Monthly Calendar March
Now is the time to repot your houseplants; the roots are often to be seen growing through the drainage hole under the pot, and this means that the plant needs a little more living room. The Clivia generally needs repotting every two or three years; use this opportunity carefully to remove the young shoots, which some attached roots. These can be planted in a separate pot. The Bellflower (Campanula Isophylla) is grateful for some fresh compost around this time, and will also respond well to a sunny spot in a heated room.
The flowering Slipper Flower (Calceolaria) should be given a cool location. The same treatment applies to the Senecio (Cineraria); both species need plenty of water and a fortnightly feed with a nutrient solution. When the Amaryllis (Hippeastrum) has finished flowering, it should be treated as follows: cut the flower stem back as far as possible and give the plant water and fertiliser right through the summer. This also applies to the Veltheimia when it has ceased flowering.
The Begonia that will no longer flower should be cut back to a few centimeters above the soil surface. The summer-flowering Vallota has a bulb, which can now be potted up (a third of the bulb should be visible above the soil), then give the pot a position in front of a sunny window in a warm room.
Not too much water. If the plant has overwintered successfully you need only renew the top layer of compost. This also applies to the Haemanthus, species of which are commonly known as the Blood Lily and Fireball. The Haemanthus prefers to remain in the same container and should not be repotted unless this is obviously necessary. Cuttings of Busy Lizzie (Impatients), Gynura, Pilea, the Flame Nettle(Coleus) and the Rheumatism Plant (Plectranthus Fruticosus) can be encouraged to form healthy roots if placed in a glass or bottle of water in a warm environment. The cuttings of Ficus, Begonia, Aphelandra, the green and variegated climbers (Hedera), Iresine and Oleander (Nerium) root well with this simple method. With the exception of the Aphelandra, they are best given a location in front of a sunny window.
When taking cuttings, cut straight across with a sharp knife just below a leaf joint – the thickened part of the stem from which the new shoots and leaves emerge. Cuttings can also be rooted directly into compost, and with species that show poor progress, it is recommended to help them along with a little hormone powder, which encourages rooting. Various brands are sold at most garden shops. You first dip the end of the cutting in water, then into the powder and finally place it carefully into the cutting compost. Covering with a polythene bag and providing soil warmth will stimulate the root development of most houseplants.
Authors: A. C. Muller-Idzerda, Elisabeth de Lestrieux, Jonneke Krans