Dipladenia is a beloved tropical plant among flower gardeners, due to its trumpet-shaped flowers and branching foliage. Aside from its beauty, growing dipladenia plants attracts hummingbirds and bees to your garden, supporting nearby fruit and vegetable production.
Because it’s tropical, those in areas with cold winters have the luxury of growing a dipladenia plant indoors. Dipladenia plants can bring a burst of color to a sunny window, or they can live in hanging baskets giving growers a vibrant plant to admire even in winter light.
While dipladenia is generally a Mandevilla species, the genus encompasses plants that are called Dipladenia and those that are called Mandevilla. The two plants have distinct growing habits that deserve addressing. We will touch on that here, and discuss how you can include dipladenia flowers in your garden.
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Quick Care Guide
|Common Name||Dipladenia, rock trumpet|
|Scientific Name||Mandevilla spp.|
|Family||Apocynaceae, or dogbane|
|Height & Spread||1 to 2 feet tall, 2 feet wide|
|Soil||Loamy or sandy, well-draining|
|Water||1 inch per week|
|Pests & Diseases||Aphids, spider mites, mealy bugs, leaf spot, botrytis blight, fusarium wilt, powdery mildew and phytophthora root rot|
All About Dipladenias
Diplaenia plants are a part of the Mandevilla genus. They are also known as rock trumpet and have varying common names depending on their species and variations. The plant is native to the Southwest United States, Mexico, Central America, the West Indies, and South America. It’s a tender annual outside its hardiness zones, and a perennial inside and close to those zones.
Dipladenias are bushy plants that reach 1 to 2 feet tall and spread 2 feet wide. Dipladenia leaves are deep green, glossy, and arranged oppositely on climbing stems. While the plant does sometimes vine upward, most drape over after about 2 feet of vertical growth. In this case, the tubular flowers spill over luxuriously, attracting hummingbirds, butterflies, and bees. The flowers tend to range in color from white to yellow, pink, and orange. A few species have red flowers.
Dipladenia plants are long-blooming, opening their petals from March to November in subtropical and tropical areas. When they mature, they grow tuberous roots, making them excellent candidates for propagation by division. They are used to attract pollinators and add lively color wherever they are placed. They live happily in containers or the ground in their hardiness range. In cooler seasons, they may die back, but in the right conditions, they return in spring.
Dipladenia vs Mandevilla: What’s The Difference?
While they do exist in the same genus, mandevilla and dipladenia are different plants. We distinguish them by their growth habits. For instance, a mandevilla vine grows massively in comparison to dipladenia, vertically up to 20 feet tall. Dipladenia won’t vine more than a couple of feet before spilling over, because it’s bushier. Another distinction exists in the differences between the foliage. Dipladenia leaves are heart-shaped, and the leaves of the mandevilla vine are rough and narrow. Finally, there is also a difference in the size of the flowers of the two plants. Dipladenia flowers have smaller flowers than those of mandevillas.
Types of Dipladenias
Dipladenia sanderi is also known as Brazilian Jasmine or Rio Dipladenia. These plants grow vertically up to 15 feet tall. They are drought-tolerant plants that obtain a woody stem at maturity. The leaves are slightly glossy and similar to mandevilla leaves, and the flowers are bright red.
Mandevilla brachysiphon is commonly called Huachuca Mountain rock trumpet. This dipladenia bush is indigenous to Arizona and southwestern Mexico, displaying bushier growth in limestone soil in rocky deserts and grasslands. It’s a lovely plant to add to any subtropical or tropical garden or to plant in containers and brought indoors in winter elsewhere. The flowers are white and whirled in shape.
Mandevilla macrosiphon is called Plateau Rocktrumpet, Longtube Trumpet Flower, or Flor De San Juan. It’s a low-growing dipladenia that tops out at 1 foot. The leaves are longer than most dipladenia varieties and are covered with small hairs. Much like the Huachuca rock trumpet, the flowers are whirled and white. This dipladenia bush is native to west Texas and eastern New Mexico.
Mandevilla ‘Sunparaprero’ is a mandevilla named Sun Parasol due to its mature vine growing up to 15 feet tall. The lovely pink blooms are double the size of most mandevilla flowers, at roughly 4 inches wide. Sun Parasol is the perfect container focal point on a porch or fence. Like other mandevilla vines, it needs a trellis for support.
Mandevilla splendens ‘Fire and Ice’ is one of those mandevilla vines that sits right in the middle of the Dipladenia and Mandevilla growth pattern types. It’s technically a mandevilla because it vines vertically, but it doesn’t grow more than 4 feet tall. The leaves of the plant are variegated white and green, giving it a striking appearance. With bright red flowers, this plant is sure to punctuate any space with delightful pops of color.
Once you’ve selected the dipladenia plant you’d like to grow in your garden, you’ll need to provide conditions that can support healthy growth. Let’s cover the basics here.
Sun and Temperature
Dipladenia requires full direct sunlight in areas where it is grown in the ground – at least 6 to 8 hours of direct sunlight per day. Container-grown plants need indirect sunlight in the midday sun to ensure pots don’t dry out quickly. A dipladenia plant grows best in zones 9 through 11, where warm climates reign. Grow dipladenia outdoors in a warm location that has daytime temperatures above 70 degrees, and nighttime temperatures that are between 65 and 70 degrees Fahrenheit.
If the nighttime temperature falls below 50 degrees, cover your dipladenia plant with a protective frost blanket. In seasons where this is consistent, bring your dipladenia indoors to protect it. Frost will easily kill it. Heat and indirect or direct sunlight (depending on where it is planted) are no problem.
Water and Humidity
Dipladenia grows in dry or humid conditions and needs at least 1 inch of water per week. In early spring, let the soil dry at the top few inches between waterings. In general, keep the soil moist. In containers water more often, as the soil tends to dry out quickly there. Soaker hoses and slow, low watering methods are perfect for growing a dipladenia plant. Consistently wet soil isn’t preferred, but frequent watering in hot dry seasons is needed. Let it dry slightly between watering. Let the soil dry after rain before watering again, and don’t water too much in cooler temperatures.
Dipladenia grows well in sandy or loamy soil that drains well. Therefore, a well-drained potting mix is more than adequate. Poor soils aren’t preferable. Amend the ground with average garden soil and agricultural sand before planting dipladenia. Containers should be filled with good quality potting soil. Container-grown dipladenia will need fresh soil once per year, so repot it, transferring to a new container large enough to accommodate the plant’s root ball if necessary. Wear gloves any time you handle the plant due to its latex secretions that can irritate skin. The ideal pH for growing this lovely plant is between 6.6 and 7.8.
While fertilizer isn’t required throughout most of the growing season, fertilize the plant frequently with liquid plant food during its blooming period to help dipladenia produce more flowers. Choose a liquid plant food that has an NPK of 10-30-20, and apply the fertilizer every few weeks during flowering. As mentioned in the last section, repot the plant every growing season with new, fresh soil to supply a consistent nutrient source.
As you grow dipladenia, pinch off the top few inches of the plant slightly above the leaf node just before the blooming period to promote new growth and plentiful flowers. Then, as flowers bloom and die back, deadhead them with a pair of pruning snips to encourage even more blooms.
For Mandevilla-specific plants, ensure you delicately train it onto trellis that can incorporate a mature vine. That’s because mandevilla will not display a bushy growth habit.
You can grow Dipladenia-specific plants on a small trellis, but you’ll want to prune the ends as they begin to droop downward. While those dipladenia plants on a trellis exhibit a drooping growth habit, prune them to encourage a bushy growth habit. Simply snip above the leaf node as needed when the plant gets too tall. Time your prunings to repotting periods.
Dilpadenia plants can be easily propagated from vine cuttings, layering, or root division. Take a 4-inch cut vine, remove the bottom leaves, and dip the tip in rooting powder. Then plant the cuttings in pots, and place them in a warm area out of the full sun. They should root in three weeks or so.
To propagate by division, wait for the repotting period, wear gloves to protect your hands, and pull the entire plant gently from the container or ground. Then examine the root ball, and note where the plant sprouts from the root. Each of those points indicates where splits can occur. Have prepared pots nearby, and as you break the roots at specific growth points, plant them several inches down, and cover them with soil.
To layer propagate dipladenia, cut halfway into the stem of each of the plants you want to propagate about 9 inches from the tip. Then put a little rooting hormone on the cut, and bury the stem in the ground, affixing it with a rock. When the new plant is rooted, it can be disconnected and planted elsewhere.
While there aren’t many issues you’ll run into with dipladenia, there are a few things to pay attention to. Let’s discuss those here, and what you can do about them.
Most dipladenia problems stem from fresh air plantings that occur in the wrong zone, where nighttime temperatures dip below 50 degrees consistently. This causes damage to foliage and trumpet-shaped flowers. Instead, keep these plants in containers so they can be overwintered indoors. Move them indoors when temperatures drop below 68 degrees in the daytime. Find a full sun location in your home to help them survive the late winter cold.
If you grow indoors without enough sunlight dipladenia may experience stunted growth and a lack of blooms. Either move the plant to a brighter location or provide a timed grow light to ensure enough sunlight gets to your plant.
If you grow your dipladenia plant in poor soil, it may not develop the blooms you selected it for. To promote flowering establish a place that is rich with organic matter, and apply fertilizers every couple of weeks in the blooming period, from spring to fall. Dipladenia can be scorched by too much organic matter. Ensure the amount of rich soil is balanced by sandiness that promotes drainage.
Aphids that feed on Mandevilla species are small and either black or yellow. They suck sap from the vines and leaves of the plant and weaken its ability to produce bright blooms. They cause yellowing leaves and leaf curl in late-stage infestations. To rip their suckers from their pear-shaped bodies, spray the plant with a strong stream of water from a sink faucet or garden hose, depending on the weather. Apply insecticidal soap or neem oil sprays every 7 to 10 days to stop them. Neem oil should never be sprayed during flowering as it will deter pollinating insects.
Spider mites are tiny, sugar-grain-sized bugs that feed on the sap of leaves and vines of your plant. They will spin webs around the plants in late stages as well, depriving the plant of nutrients and causing defoliation. More typical in dry, hot seasons, they tend to infest plants that have been watered improperly from above rather than at the root level. To rid them from your plant, use a cloth with rubbing alcohol to remove them from the plant. Sprinkle diatomaceous earth on the soil around your plants, and follow up with insecticidal soap sprays every 7 to 10 days until the problem ceases.
Mealybugs are fuzzy white bugs that look like small cotton balls and also feed on the sap of vines and leaves. And they too cause yellowing leaves and defoliation. Spray plants (even those indoors) with insecticidal soap every 7 to 10 days, after wiping the bugs off the plant with an alcohol-soaked cloth. Allow some time between the two so as not to burn the leaves.
Anthracnose leaf spot is one of the fungal diseases that dipladenia develops in wet and warm conditions. It starts as a yellow or brownish spot, and slowly grows or develops more spots. Slightly glossy leaves can turn yellow and drop from the plant, reducing blooms and weakening it overall. Prune diseased leaves as soon as possible to control the spread of the disease. Drench your dipladenia with a mist of fungicide spray and reapply once every 7 to 10 days until the problem ceases.
Botrytis blight is caused by water mold that thrives in cool temperatures when high humidity or precipitation exists. It causes wilting foliage and the development of brown tissue on leaves. The vines are covered in gray mold in the late stages of the blight. As signs first develop, apply copper fungicide sprays all over the plant. Then reapply every 7 to 10 days to stop the infection. Prevent the mold by watering at the base of your dipladenia.
Fusarium wilt, another one of those fungal diseases that affect dipladenia, is caused by the pathogen Fusarium oxysporum which proliferates in warm and wet conditions. It causes wilting foliage on select sections of the plant. Unless you catch it in the early stages and apply a broad spectrum fertilizer to the entire plant, you may have to remove your dipladenia and dispose of it. Later stage infections are not treatable.
Powdery mildew causes white, powdery spots on the leaves of your dipladenia vine. The spores of the fungus that causes the disease spread via the wind in humid weather. Proper pruning to provide air circulation to parts of the plant helps prevent the disease. Placing plants in adequate sunlight helps too. Otherwise, horticultural oil applied outside the flowering stage can lessen an infection.
Phytophthora root rot is a water mold disease that causes rot on the roots of dipladenia. It occurs in Mandevilla species that are overwatered. Signs of root rot are browned and mushy vine bases. Attempt to recover your plant by uprooting it, and repotting it in new, better draining soil. Otherwise, it must be removed and destroyed to prevent the spread of the disease.
Frequently Asked Questions
Q: Is Dipladenia an annual or perennial?
A: It’s technically perennial in its zones, but annual outside them.
Q: Do Dipladenia come back every year?
A: In their USDA hardiness zones, they do!
Q: Does a Dipladenia need a trellis?
A: Since dipladenia has bushier tendencies, it doesn’t need a trellis, though you can train it onto a small 2-foot trellis for it to spill over. That tendency to drape over also makes these excellent candidates for growing in raised beds or containers.
Q: How long does Dipladenia last?
A: It will last year-round if it’s not exposed to frost.
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