The plants grow lopsided in the pots and the stately little indoor three forms a crick in its stem. Set this right by regularly tuning the plant, remembering it will turn naturally towards the light source, although it must be said that some plants, namely Azalea, Camellia, Clivia, and Hibiscus, will not tolerate this at all. Leaf and phyllo cacti are also very sensitive when the flower buds are developing, and if these plants are turned, their buds will fall off. So let the plants stay exactly where they are and if they do start to grow crooked, support them with a stick.
Roots will rot if the compost in which they grow becomes waterlogged. Improper watering and/or bad drainage can cause stagnation. The soggy roots will then turn dark brown or even black. The plant’s new shoots droop, die off and the entire plants wilt. Severe root-rot is usually fatal but sometimes an infected plant can be saved by removing it from the pot, cleaning all soil from the roots, washing them in warm water, and then repotting the plants in fresh compost. Water very sparingly for a while, until signs of recovery to normal growth are clearly apparent.
A fungus disease that can be particularly harmful to plants during the summer which shows itself in the form of a white, powdery mould on leaves. The infection occurs if plants are placed too close together and suffer from lack of air and light, but get too much moisture. The mould can be carefully rubbed of or affected plants can be pruned back, but if the mildew is particularly persistent, the plants should be sprayed with a fungicide. When spraying, do not overlook the undersides of the leaves, but on no account allow the fungicide to touch any flowers.
Deficiency disease, better known as green sickness or chlorosis, is caused because the plant is suffering from a lack of one or more of the essential nourishing elements. The leaves take up insufficient chlorophyll and become light green, yellow, and sometimes bleached in color. Feeding needs to be correctly adjusted if the plant is to survive.
Plants standing on the windowsill need to be protected with newspaper during the night when frost is about, especially in rooms where a stove is burning. During a period of sharp frost it is best to remove all plants from the windowsill before you close the curtains, though this is not necessary if your plants are situated above a radiator. Plants standing in an unheated room should not be watered during frost period, since a wet soil-ball will freeze much sooner than a dry one. If you have to be away for a few days, the plants can be wrapped in an insulating material, such as and old blanket, corrugated cardboard or newspaper and then placed on the floor in the warmest room in the house as far as possible from the window.
How you can tell when a plant has been affected by frost?. Leaves and stem become translucent and limp, and also change color from green to dull grey. It is sometimes possible to save a plant by moving it to a dark, cool room and then spraying it thoroughly with cold water. It needs to thaw out very slowly, and if you transfer a frost-bitten plant immediately to a warm room it will have no chance of survival. If a few days after having given it a cold shower there are still no signs of improvement, repeat the process once or twice. Should the plant perk up again, you can begin to adjust it very gradually to a higher temperature.
Authors: A. C. Muller-Idzerda, Elisabeth de Lestrieux, Jonneke Krans