Dipladenia plants are a sight to behold with their lush foliage and bright blooming flowers. These popular ornamentals are perfect for landscape, balconies, and patio designs and attract hummingbirds, butterflies, and bees.
While they are relatively easy to care for, there are some key growth and care tips you’ll need to know to keep your Dipladenia happy, lush, and blooming all summer long.
Quick Dipladenia Plant Overview
Dipladenia, also known as Mandevilla or rock trumpet, is a tropical flowering perennial shrub native to Central and South America. It’s a member of the Apocynaceae family and is a sub-species of the Mandevilla vine.
Rocktrumpet has become popular as an ornamental annual or perennial house plant due to its dark glossy leaves and beautiful, voluptuous trumpet-shaped flowers.
Because of its increasing popularity, several cultivars and hybrids are available, creating variety in the plant’s growth structure, leaf and flower size, and flower color. Dipladenia’s flower color ranges from dark red to peachy pink to creamy white, depending on the cultivar.
As a native of humid and warm climates, Dipladenia can grow in zones 9-11. In hotter regions, it can be grown as an in-ground perennial.
It can be grown as an in-ground annual or potted plant in cooler climates. To grow it as a perennial in cold climates, it’s recommended to “overwinter” your Dipladenia, which I’ll describe in more detail below.
Dipladenia Plant Care & Growing Guide
Lighting Requirements: Dipladenia Sun or Shade
Dipladenia thrives with exposure to direct sunlight and prefers full sun to part shade. In hot areas, it may benefit from some afternoon shade.
There is variance in people’s experience of what their Dipladenia prefers – some say that the afternoon sun during the summer months started to scorch their plants, while others claim it thrived in full sun with no problem.
Use your best judgment with your Dipladenia plant, and if hours of direct sunlight seem to be getting to it in the afternoon, provide it with some shade.
If growing a Dipladenia bush as a houseplant, give it bright, indirect light.
Place it near a south-facing window, but limit its exposure to direct sunlight streaming through the windows. This can scorch your plant if exposed for too long. Better yet, find a place indoors where it will receive direct morning sun and indirect light in the afternoon.
Watering Needs
Diplandenia’s watering preferences depend on the time of year and whether it’s growing in a pot or in the ground. Generally, it prefers somewhat consistent moisture and well-drained soil during the growing season.
It does not like to be overly moist or water-logged – if exposed to too much water, it’s prone to root rot. Because it has starchy, thick roots once established, it’s quite drought tolerant and can go through periods of dryness.
If your Dipladenia is in the ground, water it only once the top 2 to 4 inches of soil has dried out. You will probably have to water more if your Dipladenia is in a pot; check it consistently and water once the top few inches of soil are dry.
When overwintering your Dipladenia indoors, you will only have to water once a month or so as the plant will be dormant.
Fertilization Needs
Dipladenia’s aren’t nutrient hungry, nor any special nutrient requirements. It’s best to provide a general-purpose, slow-release fertilizer at the beginning of the growing season or when the plant starts to flush out and repeat, if necessary, around mid-summer. You can use a pellet fertilizer or liquid plant food.
Don’t fertilize too much, as over-fertilizing and too much nitrogen can cause leaf discoloration and inhibit flowering.
Pruning Dipladenia Plants
Dipladenias can be pruned whenever needed – make sure to leave enough foliage near the base of the plant to help it flush out again. It’s best to snip wayward and leggy stems right above the leaf node so it’s easy for the plant to regrow.
It might be best to prune your Dipladenia in the spring before it fully flushes out. Either way, you’ll want to cut back the foliage in the fall before you bring it in to overwinter.
When pruning your Dipladenia plant, you’ll notice a milky white sap excreting from the snipped stems. This substance is considered toxic, so avoid touching it with bare skin. It’s advised to wash your hands directly after pruning or to wear gloves.
Along with pruning, frequent deadheading of old Dipladenia flowers on your plant will promote new blooms.
Repotting Dipladenia
Dipladenias don’t need repotting often, as they don’t mind being mildly root-bound. However, once you notice the water running straight through or roots poking out the bottom of the pot, it’s probably time to repot your Dipladenia plant.
If your Dipladenia is root bound, don’t break up the roots too much, as they are sensitive to root disturbance.
Be very gentle; it’s best to maintain whatever root shape there is – simply transfer it to a new pot with a couple of inches on the outside diameter. Then, fill the outside diameter with your potting mixture.
You can use a multipurpose potting mix as your medium; they don’t need anything special since they’re not super nutrient hungry. Consider mixing a little perlite, sand, and/or grit into your potting mixture to support water drainage and prevent overly moist soil.
Pests & Diseases
Dipladenia isn’t prone to pests or diseases, but it may be affected by common pests such as aphids, white flies, scale insects, mealy bugs, and spider mites.
Insecticide soap should clear up the problem. It can also be affected by common fungal diseases if fungal pathogens are widespread in your area, such as powdery mildew.
How to Propagate Dipladenia Plants
Dipladenia can be successfully propagated through cuttings or layering, though it’s more common to propagate Dipladenia through cuttings.
Propagating Dipladenia
To make a cutting, snip back a healthy, sturdy stem about 5 to 6 inches long. Cut it right below a node where it contains its natural rooting hormones.
Strip back the bottom leaves, leaving a few leaves at the top to promote root growth. You can then dip the stem into a rooting hormone, though this isn’t necessary for your cutting to be successful.
Then, place your Dipladenia cutting a few inches down into a moist potting medium, put a plastic bag over the cutting, and prop up the bag with a stick so the bag doesn’t touch the plant. This creates a warm and humid environment for the cutting.
Keep your Dipladenia cutting out of direct light, keep it warm, and in a few weeks, it should take root.
Winter Care: How to Overwinter Dipladenia
In colder climates (zones 8 and under), it’s best to bring your potted Dipladenia indoors before the first frost. If your plant gets hit with a frost, it may not survive as they are incredibly cold-sensitive.
Dipladenias and Mandevillas have a natural dormant period from October to April. It’s normal for them to cease growing and drop their leaves during dormancy.
Because of this natural period, you can overwinter your Dipladenia by cutting it back in the fall (leaving a few inches of growth at the base), then sitting it in your garage (if your garage stays above 45 degrees Fahrenheit) or in cold storage in a basement.
If you don’t have a warm garage or cold storage, you can bring it into your home and keep it out of direct light.
Only water a little during this time, as it doesn’t need much water during its dormancy. You don’t want the potting medium overly moist, or the roots may rot – just make sure the soil doesn’t completely dry out.
At the very beginning of spring (March or early April), place your Dipladenia in a warm, well-lit room near a window to promote spring growth.
Be patient; it may take a while for new growth to emerge. Don’t set your Dipladenia outdoors until night-time temperatures reach around 50-60 degrees Fahrenheit.
Alternatively, if you have an inground Dipladenia, live in a warmer climate (8b and above), and don’t have hard frosts, you can overwinter your Dipladenia by providing about a foot of mulch around the stem.
Pull the mulch away once temperatures start warming up in the spring, and it should return. If you have a potted Dipladenia in a warmer climate, you can bring it indoors on cooler nights and then set it back outside during the day’s warmth.
In even warmer climates (zone 9-11), overwintering your Dipladenia probably isn’t necessary, though it may still go through a dormancy period where its leaves will yellow and drop.
All that said, if you have a heated and humid greenhouse, you can successfully grow Dipladenia as an evergreen perennial that blooms all year long.
Dipladenia vs Mandevilla: What’s the Difference?
Dipladenia’s are often referred to as Mandevilla’s, and vice versa. What makes things even more confusing is that garden nurseries often display these tropical plants as the other. However, there is, in fact, a difference between the two despite being closely related.
As mentioned, Dipladenias are a subspecies of the Mandevilla vine (Mandevilla spp.), and the most significant difference lies in their growth pattern – Dipladenias grow as shrubs, while Mandevillas grow as vines.
Because of this, your Dipladenia does not need a trellis or anything to climb on, as it is not an upright climbing variety like the Mandevilla vine. It may produce vine-like tendrils – these can be pruned to help the plant bush out and form a fuller shape.
Alternatively, you can try to stake it or put it against a trellis, but it won’t vine like a mandevilla.
Furthermore, Diplandenias often produce smaller flowers than Mandevillas ¹. Dipladenia’s are frequently sold as hanging basket flowering plants, while Mandevillas are typically staked to a trellis in the pot they’re sold in.
That said, both Dipladenia and Mandevilla require the same growing care to produce vibrant and consistent blooms.
Dipladenia Plant: The Perfect Ornemantel for Long-Lasting Summer Blooms
Dipladenia’s are truly stunning with their bright and everlasting blooms. With these magnificent flowers, you can add a splash of color to your garden, patio, balcony, or landscape design.
By meeting their preferred watering, sunlight, and nutrient needs, you can have a vibrant and happy Dipladenia that blooms all summer!
FAQs
Is dipladenia an annual or perennial?
Dipladenia is a perennial flowering vine in tropical and subtropical regions. It’s treated as an annual or overwintered indoors in colder climates, as it’s not frost-tolerant. Its vibrant, trumpet-shaped flowers bloom from spring until the first frost.
Are dipladenia poisonous to dogs?
Yes, Dipladenia plants are toxic to dogs. They contain compounds called cardiac glycosides ², which can cause symptoms like vomiting, diarrhea, and even heart abnormalities if ingested by pets. If your dog ingests Dipladenia, seek veterinary help immediately.
Do deer eat dipladenia?
While deer are known to eat a wide variety of plants, Dipladenia is not typically a preferred choice due to its toxicity. However, in situations of scarcity, deer may still nibble on them. It’s advisable to use deer-resistant plants or deterrents to protect your garden.
References
1: extension.msstate.edu/news/southern-gardening/2022/mandevilla-and-dipladenia-although-similar-flowers-one-vine-other-shrub
2: petpoisonhelpline.com/poison/cardiac-glycosides/
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As an herbalist, my goal is to connect people with the healing powers of nature. Through my writings and herbal concoctions, I aim to guide others toward a healthier lifestyle using time-honored methods. With over four years of experience studying herbalism and organic gardening, I offer my knowledge to inspire others to explore the natural world, cultivate their own gardens, and rediscover their bond with the earth.