPACING:

Space plants 6–12" apart.

HARDINESS ZONES:

Grown as an annual.

STEM LENGTH:

12-34".

VASE LIFE:

About 7–10 days.

HARVEST:

Clarkia unguiculata: Cut stems when the lowest flowers are just starting to open. Older blooms fall within about 5 days, while the buds above keep opening in the vase. Clarkia amoena: As the first flower on the stem opens.

SOIL REQUIREMENTS:

Ordinary soil with good drainage.

USES:

Cut flowers, pollinator plantings and borders.TIPS: A horizontal net or other support can help. SCIENTIFIC NAMES: Clarkia amoena, Clarkia unguiculataALTERNATE NAMES: Clarkia unguiculata: Elegant clarkia, mountain garland. Clarkia amoena: Satin flower, godetia, farewell-to-spring.