Dipladenia, commonly known as the Rock Trumpet, is a tropical, flowering plant that belongs to the Mandevilla family.
Dipladenia produce beautiful trumpet-shaped flowers in a range of colors, including pink, white, and yellow, adding a vibrant touch to the garden, patio or courtyard.
Dipladenia or Mandevilla?
When asked about the difference between these two related plants, the answer is fairly simple.
While it shares many characteristics with Mandevillas, Dipladenia is distinguished by its more compact, or lax growth habit. Mandevillas are vigorous climbers. Dipladenia are more a bushy.
Often considered a variety of Mandevilla sanderii, wih its more restrained, bush like form, making it an excellent choice for smaller gardens or container gardening.
- Smaller flowers
- Narrower pointier Leaves than the broader leaves of Mandevila.
- Bushier growth habit
Being a sub species of Mandevilla sanderii rather than its own species this leads to a little confusion with with names.
All Dipladenias are actually Mandevilla sanderii cultivars, Dipladenia is the common name, but it sounds like a botanical name. And to further confuse, some white Diplandenias are Mandevilla boliviensis cultivars.
So Dipladenia is another name for a compact form variety of Mandevilla sanderi.
Foliage also differs a little, the leaves are narrower and more lancelot in shape.
This is where the difference ends. Care is virtually the same.
How to grow Dipladenia – Basic Care
In warmer climates Dipladenia will flower almost year found, they make great plants for containers. In cooler areas they will have flowering limited to summer, and will need protection from frosts over winter.
Although these are plant that like warmth, they do not like direct hot afternoon sun, so filtered afternoon light in a warm position is best.
These are a plant that like warmth, they also like moisture. They flower well in bright light, however you will find that very bright filtered light is best.
Moisture needs to be controlled, Dipladenia do not like wet soggy soils, overwatering can kill them. Lack of moisture is also a problem.
- Light:
Dipladenia thrives in bright, filtered light. While it enjoys warmth, it does not tolerate direct afternoon sun, which can scorch its leaves. A warm, sheltered position with some shade during the hottest part of the day is ideal. - Soil:
Dipladenia prefers well draining, humus rich soil. If growing in containers, use a good quality potting mix with added compost to ensure the plant receives the nutrients it needs. Mulching around the plant helps maintain a cool root environment. - Watering:
This plant requires consistent moisture but dislikes soggy conditions. Overwatering can be harmful, so ensure that the soil is kept moist but not waterlogged. Water when the top of the soil begins to dry out, and be sure to allow the container to drain freely. - Temperature:
Dipladenia is sensitive to cold temperatures and should be kept in a frost free environment. In cooler climates, it should be brought indoors or placed in a sheltered position during the winter months. It thrives in temperatures above 8°C (46°F) and can be grown year round in warmer climates. - Fertilizing:
Dipladenia is a hungry plant and benefits from regular feeding during the growing season. Use a liquid fertilizer every 2–3 weeks when the plant is actively growing. In spring and early summer, consider applying a slow release fertilizer to promote healthy growth. - Support:
Due to its bushy growth habit, Dipladenia benefits from being staked or supported, especially if you want it to grow upright. While it won’t climb as aggressively as Mandevilla, it can still benefit from some structural support.
Top Tips
- Growing in containers is a good option, if you choose the right one. It needs to be big enough to enable the root system to remain cool. Use a good quality potting mix with some well rotted compost mixed in.
- Mulch around the plants to maintain that cool root run.
- As mentioned Dipladenia has a rather lax growth habit, it will benefit from being staked and supported, it can them be allowed to cascade back down.’
- These are also a hungry plant, they do like a humus rich fertile soil. A liquid fertiliser every 2 – 3 weeks when in active growth is usually sufficient.
Overwintering
In colder climates if you want your Dipladenia to survive, you will need to overwinter the plant indoors or if you have one, in a greenhouse and do not fertilise during winter. Cut back on watering, keep the soil just moist.
Although this is a perennial plant in colder zones it is often treated as an annual.
- They do like a warm sunny position and can reach 3m+ in good conditions.
- Flowers are usually a brilliant pink such as ‘Red Riding Hood’, or white. Yellow flowers are also available.
- A well draining potting mix is essential and protection from frosts is need in cooler areas.
- These wonderful flowering plants grow well from SE Queensland to further north. They will grow as far south as Melbourne in protected warm positions.
- As we move south, consider a warm sheltered position, or grow as a patio plant.
Pruning Dipladenia
To maintain a tidy shape and promote healthy growth, regularly tip prune Dipladenia during its active growing season.
Prune back harder in the winter months to encourage a fresh, compact structure. If the plant becomes leggy or overly long, cut back the stems to encourage new growth and flowering.
Problems
Yellowing Leaves: Yellowing leaves and leaf drop are typically signs of stress, often caused by cold temperatures or overwatering. Ensure the plant is in a warm location and that the soil is not too soggy.
Overwatering causes root rot can also be recognised by some wilting. Stop watering OR better still prune the plant back and repot your plant into a new potting mix.
Named Dipladenia Varieties
- Dipladenia Marbella ‘Hot Pink’ – Lipstick Pink flowers on a compact plant.
- Dipladenia ‘My Fair Lady’ – White flowers tinged with pink, long flowering and excellent for hanging baskets.
- Dipladenia ‘Scarlet Pimpernel’ – Mid to deep red flower.
- Dipladenia ‘Rio White’ – Good clean white flowers.
Summary
Also known as the Brazilian Jasmine, a climbing plant, however with a bushy habit that makes it a versatile garden plant. With brilliant trumpet shaped flowers well suited to growing in a pot or container as long as you can provide a climbing frame for it.
The main difference is that these wonderful plants do not have the same vigorous climbing habit as Mandevilla. This makes then well suited to growing in containers as well as in the garden where they can be pruned to a rounded shrub.
Container growing is well suited to cooler climates so that plants can be moved to a protected position over winter if needed.
- Best in full sun.
- Humus rich moist soil or potting mix.
- Keep at above 8C and frost free at all times.
- Water during active growth as soon as the soil at the top of the pot begins to dry.
- Fertilise avery 3 weeks with a liquid fertiliser. Use a slow release fertiliser in spring and again early summer.
- Prune as needed to maintain shape and size.
With proper care, Dipladenia will reward you with months of colorful blooms, making it a standout in any garden or container display.
