Vinca (Madagascar Periwinkle) in Zone 5a & 5b
Catharanthus roseus
Yes, vinca (Madagascar periwinkle) grows in zones 5a and 5b. Start seeds indoors Mar 1–Mar 8 and plant out May 24–May 31.
When to plant vinca (Madagascar periwinkle) 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 | Mar 1–Mar 8 |
|---|---|
| Direct sow / transplant outside | May 24–May 31 |
| Estimated bloom | Aug 12–Aug 19 (~80 days after transplanting) |
Spacing: 1 per square foot (square-foot-gardening spacing). Mature height: 1-1.5 ft.
Plant alongside it in zone 5b
These go outside within two weeks of vinca (Madagascar periwinkle) 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
Vinca (Madagascar periwinkle, botanically Catharanthus roseus) is built for heat that stops other flowers cold. Growing In The Garden describes it as synonymous with hot weather in the low desert, blooming through Phoenix summers with little fuss once it's established, a low, 12- to 18-inch mound of flat, five-petaled pink, white, or red flowers, often with a contrasting eye at the center.
How vinca (Madagascar periwinkle) fits zone 5's season
Zone 5b's frost-free window runs about 148 days, from May 10 to October 5. Vinca (Madagascar periwinkle) needs about 80 days from transplant to first bloom.
Vinca (Madagascar Periwinkle) 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 |
|---|---|---|---|
| 2a & 2b | Mar 11–Mar 18 | Jun 3–Jun 10 | Aug 22–Aug 29 |
| 3a & 3b | Mar 21–Mar 28 | Jun 13–Jun 20 | Sep 1–Sep 8 |
| 4a & 4b | Mar 6–Mar 13 | May 29–Jun 5 | Aug 17–Aug 24 |
| 5a & 5b (your zone) | Mar 1–Mar 8 | May 24–May 31 | Aug 12–Aug 19 |
| 6a & 6b | Feb 14–Feb 21 | May 9–May 16 | Jul 28–Aug 4 |
| 7a & 7b | Jan 30–Feb 6 | Apr 24–May 1 | Jul 13–Jul 20 |
| 8a & 8b | Jan 14–Jan 21 | Apr 8–Apr 15 | Jun 27–Jul 4 |
| 9a & 9b | Dec 7–Dec 14 | Mar 1–Mar 8 | May 20–May 27 |
| 10a & 10bSpring window | Jan–May | Mar–Jul | ~80 days after transplanting |
| 11a & 11b | Oct 23–Oct 30 | Jan 15–Jan 22 | Apr 5–Apr 12 |
Bloom dates are about 80 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
No well-established companions for vinca (Madagascar periwinkle).
Where to buy vinca seeds
True Leaf Market · Burpee (each supplier's vinca seeds)
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing vinca (Madagascar periwinkle)" 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 →
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Growing Vinca (Madagascar Periwinkle) in USDA zone 5b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
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