Growing Didiscus (Blue Lace Flower): A Complete Profile
By Growing Home Greens Team · August 10, 2026
Didiscus, also called blue lace flower, is a sweet-scented cut flower that pairs stiff, sturdy stems with a delicate, lacy flower head, an unusual combination that makes it a favorite for bouquets.
Direct-seed for the best roots
Direct-seeding is recommended, done after the last frost, with the seed covered rather than left exposed since darkness aids germination. Transplanting is possible, started 4 to 6 weeks before the last frost, but the plant dislikes root disturbance, and direct-sown plants noticeably outperform transplanted ones. Germination takes 14 to 21 days at 70-72°F. Sow a new round every 2 to 3 weeks from spring through summer for continuous blooms. Space plants 6 to 12 inches apart.
Harvest
Cut once about half the flowers on the umbel have opened. Vase life runs 8 to 10 days, among the longer-lasting cut flowers here.
Didiscus has no well-established companion pairings, and nothing it needs to be kept away from. At 2 plants per square foot, it’s a good direct-sown addition to a cutting bed in the Garden Designer, planned in succession for continuous cuts through the season.
Source: Didiscus: Key Growing Information, Johnny’s Selected Seeds.
Companion planting guide for Didiscus (Blue Lace Flower) · Find your planting dates
Typically viable in USDA zones 2-11. Not sure your zone? Look it up by ZIP code.
Mature height: 2-3 ft
Method: Direct sow: Direct-sow outside. It doesn't transplant well, or doesn't need the extra time indoors.
When to plant didiscus (blue lace flower), by zone
Every zone didiscus (blue lace flower) grows in. Pick your zone in the header and it will be highlighted here. Each zone links to its full page.
| Zone | Start indoors | Sow or plant out | Bloom |
|---|---|---|---|
| 2a & 2b | Not usually | May 20–May 27 | Aug 18–Aug 25 |
| 3a & 3b | Not usually | May 30–Jun 6 | Aug 28–Sep 4 |
| 4a & 4b | Not usually | May 15–May 22 | Aug 13–Aug 20 |
| 5a & 5b | Not usually | May 10–May 17 | Aug 8–Aug 15 |
| 6a & 6b | Not usually | Apr 25–May 2 | Jul 24–Jul 31 |
| 7a & 7b | Not usually | Apr 10–Apr 17 | Jul 9–Jul 16 |
| 8a & 8b | Not usually | Mar 25–Apr 1 | Jun 23–Jun 30 |
| 9a & 9b | Not usually | Feb 15–Feb 22 | May 16–May 23 |
| 10a & 10b | Not usually | Jan 30–Feb 6 | Apr 30–May 7 |
| 11a & 11b | Not usually | Jan 1–Jan 8 | Apr 1–Apr 8 |
Bloom dates are about 90 days after the sow or plant-out date.
Zone 2 sows before zone 3 here, which looks wrong and is not. USDA zones rank winter cold, not season length, and zone 2 is mostly interior Alaska, where hard winters come with warm summers. More on what a zone measures.
See exact start-indoors, direct-sow, and harvest dates for your zone →
How many Didiscus (Blue Lace Flower) plants fit per square foot?
Spacing: 2 per square foot (square-foot-gardening spacing). Mature height: 2-3 ft.
Varieties worth considering
- 'Lacy Lavender Blue' didiscus: Johnny's Selected Seeds recommends this as a sweet-scented cut flower with stiff stems and delicate appearance, one of their standard didiscus color offerings. (source)
- 'Lacy White' didiscus (best for: white color): Johnny's Selected Seeds lists this as sharing the same sweet-scented, stiff-stemmed, delicate character as Lacy Lavender Blue, in white. (source)
- 'Lacy Pink' didiscus (best for: pink color): Johnny's Selected Seeds lists this as the pink color option in the same Lacy series, also sold as an organic seed. (source)
Why each variety is listed comes from the source shown next to it. We haven't grown these ourselves yet, so treat this as a research-backed starting point, not a personal endorsement. The buy links are separate from those sources: they go to seed suppliers that sell that exact variety, and we may earn a commission on some of them.
Where to buy didiscus seeds
None of the seed suppliers we list carries didiscus seeds right now. A local garden center or a specialty seed house is the place to look.
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See it growing
Search YouTube for "growing didiscus (blue lace flower)" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
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Growing Didiscus (Blue Lace Flower): A sweet-scented cut flower with stiff stems and a delicate, lacy look, whose roots dislike disturbance.
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