A Tropical Summer Bloomer but is it a Mandevilla or a Dipladenia?

Dipladenia ‘White Halo’ in my garden

Both mandevilla and dipladenia plants are popular tropical plants. They bloom all summer long in full sun, undaunted by dry spells.  The flowers are trumpet-shaped, in a range of white, pink, reds, yellow and even peach.

But there is one distinct difference between the two plants.

Mandevilla with hoya-like foliage

Mandevilla is a vining plant; it climbs up to the sunlight. You purchase it with the intent to cover an arbor, pergola, or obelisk. The stems and foliage remind me of a hoya plant (in fact, they are cousins). The leaves seem larger than the dipladenia, pointed and glossy. However, if you purchased a mandevilla and would like to grow it as a shrub, you can just prune it.

A dipladenia is a shrub. It will not climb up a structure. This makes it perfect for containers and hanging baskets. The foliage is smaller, more compact, and more matte than glossy. The space between nodes (joints where leaves arise) is shorter than the mandevilla. It is more of a slow grower while a mandevilla will grow fast to cover a structure. Although they both have trumpet-shaped flowers, to me the dipladenia flowers appear flatter with a shallow throat.

Dipladenia with compact foliage

Both need to be in full sun, and are drought tolerant with no need to deadhead. They attract pollinators and are deer and rabbit resistant.

As fall approaches, they can be kept overwinter in order to plant in the garden the following year (these are not cheap plants). There are several ways to do this depending on the space and light in your house. You can root 4 to 6-inch stem cuttings and grow them inside as houseplants. You can give your plant a good trim in the fall, up to one half of the foliage to reduce transpiration, bring the plant in and place in a sunny, cool location and water less often. Or you can cut the foliage back severely, place the plant in a cool, dark place and stop watering. Let it go dormant for the winter but check on it so it does not dry out completely.

Don’t be surprised if containers of mandevilla and dipladenia get mixed up at the local garden centers. Most people do not recognize the difference. Regardless, they are great investments for constant summer blooms especially when we have dry summers such as this one.

Mandevilla