Wax Begonia in Zone 5a & 5b
Begonia semperflorens
Yes, wax begonia grows in zones 5a and 5b. Start seeds indoors Feb 15–Feb 22 and plant out May 24–May 31.
When to plant wax begonia in zone 5b
Zones 5a and 5b 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 | Feb 15–Feb 22 |
|---|---|
| Direct sow / transplant outside | May 24–May 31 |
| Estimated bloom | Aug 22–Aug 29 (~90 days after transplanting) |
Spacing: 2 per square foot (square-foot-gardening spacing). Mature height: 0.5-2 ft.
Plant alongside it in zone 5b
These go outside within two weeks of wax begonia in zone 5b, so one planting day can cover them.
- NasturtiumMay 17–May 24
- MarigoldMay 17–May 24
- Angelonia (Summer Snapdragon)May 24–May 31
- Bee BalmMay 24–May 31
- Black-Eyed Susan VineMay 24–May 31
- Chrysanthemum (Garden Mum)May 24–May 31

Wax begonia is the low, glossy-leaved bedding plant that flowers steadily from summer into autumn in shade.
How wax begonia fits zone 5's season
Zone 5b's frost-free window runs about 148 days, from May 10 to October 5. Wax begonia needs about 90 days from transplant to first bloom.
Wax Begonia planting windows in every zone
Zone 5b is highlighted. Useful for comparing against a neighbouring zone, or for a garden somewhere else.
| Zone | Start indoors | Sow or plant out | Bloom |
|---|---|---|---|
| 3a & 3b | Mar 7–Mar 14 | Jun 13–Jun 20 | Sep 11–Sep 18 |
| 4a & 4b | Feb 20–Feb 27 | May 29–Jun 5 | Aug 27–Sep 3 |
| 5a & 5b (your zone) | Feb 15–Feb 22 | May 24–May 31 | Aug 22–Aug 29 |
| 6a & 6b | Jan 31–Feb 7 | May 9–May 16 | Aug 7–Aug 14 |
| 7a & 7b | Jan 16–Jan 23 | Apr 24–May 1 | Jul 23–Jul 30 |
| 8a & 8b | Dec 31–Jan 7 | Apr 8–Apr 15 | Jul 7–Jul 14 |
| 9a & 9b | Nov 23–Nov 30 | Mar 1–Mar 8 | May 30–Jun 6 |
| 10a & 10b | Nov 7–Nov 14 | Feb 13–Feb 20 | May 14–May 21 |
| 11a & 11b | Oct 9–Oct 16 | Jan 15–Jan 22 | Apr 15–Apr 22 |
Bloom dates are about 90 days after the sow or plant-out date, not after starting seeds indoors.
Good companions
No well-established companions for wax begonia.
Where to buy wax begonia seeds
None of the seed suppliers we list carries wax begonia seeds right now. A local garden center or a specialty seed house is the place to look.
See why we recommend these suppliers →
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 wax begonia" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 5b calendar · Plan your beds in the Garden Designer →

Pin this for later
Growing Wax Begonia in USDA zone 5b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
Save to Pinterest