Sow Phacelia after frost or as soon as the soil can be worked, press or barely cover the seed, and keep the surface moist until it sprouts.
Sow after frost, barely covered
| Factor | Recommended | Avoid |
|---|---|---|
| When | After last frost, or as soon as the soil can be worked in cool weather | Sowing into a frozen puddle |
| Depth | Press in or cover about 1/8 inch. A light covering is enough | Burying seed deep |
| Rate | About 6 seeds per foot in a row, or a broadcast cover stand | A clump that germinates then smothers itself |
| Moisture | Keep the surface moist until seedlings show, often 7 to 14 days | Letting the top crust dry out after sowing |
| Stubborn lots | Nick or scratch the coat, then soak overnight | Assuming every dry packet germinates overnight |
Direct sow is the usual method. Cool soil helps. [1] Scatter, then rake lightly so the seed is barely covered. [2] Some lots also germinate on the surface after frost if you press for contact. [3] Scratching the coat and an overnight soak can even out a stubborn packet. [4]
Is phacelia easy to grow from seed?
Yes, if you sow shallow, keep the surface moist, and do not bury the seed.
How to sow Phacelia
- Wait until after frost, or until you can work cool soil. Weed and rake a fine surface.
- Optional: nick or scratch the seed, then soak overnight and sow the same day.
- Scatter thinly, or sow about 6 seeds per foot in a row. For a cover stand, broadcast at the packet rate.
- Press the seed in, or cover about 1/8 inch. Do not bury it deep.
- Keep the surface moist until seedlings appear, often 7 to 14 days in cool weather. Then ease off.
- Thin to about 10 to 12 inches if you want airy plants. Leave a dense stand if this is cover.
- For a longer bloom, sow again two weeks later, once or twice.
How do I plant phacelia seed?
Sow after frost, barely covered, and keep the surface moist until it sprouts. Scarify and soak overnight if a lot is slow.
What fails at sowing
Deep burial stalls germination. A dry crust after sowing kills a shallow lot. Shade thins the stand later, but the sow itself fails first from depth and drought at the surface. Do not prick out a taprooted annual unless you must; sow where the plants will flower.
Will phacelia self-seed?
Lacy phacelia often does. Cut or till after bloom if you do not want volunteers.
Sow shallow after frost, keep the surface moist until it sprouts, and thin or leave a cover stand on purpose.
Related guides
Recommended plants
References
- [1] Johnny's Selected Seeds -
https://www.johnnyseeds.com/growers-library/flowers/phacelia/phacelia-key-growing-information.html - [2] Outsidepride -
https://www.outsidepride.com/resources/planting/phacelia-planting/ - [3] NC State Extension -
https://plants.ces.ncsu.edu/plants/phacelia-tanacetifolia/ - [4] Lady Bird Johnson Wildflower Center -
https://www.wildflower.org/plants/result.php?id_plant=phta
This note is part of Phacelia Guides.
More notes on making another plant live in Propagating Guides.
Updated: Reviewed by Bosquelle Editors