Front
Climbing annualFrom seed
Ipomoea tricolor
Heavenly Blue morning glory
Sky-blue trumpets, open each morning, gone by evening
Back
Sowing & growing
| Task | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sow indoors | April | May | ||||||||||
| Plant out | May | June | ||||||||||
| In flower | July | August | September | October |
- Sow
- indoors, 3 to 4 weeks before planting out
- Seed
- nick the coat or soak overnight first
- Depth
- about 6 mm
- Warmth
- around 18 °C or a little more
- Plant out
- after the last frost, in full sun
- Support
- canes, wire or netting; it twines
- Height
- 2.5 to 4 m in one season
- Flowers
- open in the morning, fade by evening
Folded inside the packetUpdated
Heavenly Blue is the best-known cultivar of Ipomoea tricolor, a climbing morning glory from Mexico with sky-blue flowers up to 8 cm across that open in the morning and fade by evening. In gardens with frost it is grown as an annual from seed, sown indoors in spring and planted out after the last frost. It holds the Award of Garden Merit of the Royal Horticultural Society, and seed catalogues have sold it under this name since at least the early 1940s.
The plant has a second reputation. Its seeds contain small amounts of ergoline alkaloids, chiefly ergine (LSA), made by a fungus that lives inside the plant. In 1960 the chemist Albert Hofmann identified these compounds in morning glory seeds from Oaxaca, where Zapotec healers used them in divination rites. A few years later American doctors reported the first cases of people harmed after swallowing garden seed.
What this site covers
- The plant: the species, why the flowers turn blue as they open, the old confusion with Ipomoea violacea, and what is documented about the cultivar's origin.
- Growing: sowing, the hard seed coat, support, why flowering starts late, and keeping seed away from children and pets.
- The seeds: which alkaloids are in them, how much the content varies between packets and single seeds, and the fungus described as a new species in 2025.
- Risks: what is on record about swallowing the seeds, the story about coated seed and what the law says about treated seed.
- History: ololiuqui and tlitliltzin in colonial records and in Oaxaca around 1960.
- Legal status: LSA and the seeds in eight countries and one US state, checked in the law texts on 10 October 2026.
What this site does not do
It gives no dosing, preparation or extraction information, and it links to no products. Morning glory seed is garden seed and not food. The RHS classes the plant as harmful if eaten, for people and pets. If you grow it, you are growing one of the most popular annual climbers of the past century, and that is the use this site is written for.
The site is published by the team behind Dutch-Smart, a Dutch smartshop. The about page explains why that is relevant and how the information was checked.