How to Grow Morning Glories

Morning glory flowers with light purple petals hanging in front of large leaves

The Spruce / Gyscha Rendy

As familiar with morning glories as folks are in North America, these fascinating flowers hold many secrets for the casual gardener. Morning glories are annuals that belong to the same family as the sweet potato, but the morning glory plant is not edible; in fact, its seeds are toxic. The vines, with their characteristic trumpet-shaped blooms, can grow more than 10-feet in a single season.

Fast-growing morning glories are planted in spring, typically from seed, and they climb by means of tendrils that can cling to a trellis, fence, or wall with ease. If you live in a warm winter climate, your morning glories may be perennial, but otherwise, you can usually count on new "volunteer" plants sprouting up from seeds dropped by last year's plants; these are excellent self-sowers

Morning glories get their name from their fragrant blooms that remain tightly furled until they awake and open up in the morning sun then close again in the afternoon before dying (each bloom lasts only one day). Not surprisingly, these big, sweet-smelling flowers are favorites of hummingbirds, butterflies, and other pollinators.

Botanical Name  Ipomoea purpurea 
Common Name  Morning glory
Plant Type  Annual vine 
Mature Size  6-10 ft. long, 3-6 ft .wide 
Sun Exposure  Full sun 
Soil Type  Moist, well-draining 
Soil pH  Acidic to neutral (6.0 to 6.8) 
Bloom Time  Summer, fall 
Flower Color  Purple, pink, blue, white, red
Hardiness Zones  2-11 (USDA) 
Native Area  North America, Central America 
Toxicity  Toxic to humans and animals 

Morning Glory Care

Morning glories are easy to care for. They do not need deadheading, which is good because they bloom profusely. Start with seeds or seedlings, and plant them next to a fence, wall, arbor, or other structure, and they'll make their way up. Sometimes referred to as the back-to-school vine, suggesting a bloom time that might wait until the end of summer. If late-season blooms are common in your area, try starting some seeds indoors before the last frost to get a jump on the season.

A popular use for morning glory vines is as a privacy screen when grown upon lattice or chain-link fencing. It is also common to see morning glory vines growing on trellises and arbors. If you can get them to cover an arbor completely, they will offer shade in late summer. These vines are often grown in containers, as are various other kinds of Ipomoea.

Morning glory flower with light purple trumpet-like petals closeup

The Spruce / Gyscha Rendy

Morning glory flowers facing left with white and pink trumpet-like petals

The Spruce / Gyscha Rendy

Morning glory flowers with trumpet-like purple petals on large leaves

The Spruce / Gyscha Rendy

Light

Grow morning glories in full sun and well-drained soil. Direct sun exposure is what makes the blooms open and stay open. Planting them in part-sun conditions may mean they won't bloom until later in the day, which shortens the already short life of the one-day flowers.

Soil

Morning glory vines tolerate poor soil, but they prefer moist soil that drains well and is slightly acidic to neutral, with a soil pH of 6.0-6.8. Moderately rich soil does not need amending prior to planting, since morning glories don't like it too rich. If necessary, you can add organic matter if the plants seem to need it.

Water

Your vines should get about 1-inch of water per week, or whatever is required to keep the soil moist (not wet). In dry areas, a layer of mulch over the root area helps retain moisture and reduce watering needs.

Temperature and Humidity

Morning glory vines can thrive in a variety of temperature and humidity conditions, but they are not frost-tolerant. Seedlings should not be planted outdoors until the soil is 64 degrees Fahrenheit or warmer. Seeds can be planted before the last frost.

Fertilizer

Morning glories generally benefit from a monthly feeding of low-nitrogen fertilizer. Too much nitrogen promotes leave growth at the expense of blooms, while feeding with a fertilizer high in phosphorous can promote blooms on lackluster plants.

Is Morning Glory Toxic?

While morning glory plants and flowers are not toxic, the seeds are poisonous, especially when ingested in large quantities. The seeds contain an alkaloid that causes similar effects to the drug LSD, in addition to more dangerous potential symptoms.

Symptoms of Poisoning

If a person has eaten morning glory seeds, they may experience hallucinations, increased heart rate, numbness in limbs, tingling, stomach upset, or muscle tightness. Call 911 immediately. Animals that eat morning glory seeds may experience a lack of coordination, stomach upset, or agitation. Call your veterinarian immediately.

Morning Glory Varieties

  • Ipomoea tricolor 'Heavenly Blue': A popular cultivar with large, azure flowers and heart-shaped leaves
  • Ipomoea alba: Also called moonflower or belle de nuit; a night-blooming species with 6-inch-wide white flowers
  • Ipomoea x multifida: Known as the cardinal climber; a hybrid with relatively small but deep red flowers resembling morning glory blooms
  • Ipomoea purpurea 'Star of Yelta': Deep purple blooms with dark red stars and small white throats
  • Ipomoea purpurea 'Kniola's Black': Another purple-flowered cultivar of Ipomoea purpurea but with blooms even darker than those of 'Star of Yelta'

Pruning

Most people let their morning glories grow wild, but that doesn't mean you can't give yours a trim to help them from overcrowding. First, untangle the wines and separate them, so each one gets plenty of sunlight. Then, prune back 1/3 of them, just past the first leaf bud, to encourage rapid growth and more excessive blooming.

How to Grow Morning Glories From Seed

Morning glories are considered fast-growing vines, but they can take a long time to flower (August, in the North) if not grown under ideal circumstances. You can encourage earlier blooming by starting morning glory plants inside from seed in peat pots filled with potting mix, then transplanting them outside after all danger of frost has passed.

Sow the seeds indoors about three weeks before the estimated last frost date in your region. Keep seeds damp for 24 hours before planting, and lightly scar the surface. Plant seeds a bit less than 1/2-inch deep and cover them with potting mix. Keep potting mix damp and warm (at least 70 degrees Fahrenheit).

If these sun-loving vines are started from seed indoors and given plenty of sunlight (southern or western exposure) and adequate water once planted outdoors, even in the North they should bloom by early July. 

Seeds can also be direct-sown into the garden, once the soil reaches 64 degrees Fahrenheit. Space the seeds about 6-inches apart in rows, or space them closer together if you plan to train them up a trellis. You can speed germination by scarifying the seed. Rub the seeds between sheets of coarse-grit sandpaper, then soak them in water overnight before planting.

Common Pests/Diseases

Spider mites and several animal pests can pose problems for your morning glories. When you detect insects, spray with organic neem oil. To deal with heavy pressure from deer and other animals, such as rabbits and groundhogs, erect deer fencing or apply repellents. Fencing needs to extend only about 3-5 feet from the ground and will eventually be hidden by the plant foliage, although vines growing through the fencing can be eaten by animals.

Overly wet weather can lead to problems with fungal diseases, including thread blight, white blister, stem rot, and leaf spot. To fight fungal disease, trim away affected areas and use fungicides.