Plant morning glory after frost, once the soil is warm. Nick the seed, soak it, and sow it at the base of a trellis already in place.
Sow after frost, once the soil is warm
| Factor | Recommended | Avoid |
|---|---|---|
| When | After the last frost, soil about 60 to 65°F | Cold, wet ground that rots soaked seed |
| Seed | Nick the coat, then soak 12 to 24 hours | Sowing hard, dry seed in a hurry |
| Depth | About ¼ to ½ inch | Deep burial that stalls the sprout |
| Support | Trellis or fence already standing | Driving stakes after vines have tangled |
Morning glory is frost-tender. Wait until nights stay above freezing and the soil has warmed. [1] [2] [3] Heavenly Blue and other climbing types sow the same way. moonflower can start indoors 4 to 6 weeks before frost if your season is short; climbing types are happier sown outdoors.
When should I plant morning glory?
After the last frost, when the soil is about 60 to 65°F. Cold soil rots soaked seed.
How to plant morning glory
Set the support first. Then prepare the seed and sow at its base.
- Install a trellis, fence, or netting where the vines will climb. Do not wait until stems are already tangled.
- Nick each hard seed coat with a file or sandpaper, or clip a tiny corner. Do not cut into the inner seed.
- Soak the nicked seed in water 12 to 24 hours. Sow as soon as it swells. Do not let it dry out again.
- Sow about ¼ to ½ inch deep, 6 to 12 inches apart, at the base of the support. Water to settle.
- Keep the top moist until seedlings show, usually in one to two weeks.
Do I soak morning glory seeds?
Yes. Nick the hard coat, then soak 12 to 24 hours. That speeds germination.
What fails at planting
Soaked seed in cold soil rots. Seed sown without a nick can sit for weeks. A trellis added later breaks stems. Indoor starts race up a windowsill before the garden is warm — direct sow unless you are giving moonflower a head start in a short season.
- Do not sow into soil colder than about 60°F.
- Do not skip the nick and soak on old or very hard seed.
- Do not bury seed deeper than about ½ inch.
- Do not leave a gap with no support at the sowing line.
How deep do I plant morning glory seeds?
About a quarter to a half inch. Deeper sowing slows or stops the sprout.
If soaked seed sat in cold soil and never came up, wait for warmth and sow a fresh batch — do not waterlog the first row hoping it will catch.
FAQ
Should I start morning glory indoors?
Direct sow after frost for climbing types. Indoor vines outgrow pots fast. Moonflower can start 4 to 6 weeks early if your season is short.
Can I sow ornamental sweetpotato vine from seed the same way?
No. Foliage vine starts from a cutting or a tuber on How to Grow Sweetpotato Vine. A food crop starts from slips on Planting Sweetpotato.
Related guides
Recommended plants
References
- [1] Eden Brothers -
https://grow.edenbrothers.com/planting-guides/morning-glory-seeds/ - [2] Old Farmer's Almanac -
https://www.almanac.com/plant/morning-glories - [3] Oregon State University Extension Service -
https://extension.oregonstate.edu/catalog/em-9880-growing-annual-morning-glory - [4] NC State Extension Gardener -
https://plants.ces.ncsu.edu/plants/ipomoea/
This note is part of Ipomoea Guides.
More planting notes by plant are gathered in Planting Guides.
Updated: Reviewed by Bosquelle Editors