The dipladenia’s hardy nature and handsome, brightly coloured flowers have made it a favourite pot plant in Australian home gardens. This little beauty is versatile, too. Usually thought of as a climber, the dipladenia is just as easy to train as a small shrub. Here’s how to grow them in pots.
Dipladenias originate from the tropics and subtropics where they can flower for most of the year. They can grow well in cooler areas but will have a shorter flowering period.
Choosing a pot
The type of pot you choose for your dipladenia is a matter of personal preference. Plastic pots have the advantage of being lightweight and durable. They are also waterproof, which can slow the rate of moisture loss from the potting mix. Terracotta pots are porous which means water can be absorbed through their walls and evaporate into the air. This is especially the case with unglazed pots. However, terracotta serves as a better insulator than plastic, which can protect plant roots from extreme heat and also slow the rate of dryout.
For best results, a high quality potting mix like Searles Platinum Potting Mix is recommended as it has excellent drainage and capacity to store moisture and nutrients. It will also help insulate plant roots from heat and cold. The quality of the potting mix will also dictate how often the plants need repotting. If you are using Peat 80, you may not need to repot for some time, although a feed with Searles Recharge may be beneficial after 12 months. Quality potting mixes will have detailed planting instructions on the bag, which should be followed closely.
Dipladenias flower and perform best in full sun or part shade. In very hot areas they may benefit from light shade in the afternoon.
Left to itself, a dipladenia will grow upward to a certain height and then the long runners will tumble over the sides of the pot. Support at the base of the plant by staking it can train it into having a solid ‘trunk’ and give it a bushy or shrub-like habit. If you want your dipladenia to be a climber, provide it with a pot frame or position it near a trellis or other structure and wind the long tendrils onto it as the plant grows.
Dipladenias perform best if kept moist but should not be overwatered, so apply a generous layer of mulch. The roots are naturally adapted to store water for use in dry spells, therefore your plant won’t suffer too much if occasionally neglected. Water crystals can help keep water available in the potting mix for the plant to use as required.
The easiest method of fertilising is an application of Searles Robust in October and again in April. Alternatively, year round feeds with Searles Flourish or SeaMax Fish & Kelp — fortnightly in summer, once a month in winter — will keep the plant healthy and promote flowering.
Tip prune non-climbing plants regularly to promote bushiness. Cut back thoroughly in late winter or spring, when flowering is lightest. Even dipladenias trained as climbing plants will do best if pruned annually.
Pests & diseases
Dipladenias can be affected by soft white scale which can be easily controlled with Searles Pest Gun.
What you need to grow Dipladenias in Pots