Dipladenia, also known as Mandevilla, is truly continuous bloomer among container plants. The exotic climbing plant adds greenery to screens, trellises and balcony railings.
Dipladenia (Mandevilla) are climbing shrubs from the dogbane family (Apocynaceae). They originate from the jungles of South America and have been a widely popular pot and container plant for over 100 years. The wonderful white, pink, red and yellow colored flowers of the evergreen climbing plant decorate balconies and terraces for almost the entire summer. The plant is generally called Mandeville (named after Henry John Mandeville) today, and is also frequently referred to under its old botanical name, ‘Dipladenia’. Over 120 species of Dipladenia are known. The most widely cultivated plants are the hybrids from the wild flower species Mandevilla sanderi, which are kept small, and which were crossed with other species such as Mandevilla spendens or Mandevilla boliviensis. A special outdoor type is Mandevilla laxa, also known as Chile Jasmin, which has white flowers and a greater tolerance to cooler temperatures.
Appearance and Growth
The evergreen Dipladenia are fast-growing climbing shrubs which wind rapidly upwards, provided they have sufficient nutrition. Depending on the variety, the liana-like climber can reach up to 19.7 feet. Compact breeds for balconies and window ledges are often found commercially. An artificial containment of the growth drive keeps them small and compact - albeit often only for the first year. After overwintering in the second year at the latest, when this containment agent has lost its effect, they shoot up noticeably.
The dark green, shiny leaves of the Dipladenia sit on short stalks and are slightly hairy. The leaves contain unnoticeable glands. Damaged leaves and stems leak a white latex. This tastes bitter and is slightly poisonous. The five sepals of the Mandevilla open into 0.39 to 1.97 inch funnel shaped flowers in the colors white, yellow, violet and various tones of red. Dipladenia flower from May until autumn and form new buds over and over throughout the entire summer. The breeds here show a stately abundance of flowers. The white flowers of the winter green Mandevilla laxa also give off a pleasant fragrance. Pollination mainly occurs through bees and bumblebees, and also through hummingbirds in their tropical home.
After flowering, capsules appear on the plant with long, hairy seeds inside. For more flowering abundance, you should remove mature fruit, this saves the plant unnecessary energy consumption.
Location and Substrate
The various Dipladenia species are suitable both for balconies and terraces, as well as warm conservatories. Mandevilla laxa can also be kept in cold conservatories. For rich flowering, the frost-sensitive beauties always require plenty of light. Place plants in an extremely light, humid position, ideally where they are protected against the strong afternoon sun, as Dipladenia react sensitively to this. However, Mandevilla do not mind the heat.
Mandevilla also thrive in sufficiently warm, semi-shade, although then the flowers are somewhat sparser. Temperatures of 68 degrees Fahrenheit and more are perfect. Dipladenia are best planted in high-quality plant pot soil, whereby they also tolerate slightly acidic, alkaline or calcareous soil.
They only require moderate watering. The plant can hold water stores for long periods in its thick leaves and reservoir roots. Always water the climbing plant in such a way that the root ball is thoroughly moistened but not wet. Take care to ensure excess water can drain straight off, so as to prevent waterlogging. Only use temperate, if possible lime deficient, irrigation water. Keep the root ball evenly moist during the entire growth period and spray the plant more frequently. Reduce the amount of watering after flowering. For climbing plants to thrive, they should be fed once a week with a high-quality liquid fertilizer. As Mandevilla are climbing plants, they need a climbing aid in plant pots. Repeatedly guide the winding shoots through the climbing aid before they get caught up in neighboring plants.
The plant needs re-potting into a slightly larger plant pot every two to three years in the spring, when the root ball is completely rooted. Larger Dipladenia cope well if the root ball is simply made a little smaller and replaced back in the same plant pot with fresh soil. When re-potting, you should add some long-term fertilizer to the substrate.
You can lightly prune the plant all year round. However, the Mandevilla flowers on new shoots, so it should no longer be pruned too heavily later in the season. Plants which have become to large and unshapely and require heavy cutting back, are best pruned in late winter (February/March). During this period, pruning stimulates new shoots and therefore flower formation. Dipladenia aren’t even averse to pruning near to the soil - in the spring the plants will reshoot again vigorously. Young plants should be pinched regularly for bushier growth. The shoots should then be dipped in water or sprayed with water i order to stop heavy latex flow.
The exotic plants, with the exception of the Mandevilla laxa, are extremely sensitive to the cold. For this reason, they should be placed in a light, 41 to 53.6 degrees Fahrenheit winter residence before the first frost. If the plant is overwintered somewhere cool, the Dipladenia will enter a resting phase between October and March. In this case, the plant should be watered less so that the root ball can dry out in between. If the plant is kept indoors or in a heated conservatory at over 68 degrees Fahrenheit, it can be cared for as usual and will then also continue to flower in the winter. However, the lack of a rest phase can have a negative effect on the abundance of flowers.
In contrast to many other species, the Chile Jasmin (Mandevilla laxa) tolerates a brief period of frost as low as 23 degrees Fahrenheit. Nonetheless, it should only be overwintered outside in very mild places with good frost protection. Ensure there is sufficient air humidity in the winter location and ventilate on frost-free days. Container plants can be taken outside again in May after the last late frosts.
Propagating Mandevilla at home is a matter of pure luck, as the rooting rate is not very high. However, if you still want to give it a go, you can cut a roughly 3.94 inch long head cutting from the shoot tips, remove all but a few leaves, dip into some rooting powder and then push into a soil-sand mixture or planting soil. The plant pots are watered, covered with a transparent film bag and not reopened for the time being. Alternatively, a securely closing mini-greenhouse can be used. In warmth (significantly above 68 degrees Fahrenheit) and plenty of light, for example on a window ledge above a radiator, the cuttings will form their first new shoots after a few weeks.
It is only a question of patience: The plastic cover should be ventilated daily over a several months until it shows several young shoots. If the small plant grows back vigorously, it can be moved to a larger plant pot without a cover. In early summer, Dipladenia can also be propagated through layering. This requires a long, slightly woody shoot, free of leaves in the middle section with its bark slightly scratched. The shoot section prepared in this way is pushed into the soil next to the mother plant. Tip: The offset can be perfectly anchored into the soil with a hairpin. The shoot tip at the other end should poke out of the soil. Here, too, successful rooting is visible in strong, new shoots.
Species and Varieties
The Mandevilla sanderi hybrids ‘Sundaville’ and ‘Tropidenia’ are particularly resistant to dry weather. Several compact varieties from the ‘Jade’ series perform wonderfully in window containers. Climbing species such as the White Dipladenia (Mandevilla boliviensis) are perfect for covering trellises in tendrils and extremely suitable as a privacy screen. Small-growing varieties, such as the ‘Diamantina Jade White’ are ideal for hanging baskets. The pink colored Mandevilla x amabilis ‘Alice du Pont' with up to 3.94 inch large funnel flowers is considered the Dipladenia with the largest flowers. It is strong-growing and forms feet long shoots which can be guided along a climbing frame. The Mandevilla hybrid ‘Sundaville Red’ is at home in the heat and tolerates dryness, it is adorned throughout the summer with velvety red flowers. When guided on a climbing frame it can reach around 60 inches tall.
Diseases and Pests
Dipladenia are particularly stress-resistant. They are particularly susceptible to pests such as White fly, when there is long-lasting heat and dryness. Adhesive straps can be provisionally positioned around the plant, however for extreme infestation a pesticide must be used. Aphids often appear on the leaves at the start of May. If the air is too dry, this can result in rolled up leaves. During the winter months, Dipladenia are often infested with Mealy bugs. Where there is an extreme case of infestation, the plants should simply be radically pruned back in late winter.
Frequently Asked Questions
When are Dipladenia available to buy?
As Dipladenia are often sold in flower, they are commercially available from May.
What colors of Dipladenia are available?
Dipladenia are available in different shades of red. However, yellow, white and violet specimens are also available.
How tall do Dipladenia grow?
Depending on the variety, Dipladaniea can grow up to 20 feet tall.
How often should Dipladenia be watered?
During the growth period and on warm days in particular, Dipladenia should be watered so that the root ball always remains moist. However, waterlogging should be avoided. Reduce the amount of watering after flowering.
What kind of soil does the Dipledenia require?
You should use a high-quality soil to ensure that the Dipladenia feel completely at home. However, they also manage in calcareous, alkaline or slightly acidic soil.
What stops Dipladenia from flowering?
There can be different reasons why a Dipladenia doesn’t flower: Both the wrong location as well as incorrect watering can lead to a lack of flowers.
How should I care for my Dipladenia?
Dipladenia should be regularly watered and fertilized once a week. As it is a climbing plant, Dipladenia requires a climbing aid. If the plant pot is completely filled with roots, it can be re-potted. This is the case every two to three years.
How much cold can the Dipladenia tolerate?
Apart from the Mandevilla laxa breed, which can even survive in temperatures as low as 23 degrees Fahrenheit, unfortunately Dipladenia cannot withstand the cold. If temperatures fall below 46.4 degrees Fahrenheit, the tropical plants quickly freeze.
How should I overwinter Dipladenia?
A Dipladenia can be overwintered at a cool 41 to 53.6 degrees Fahrenheit as well as inside at over 68 degrees Fahrenheit. The location for overwintering a Dipladenia should be light in both cases. If the plant is kept cool, it enters a rest phase. If it is kept warm in the winter it will flower again.
When can I take the Dipladenia outdoors again?
Sensitive plants such as the Dipladenia may only be taken outside again after the frosts have finished.