Growing Impatiens: A Complete Profile
By Growing Home Greens Team · August 20, 2026
Impatiens flowers reliably in shade, which almost nothing else here does. It also carries a disease problem worth understanding before you plant a whole bed of it.
Downy mildew has no fix
NC State Extension notes that Impatiens walleriana is susceptible to downy mildew caused by Plasmopara obducens, and states plainly that fungicides used for other fungal diseases will not work on it. The disease collapsed impatiens plantings across the country and the spores persist in soil.
If a planting collapses, replanting the same species in the same place is likely to fail again. The toolbox points to Impatiens hawkeri, New Guinea impatiens, as the resistant alternative.
Deep shade is fine
Part shade to full shade, with enough moisture. It runs 6 inches to 2 feet in both directions depending on cultivar. Perennial only in zones 10 and 11, so it is an annual for nearly everyone.
Slow from seed
Ten weeks indoors before the last frost, surface sown because the seed needs light. Most gardeners buy starts instead, and given the sowing timeline that is a reasonable choice rather than a lazy one.
Source: NC State Extension Gardener Plant Toolbox, Impatiens walleriana.
Companion planting guide for Impatiens · Find your planting dates
Typically viable in USDA zones 3-11. Not sure your zone? Look it up by ZIP code.
Mature height: 0.5-2 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 impatiens, by zone
Every zone impatiens 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 |
|---|---|---|---|
| 3a & 3b | Mar 21–Mar 28 | Jun 13–Jun 20 | Aug 27–Sep 3 |
| 4a & 4b | Mar 6–Mar 13 | May 29–Jun 5 | Aug 12–Aug 19 |
| 5a & 5b | Mar 1–Mar 8 | May 24–May 31 | Aug 7–Aug 14 |
| 6a & 6b | Feb 14–Feb 21 | May 9–May 16 | Jul 23–Jul 30 |
| 7a & 7b | Jan 30–Feb 6 | Apr 24–May 1 | Jul 8–Jul 15 |
| 8a & 8b | Jan 14–Jan 21 | Apr 8–Apr 15 | Jun 22–Jun 29 |
| 9a & 9b | Dec 7–Dec 14 | Mar 1–Mar 8 | May 15–May 22 |
| 10a & 10b | Nov 21–Nov 28 | Feb 13–Feb 20 | Apr 29–May 6 |
| 11a & 11b | Oct 23–Oct 30 | Jan 15–Jan 22 | Mar 31–Apr 7 |
Bloom dates are about 75 days after the sow or plant-out date, not after starting seeds indoors.
See exact start-indoors, direct-sow, and harvest dates for your zone →
How many Impatiens plants fit per square foot?
Spacing: 2 per square foot (square-foot-gardening spacing). Mature height: 0.5-2 ft.
Varieties worth considering
- Beacon series (best for: downy mildew resistance): Bred by PanAmerican Seed and described by Illinois Extension and NC State Extension as highly resistant to impatiens downy mildew, the disease that wiped bedding impatiens out of many gardens. Highly resistant isn't the same as immune. (source) Buy seeds: Burpee
- Imara XDR series (best for: downy mildew resistance): Syngenta's downy-mildew-resistant line, "XDR" for extra disease resistance. Illinois Extension reports that Syngenta had the claim checked by plant pathologists at Cornell, who confirmed it. A good alternative where Beacon isn't sold. (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 impatiens seeds
True Leaf Market · Burpee (each supplier's impatiens seeds)
The varieties we recommend above each have their own buy links, for the suppliers that sell that exact variety.
As an Amazon Associate we earn from qualifying purchases. Some links on this page also go to other retailers we may earn a commission from as an affiliate, at no extra cost to you. We only recommend products with a clear consensus of positive, independent reviews, or ones we bought and use ourselves. Each item on our gear page says which.
See it growing
Search YouTube for "growing impatiens" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
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Growing Impatiens: The standard answer for a shady square, and the plant a downy mildew epidemic nearly removed from gardens.
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