Common morning glory (Ipomoea purpurea) — care & requirements

In short

The flowers open in the morning and wilt by the afternoon of the same day — each flower lives only one day.
An annual plant of very rapid growth that can cover a trellis or fence in the course of a single summer.
It twines around its support — it needs a trellis, cords or stakes.
The seeds are toxic and contain psychoactive compounds — keep away from children and animals.
It flowers abundantly from July until the first frosts.

Botanical data

Family: Convolvulaceae (Convolvulaceae)
Height: 2–4 m
Width: 0.3–0.6 m
Habit: Cascading
Growth rate: Fast
Position: Full sun
Soil: Loamy, Sandy, Humus-rich
pH reaction: pH 6–7.5
Moisture: Moderate, Dry
Bloom: July–October
Hardiness: —
Propagation: From seed

Characteristics

A hairy, twining stem with heart-shaped leaves and funnel-shaped flowers 5–8 cm in diameter, opening singly in the leaf axils. The flowers are typically purple-violet, but garden cultivars also offer pink, blue and white, often with a lighter star at the throat.

Growing and care

Watering

Fairly drought-resistant once established; excessive watering and overly fertile soil stimulate leaf growth at the expense of flowering.

In summer every ~5 days · drought tolerance: High

Fertilizing

Poor to moderately fertile soil promotes more abundant flowering than overly fertilised soil.

once per season, at planting · kompost w niewielkiej ilości

Planting

Before sowing, lightly nick or soak the hard seed coats to speed up germination; provide a trellis, cords or stakes immediately after sowing.

Timing: May, after the frosts have passed · spacing 20–30 cm

Pruning

Cut back overgrown or dense shoots to improve ventilation and direct growth onto the desired support.

Timing: As needed, on an ongoing basis during the season. · Caution: Regular pruning is not necessary — the plant dies with the first frosts anyway.

Companion plants

Good companions

Common sunflowerPractical observation

The tall, stiff stem of the sunflower can serve as a living, natural support for the twining shoots of the morning glory.

Sweet cornGardening tradition

A traditional combination known from cottage gardens — the tall maize stalks give support to the light shoots of the morning glory.

Bad companions

Low, delicate annual plants in the immediate vicinityPractical observation

The very rapid growth of the morning glory allows it to entangle and shade weaker, lower-growing neighbours in a short time.

The evidence level indicates whether the relationship is backed by research, observation, or gardening tradition.

Toxicity

For whom	Level	Notes
Humans	Moderate	The seeds contain LSA-like alkaloids with a psychoactive and toxic effect — ingestion risks poisoning, nausea and neurological disturbances.
Dogs	Moderate	—
Cats	Moderate	—

History and origin

Cultivated ornamentally since colonial times, when it reached Europe from Central America. In many warmer regions of the world, including the southern USA, it has escaped cultivation and is sometimes regarded as a troublesome garden weed; in the Polish climate it dies with the first frosts and poses no invasive threat.

Uses

For the fast, seasonal greening of trellises, fences, balcony railings and pergolas where an immediate, dense screen is needed within a single summer.

Trivia

The genus name Ipomoea derives from the Greek “ips” (worm) and “homoios” (similar), alluding to the twining, worm-like shoots.
The daily morning opening of the flowers and their wilting in the afternoon is a typical feature of the entire genus Ipomoea, from which the English name “morning glory” derives.

Frequently asked questions

Why do morning glory flowers wilt by the afternoon?

This is a natural feature of the species — each individual flower lives only one day: it opens in the morning and wilts after a few hours, usually during the same afternoon. The plant compensates for this by abundantly producing new buds every day throughout the flowering season.

How do you speed up the germination of common morning glory seeds?

The seeds have a hard, impermeable coat, so it is worth lightly nicking them with a file or soaking them in water for 24 hours before sowing — this considerably speeds up and evens out germination.

Is the common morning glory dangerous to children or animals?

The seeds contain alkaloids with an effect similar to LSD, toxic if eaten — they can cause poisoning and neurological disturbances. It is worth making sure that children and pets have no access to them, especially in autumn when the seeds ripen.

Sources

Plants of the World Online (POWO)Database (GBIF, POWO…)
Missouri Botanical Garden — Ipomoea purpureaInstitution / botanical garden

Edited by:Redakcja Atlas-Flora. Updated: 7/14/2026.

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Common morning glory