Moonflower in Zone 4a & 4b
Ipomoea alba
When to plant moonflower in zone 4b
Zones 4a and 4b share the same average frost dates in our data, so this page covers both.
Method: Either: Start indoors for an earlier harvest, or direct-sow outside for less fuss. Moonflower tolerates either.
| Start indoors | Apr 10–Apr 17 |
|---|---|
| Direct sow / transplant outside | May 15–May 22 |
| Estimated bloom | Aug 13–Aug 20 (~90 days after planting) |
Spacing: 2 per square foot (square-foot-gardening spacing). Mature height: 10-20 ft.
Moonflower is a morning glory that runs on the opposite schedule. The flowers, white trumpets six inches across, open in the late afternoon and close at dawn, and they're scented for a pollinator most gardeners never see: hawkmoths and sphinx moths, working the plant after dark. If you sit outside on a summer evening you can sometimes watch a bud unwind in a couple of minutes.
How moonflower fits zone 4's season
Zone 4b's frost-free window runs about 128 days, from May 15 to September 20. Moonflower needs about 90 days from sowing to first harvest.
Good companions
No standout companions recorded yet for Moonflower.
Where to buy moonflower seeds
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing moonflower" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 4b calendar · Full companion planting guide · Full plant profile · Plan your beds in the Garden Designer →
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Growing Moonflower in USDA zone 4b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
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