Mandevilla are actually very easy to care for; they are rarely, if ever, infested by pests or fungi and need hardly any water.... But, if you want to enjoy the magic of your flowers until late autumn, we recommend looking a little deeper into this topic. You might also want to read about "general information on mandevilla" and on the mandevilla "varieties."
Warm, sunny to semi-shady locations are favourable, such as east or west facing walls or bright interior winter gardens. Since mandevilla can only survive outside until frost, they are most often cultivated as potted plants. This also has the advantage that the flowers are immediately higher than when planted in the ground. Unless otherwise possible, the plants can remain in their pots if there is no alternative, especially the XL types in the large "decorative pots." In general, however, eplanting into larger pots makes sense because the plant can grow larger and produce more flowers. The plants must be carefully replanted with a mixture of peat and garden soil; there should be a layer of gravel at the bottom of the plant pot for drainage. For the S and M mandevilla types, a pot capacity of 4 - 10 litres is best; for the XL types with strong growth-- a pot with 8 to 25 litres. Slim, tall pots are effective, and if at all possible, the pots should be raised so that the flowers can soon be at face level. Protect the plants from overheating by choosing lighter coloured pots (in any case, not black). It is also possible to use additional planters/cachepots as protection. If you use a cachepot/planter/saucer, be sure that no stagnant water remains after watering! Water logging means certain death for mandevilla! Read the general information page to help you choose a climbing aid for your mandevilla.
Yes, it is actually enough to water 1 - 2 times a week. The plants form storage roots, store water, and need very little of it because their leaves are covered with wax. In very hot spells, however, water the mandevilla daily. Watering more often stimulates growth!
Standing water is deadly for a mandevilla. No water should remain in pots and bowls after watering. Please remember to pour out the remaining water after watering!
The mandevilla sold by FassadenGrün are already fertilised with long-term fertiliser. Nevertheless, a liquid fertiliser can be applied every 1 - 2 weeks, especially after replanting. This may also enhance the colour of the flowers.
Actually, mandevillas do not need to be pruned. The plants "clean" themselves-- that is, the withered flowers dry out and fall off. The precious shoot growth is never shortened. If some shoots become too long, they can be wrapped/coiled downwards again around the plant and form new buds there.
Mandevilla plants are designed for one season. They are grown over many months in partly-heated greenhouses before they're sold, so that they flower in the presence of the customer when they are delivered in April / May. Of course, mandevilla can be wintered, but this is something for the most enthusiastic gardeners. In this case, they require a bright place at 10 - 15 degrees Celsius, e.g. a winter garden or an unheated staircase. Sometimes aphid (plant lice) infestation can occur here. After wintering, the plants are cut back and fertilised. The growth types S and M may have very thin, long shoots in the following year, and the flowering might start much later.