Try these showy flowers for blooms all summer in your North Texas garden
You can have your bougainvilleas. I’ll let you coax them to bloom. Some of my friends have better luck than I do.
Give me mandevillas any day and I’ll show you flower power all summer. This beauty from Rio arrived in full bloom, and it hasn’t let up since. Except for our winters, of course. After all, it’s a tropical.
I have to think back to when I first saw this plant in the nurseries. It was the simple pink type, and that was probably 45 years ago. I know right where I was standing. Little by little it caught the eye of Texas gardeners and you’d see them plant it as a hot weather annual along fence posts or in patio pots with trellises. It would be in flower when they planted it, and it would still be blooming when the first frost approached in the fall. We all fell in love with the plant, and it’s never fallen from favor.
Names began to get thrown around. At first we just called it by its generic name mandevilla. Then the genus Dipladenia started showing up on nursery labels. Later the name Mandevilla splendens was assigned to it as well. Eventually the botanists settled on Mandevilla sanderi of the family Apocynaceae, and seems to be where things have ended up for now. Other members of that significant horticultural family include plumerias, oleanders, and periwinkles. Now that you know that, you can see it in their flowers. They do indeed bear a striking resemblance.
In recent years there has been a lot of hybridization done with mandevillas, and that’s where things have gotten really exciting. Compact, pink-flowering forms have been developed, as well as white and bright red types. We now have fully double-flowering varieties, too. You can only imagine what is out there in the plant breeders’ pipelines. And the good news is that when they find something superior, it takes no time at all to build up big numbers via cuttings. So, while I know nothing specific about what’s coming along, my guess would be that we should be prepared for some fun times ahead. The best is yet to come with mandevillas.
Facts to know about mandevillas
Mandevillas are of tropical origin, specifically Rio de Janeiro, Brazil. They grow to 8 to 12 feet tall and 3 to 4 feet wide when given proper support so that they can climb by their vigorously twining stems.
The plants produce relatively large (3 to 5 inches) glossy green leaves that are evergreen when grown in frost-free surroundings. The plants are winter hardy only in Zones 10 and 11 where temperatures stay above freezing. In our area you will have to use mandevillas as summer annual vines or be prepared to overwinter your plants in a greenhouse or spacious, very bright sunroom.
Mandevillas grow best in full morning sun, with protection from the hottest sun or mid-afternoon in the summer. Plant them into well-prepared, highly organic planting soil and keep their soil moist at all times. They will do best if given a complete and balanced, water-soluble plant food once a week.
The large, tubular flowers of mandevilla blooms are showy to say the least. You’ll find them sold in a bright, clear pink, also white and bright red. Most will have golden yellow throats, making them all the more attractive to hummingbirds and butterflies. Grown on a tall support in the center of a butterfly garden, they’ll be the showstoppers of the entire planting.
Few insect or disease problems will bother your mandevillas. From my own personal experience, the only pest that has stopped by to visit my own plants was a crop of mealybugs one season when I took several big plants into my greenhouse. I soon learned that it would be easier to deal with them early on than to cure a big outbreak once it had built up speed. Mealybugs look like small chunks of popcorn stuck in the axils of leaves and along the plants’ stems.
Mealybugs are soft-bodied scale insects. Left uncontrolled they can quickly become ugly and hard to eliminate. Many general-purpose organic and inorganic insecticides will eventually get rid of them, or if you only have a few you can daub them off with a cotton swab dipped in rubbing alcohol. Persistence is the byword, however, so again, keep after them if you see them.
Unless you’re doing breeding work and planting seeds to develop new varieties, mandevillas are propagated by stem cuttings. Each cutting should be 4 to 6 inches long and should have two or three pairs of leaves. Carefully remove the pair closest to the base of cutting since you’ll be inserting it into your potting soil.
If the outer tissues on the stem have become at all woody, use a sharp knife to scratch the wood off the outer surface. It may be easier to take a single-edge razor blade to cut a sliver of the outer tissue away. That wound will expose more surface area from which roots can develop.
Dip the freshly wounded cutting into rooting hormone powder. Tap off the excess and stick your cuttings into a 6-inch flowerpot filled with very loose, highly organic rooting mix that you have pre-watered. I like to use 50% sphagnum peat moss and 50% perlite, and I use a thin pencil to make an insertion hole so I don’t wipe off the rooting hormone powder.
Water the new cuttings, then cover them loosely with dry cleaner’s plastic and set them in a bright spot out of direct sunlight so they don’t overheat. They should begin to form roots within 2 to 4 weeks at which you can pot them up individually and grow them for several weeks before planting them into their permanent pots.
