Growing Kalettes: A Complete Profile
By Growing Home Greens Team · August 10, 2026
Kalettes is a trademarked cross between kale and Brussels sprouts, grown for small, frilly-leaved florets that look nothing like the tight round sprouts of its Brussels parent, with a milder, sweeter flavor to match.
A heavier feeder than most brassicas
The best florets come from rich, fertile soil with a pH between 6.5 and 7.5. Fertilize at about 75 percent the nitrogen rate used for Brussels sprouts, and irrigate during dry weather to keep growth steady; skimping on fertility shows up directly in floret quality rather than just plant size.
Grown like Brussels sprouts
Culture otherwise follows Brussels sprouts closely: start seed indoors around 6 weeks before the last frost, a quarter to a half inch deep, and transplant out once the season allows. Expect a similar overall plant size and growing timeline, just with a more open, ruffled harvest at the end instead of tight buds along the stalk.
Kalettes has no well-established companion pairings, and nothing it needs to be kept away from. At 1 plant per square foot, it’s a good brassica-bed addition to the Garden Designer for gardeners who want something a little different from standard Brussels sprouts.
Source: Kalettes: Key Growing Information, Johnny’s Selected Seeds.
Companion planting guide for Kalettes · 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: Start indoors: Start indoors from seed, then transplant outside. It needs a head start most zones can't give it by direct-sowing alone.
When to plant Kalettes, by zone
Every zone Kalettes grow 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 | 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 | 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.
See exact start-indoors, direct-sow, and harvest dates for your zone →
How many Kalettes plants fit per square foot?
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 2-3 ft.
Good companions for Kalettes
- 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.
Full companion guide, including what to keep away from Kalettes →
Varieties worth considering
- 'Autumn Star' (F1) Kalettes: Johnny's Selected Seeds recommends this hybrid for an early-season harvest, their standard Kalettes offering. (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 kalette seeds
None of the seed suppliers we list carries kalette 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 Kalettes" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
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Growing Kalettes: A trademarked cross between kale and Brussels sprouts, grown for small, frilly-leaved florets rather than the tight round sprouts of its Brussels parent.
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