Flower Sprouts in Zone 6a & 6b
Brassica oleracea
Yes, Flower Sprouts grow in zones 6a and 6b. Start seeds indoors Mar 14–Mar 21 and plant out Apr 11–Apr 18.
When to plant Flower Sprouts in zone 6b
Zones 6a and 6b share the same average frost dates, so this page covers both.
Method: Start indoors: Start indoors from seed, then transplant outside. It needs a head start most zones can't give it by direct-sowing alone.
| Start indoors | Mar 14–Mar 21 |
|---|---|
| Direct sow / transplant outside | Apr 11–Apr 18 |
| Estimated harvest | Jul 20–Jul 27 (~100 days after transplanting) |
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 2-3 ft.
Plant alongside it in zone 6b
These go outside within two weeks of Flower Sprouts in zone 6b, so one planting day can cover them.
- OnionApr 4–Apr 11
- CarrotApr 4–Apr 11
- CabbageApr 11–Apr 18
- LettuceApr 11–Apr 18
- BroccoliApr 11–Apr 18
- Gai Lan (Chinese Broccoli)Apr 11–Apr 18
Flower Sprouts is a separately trademarked kale x Brussels sprouts cross from a different breeding line than Kalettes, though the two are similar in concept: small, ruffled, purple-and-green florets running up a tall stalk instead of the tight round sprouts of a standard Brussels plant.
How Flower Sprouts fit zone 6's season
Zone 6b's frost-free window runs about 173 days, from April 25 to October 15. Flower Sprouts need about 100 days from transplant to first harvest.
Flower Sprouts planting windows in every zone
Zone 6b is highlighted. Useful for comparing against a neighbouring zone, or for a garden somewhere else.
| Zone | Start indoors | Sow or plant out | Harvest |
|---|---|---|---|
| 2a & 2b | Apr 8–Apr 15 | May 6–May 13 | Aug 14–Aug 21 |
| 3a & 3b | Apr 18–Apr 25 | May 16–May 23 | Aug 24–Aug 31 |
| 4a & 4b | Apr 3–Apr 10 | May 1–May 8 | Aug 9–Aug 16 |
| 5a & 5b | Mar 29–Apr 5 | Apr 26–May 3 | Aug 4–Aug 11 |
| 6a & 6b (your zone) | Mar 14–Mar 21 | Apr 11–Apr 18 | Jul 20–Jul 27 |
| 7a & 7b | Feb 27–Mar 6 | Mar 27–Apr 3 | Jul 5–Jul 12 |
| 8a & 8b | Feb 11–Feb 18 | Mar 11–Mar 18 | Jun 19–Jun 26 |
| 9a & 9b | Jan 4–Jan 11 | Feb 1–Feb 8 | May 12–May 19 |
| 10a & 10b | Dec 19–Dec 26 | Jan 16–Jan 23 | Apr 26–May 3 |
| 11a & 11b | Nov 20–Nov 27 | Dec 18–Dec 25 | Mar 28–Apr 4 |
Harvest dates are about 100 days after the sow or plant-out date, not after starting seeds indoors.
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.
Good companions
- Radish: Radish (including the daikon form) is a documented trap crop for flea beetles, which prefer its mustard oils over other brassicas and can be sacrificed or pulled once infested: the same research cited on the radish page.
Where to buy Flower sprout seeds
None of the seed suppliers we list carries Flower sprout seeds right now. A local garden center or a specialty seed house is the place to look.
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing Flower Sprouts" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 6b calendar · Plan your beds in the Garden Designer →

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Growing Flower Sprouts in USDA zone 6b: when to start seeds indoors, when to direct-sow, and when to expect a harvest.
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