What Is Dipladenia, and What Makes It Different from Mandevilla? by Alyssa Brown:
“Dipladenia is a flowering plant you’ve likely seen before, either at your local nursery or growing in a friend’s pollinator garden. Most recognizable for its bushy leaves and trumpet-shaped flowers, this tropical plant thrives in pots, in the ground, and in hanging baskets. Horticulturist and gardening expert Melinda Myers has been growing dipladenia for about 30 years — ahead, she shares everything there is to know about the plant, including what makes it different from its relative, mandevilla.
“‘Dipladenia is botanically in the mandevilla genus, but they used to be separate,’ says Myers…. The two names are commonly used interchangeably, she says, but there are some differences between the plants. Dipladenia, for example, tend to be more shrub-like in appearance, with smooth, glossy leaves, while mandevilla has longer, thinner, textured leaves that are less bushy; this plant looks more like a vine. Both plants’ flowers are similar, but dipladenia blooms are often smaller — plus, this iteration changes all the time, thanks, in part, to its popularity: Growers are regularly introducing new varieties, some of which include new bloom colors, larger blooms, denser foliage, or types that act more like a vine….”
As you might have gathered from the title (and the quote above) the flowering plants featured in this post (and the next two posts) are called: dipladenia, a nice roll-off-the-tongue kind of name that you might find hard to say if you were drunk. Over the years, I’ve alternated between buying dipladenia or their relative mandevilla every spring: sometimes, I buy whichever one I find first at the garden centers; other times, I’ve bought them specifically for smaller pots so wait until the little dips are available. Despite some naming confusion, mandevilla is usually associated with larger vines, typically sold in a big pot with the vine already heavily entangled on a plastic or bamboo trellis. Both are very common and grow quite rapidly here in the southeast; the smaller, bushier plant — the dipladenia — works quite well on the back steps leading to my courtyard, and, unlike the mandevilla vine, never grow so long that they need frequent pruning or manual detachment from whatever structure happens to be nearby.
Both plants are annuals, and, from my experience, they’ll flower well into fall, even if there are plenty of cold nights. By now — mid-November — flowering tends to stop, but their hardy vines and leaves will keep on growing (a bit more slowly) through much of the winter unless there’s a multi-day stretch of temperatures well below freezing, and then all the leaves fall off. Despite their small size, they produce an enormous volume of roots: when spring comes and I replace them, I get to cuss profusely as I cut and tug and pry the roots out of the pots and always wonder where all the soil went.
Despite having a big batch of plant, gardening, and botany books, I didn’t find any references to either plant, the plants’ family name (Apocynaceae), or some of their common names (rock trumpet, rocktrumpet, or trumpet vine, and possibly (from the olden days yore) dogbane), which led me to dig around on the internet and find an equally small amount of information. Perhaps I’ll keep digging — note to self: watch out for rabbit holes! — but, for now, we’ll just have to enjoy the pictures. These are the red ones (sold as “Dipladenia Rio Red”). In the next post, I’ll feature white ones (my favorite of these flowers); and in the last post, I’ll upload a handful of each on black backgrounds.
Thanks for taking a look!