Morning glory: sowing, winter hardiness & toxicity of Ipomoea tricolor

Morning glory is particularly popular because of its bright blue flowers. It is not hardy but with a little patience it can be easily sown.

Morning glory is excellent as greenery for facades or as a screen for fences. Read here about its toxicity and how you can easily propagate, plant and care for it.

Morning glory: origin and characteristics

Ipomoea tricolor, also known as Heavenly Blue or Mexican morning glory, is native to Mexico and Central America and belongs to the bindweed family (Concolvulaceae). Translated, “convolvere” means “to wind around or entwine”, which describes the ability of this species. Known edible relatives of morning glory include the sweet potato (Ipomoea batatas) and water spinach (Ipomoea aquatica). Purple morning glory (Ipomoea purpurea) is also used as an ornamental climber.

Ipomoea tricolor climbs successfully due to its long, twining shoots. If you do not provide morning glory with a climbing aid, it will grow to cover the ground. The climbing plant, which can reach a height of 3.5 m, forms entire, heart-shaped leaves and flowers from June to September. Its funnel flowers are a lovely blue and have a white throat in the centre. The cultivars now offer gardeners varieties with white to pink flowers. Their flowers open in the morning and fade the same day. Fortunately, the plant is very active in flowering, which is why the short flowering time of the individual morning glory flowers does not hinder its ornamental appeal. It is used in cottage gardens as a screen for fences, hanging basket plant, container plant or as greenery for facades. The magnificent morning glory is less interesting to insects because it offers little pollen and nectar.

Is morning glory perennial? No, it is a frost-sensitive, climbing plant. Therefore, it is almost always cultivated as an annual here. In its native habitat, morning glory lives perennially although it is not thought to be long-lived.

The most beautiful varieties and species of morning glory

Ipomoea tricolor in its wild form is best known for its sky-blue flowers. However, new varieties of morning glory can offer beautiful and colourful alternatives. We have put together a nice selection for you.

• ‘Heavenly Blue’: has long been part of the standard assortment of every perennial nursery and seed business. It boasts strong blue funnelled flowers that appear from July to November. It can reach a height of around 3 m.

• ‘Grandpa Ott’: differs from the standard variety with its blue-purple flower pattern and light purple throat. This variety flowers from July to October and reaches a height of 2 m.

• ‘Flying Saucers’: the beautifully coloured, white flowers with sky-blue patterning look good on house walls or in hanging baskets. It can reach up to 2 m in height and flowers from July to October.

• ‘Pearly Gates’: radiates with its pure white flowers from July to October. It can reach a height of 2 m.

Planting morning glory: location, sowing and more

Morning glory is a sun-loving and heat-loving climber, although it also tolerates partial shade. For maximum flowering, the right soil conditions are highly important – these should be permanently fresh, well-drained and rich in nutrients. In addition, morning glory does not tolerate waterlogging as this can cause fungal diseases and root rot. Even brief dry spells and root competition from large shrubs or woody plants lead to stunted growth. The soil should also be chalky and therefore not too acidic. A soil pH test can be carried out to find out whether and to what extent the soil is acidic. For sandy, light soils, a pH value of 5.5 to 6.0 is optimal; for clayey, heavy soils a value of 6.5 to 7.5 is ideal. If the measured value is below this, use some garden lime to raise it.

After watering well, the pH value is brought back into balance. However, because of the calcium it contains, it should never be fertilised at the same time as nitrogen or phosphate fertiliser. Calcium interacts undesirably with both nutrients, resulting in nutrient loss or environmental pollution.

Pre-cultivate in March on a windowsill or under glass at a temperature of 18 to 20 °C. In order to successfully germinate the hard-shelled morning glory seeds, they can be slightly roughened and soaked overnight. Press the seeds 1 cm deep into the soil. For growing, we recommend a substrate that is as low in nutrients as possible. For example, you can use our Plantura Organic Herb & Seedling Compost, which is specially designed for the needs of young plants. It is lower in nutrients, which stimulates strong root development of seedlings and young plants.

Organic Herb & Seedling Compost, 20L

(4.8/5)

• Perfect for herbs as well as sowing, propagating & transplanting
• For aromatic herbs & healthy seedlings with strong roots
• Peat-free & organic soil: CO₂-saving composition

£12.49

Shop now!

Two to three seeds per seed pot are used, which should germinate within two to four weeks at the most. Keep the substrate constantly moist, but not too wet. When the first true leaves develop, the seedlings can be planted individually. This prevents the twines from getting caught in each other. Add a climbing aid in the form of a small stick. When there is no longer a threat of frost and the last cold nights are over, the frost-sensitive climbing plant can be planted outside. The morning glory then needs enough planting space of 40 to 50 cm. It likes to stand alone but at most in small groups of three to five plants. Place a drainage layer of gravel, for example, to prevent waterlogging.

It is not uncommon to see the morning glory cultivated in pots or hanging baskets. Make sure that the pot diameter is about 30 cm and that there is a water drainage hole. Drainage can be optimised by placing clay shards at the base of the pot. For potted plants in particular, a nutrient-rich substrate should be used after growing, such as our Plantura Organic Flower Compost. This has an optimal pH value of 5.6 to 6.4 and does not require any peat. The expanded clay also prevents waterlogging.

Note: after the last frost has passed in May, the plants can also be sown directly in the open, although this causes the morning glory to flower later.

Morning glory care

Ipomoea tricolor should always be kept moist – morning glory does not tolerate drought. Well-drained soil prevents unwanted waterlogging.

Support morning glory with regular, potassium-based fertilisation. Our Plantura Liquid Flower Food quickly releases nutrients, including potassium, to the plant. It is also low in phosphorus which conserves resources and does not impair the growth of the morning glory, as a high-quality potting soil provides the climbing plant with sufficient phosphorus.

Liquid Flower Food, 800ml

(5/5)

• Perfect for all flowers & balcony plants
• Liquid fertiliser for a lush blossom throughout the season
• Quick & easy application - child & pet friendly

£10.99

Shop now!

Possible pests include spider mites (Tetranychidae). Spider mites love a warm location, as does morning glory, which is why they are unfortunately commonly infested. In this case, predominantly biological pest control is recommended with preparations based on rapeseed oil or potash soap. If possible, the plant should also be isolated to prevent it from spreading.

Tip: morning glory is very tolerant of pruning. If you want a bushier growth, the tips of the shoots can be pruned well – two new shoots are usually produced per cut.

My morning glory will not flower: what to do? If your morning glory does not flower, this could be due to a location that is too shady and unprotected. Check the permeability of the soil, too. This should be loose enough to provide enough oxygen for the roots. A pest infestation by spider mites could also be the reason for a lack of flowering.

Is morning glory hardy?

No, morning glory is not hardy in our country. However, overwintering is possible at a temperature of 15 °C, although this prevents flowering the following year. Since morning glory is easy to sow, it is usually not worth the effort of overwintering.

Tip: to make an overwintered morning glory bloom again, pot it in fresh substrate after overwintering in April, provide it with a starter fertiliser and prune if necessary. This way it can soon sprout anew.

Propagation

The best way to propagate morning glory is by seed. Morning glory is rarely cross-pollinated and instead pollinates itself, which is why the offspring usually resemble the mother plant. In autumn, spherical fruits with dark seeds emerge from the flowers. At first, the fruits remain green: as soon as they are brown and dried, harvesting can begin. Store the morning glory seeds in a dark, dry place until sowing in March.

Note: the seeds of Ipomoea tricolor are poisonous, so it is strongly recommended to wear gloves when harvesting.

Is morning glory poisonous?

Yes, morning glory is poisonous. It contains lysergic acid amide, a substance closely related to lysergic acid diethylamide (LSD). The highest concentration is found in its fruits and seeds. This substance is particularly dangerous for children and pets. The toxin results in a hallucinogenic and psychedelic effect, which can vary greatly according to the state of maturity. A general statement about its intensity can therefore not be made.