Dipladenia is actually a member of the mandevilla family. It is widely thought that mandevilla and dipladenia are the same plant. While they are similar, dipladenia foliage is somewhat smaller and the plant is more shrub-like. However, both plants have the same care and growth requirements.
Dipladenia vs. Mandevilla
Both dipladenia and mandevilla are tropical plants with beautiful showy flowers. The blooms can be red, pink, or white, depending on the variety, and will be trumpet-shaped, reminiscent of a hibiscus. Both plants are hardy and perennial to USDA zones 9 or 10 and are popular annuals in northern regions where they can be overwintered.
The differences between the two plants begin with the way they grow. While mandevilla will vine out—sometimes over 20 feet—dipladenia will be more of a bush, though it may produce a short vine. If you're looking for a trellis or arbor flower mandevilla is the one you want. For a full patio container or hanging basket that will bloom all summer, go with dipladenia.
There is also a slight difference in the foliage and flowers. Dipladenia have wide leaves that grow into a heart shape and are smooth. Mandevilla leaves are thin, long, and textured.
To see the difference in the flowers, you will likely need to compare the two plants side by side. The shapes are generally the same, though the dipladenia's flowers will be smaller. Both flowers are attractive to hummingbirds and butterflies as well.
Dipladenia and mandevilla will flower best in full sun—six to eight hours a day—but will tolerate part shade. One of the perks of planting them in containers is the ability to move of your plants as needed. If you live in a really hot area, for instance, try moving your plant to a shady spot in mid-day to ensure the leaves don't get scorched.
Drainage and Watering
Unlike many flowering plants, dipladenia or mandevilla will tolerate some dryness and continue to flower. That said, they prefer a consistent level of moisture and you should try to keep the soil damp, but not wet.
When watering, make sure to water slowly to give the soil time to soak up the moisture. When using a hose, spray the leaves too. Also, make sure that your pot has good drainage and that you use a good quality potting mix.
For a consistent production of flowers, don't transplant your dipladenia into a container that is too large. If you do, it won't hurt your plant, but it will spend more energy producing roots and top growth than flowers. You may see fewer flowers until the roots have hit the bottom of the pot.
If your plant becomes root bound and does need a bigger pot, look for one that is wider, but not much deeper. This will allow the roots new room to grow as needed while allowing much of its energy to be put toward the blooms.
Mandevilla and dipladenia look great on their own in a pot or as the centerpiece of a mixed container. They look fantastic in a large pot and you can give them a trellis or obelisk to climb. They're also showy when surrounded with a contrasting annual or foliage plant. You might even try them in unique plantings, such as in pots with oregano and coleus.
Most plants you buy at the nursery have a slow release fertilizer already in the soil. You probably don't have to worry about feeding your plant for the first few months. After that, you will need to fertilize it regularly.
You can either use a diluted, plant food every other week or add a slow release fertilizer to your soil. Always follow directions on the package.
If you live in a cold climate (anything lower than zones nine through 11), it is possible to overwinter dipladenia indoors.
- Take your plant in before evening temperatures dip below 50 F.
- Put it in a place with as much direct sun as you can, though it may even survive if you can provide lots of indirect light.
- Dipladenia doesn't like the cold so protect it from drafts.
- Don't be alarmed if your plant doesn't flower or sheds some leaves in the winter.
- In the fall, you may see long shoots or sprouts. You can trim these back lightly or train them onto a trellis or support.
- Stop feeding through the winter.
- Though plants generally need less water in the winter, central heating can dry the air and your plant very quickly. Keep your plant on the dry side during the cold months, but make sure it doesn't dry out too much.
- In the spring, increase watering and resume fertilizing.
- Don't cut the plant back, or you will miss out on next seasons flowers.
- You can put your plant outside once the nighttime temperatures are consistently above 50 F.
Pests and Diseases
In terms of pests and plant diseases, spider mites, mealy bugs, fulsarium, and cercospora are the most common problems you may run into. The sooner you can spot these and deal with them, the healthier your plants will be.