How to Grow Houseplants Successfully
Growing plants is not particularly easy, a fact that both beginners and experienced growers will confirm — even specialists, when they remember the time they waited in tense anticipation for a plant to bloom. The most important trait for every lover of house plants is patience. This is particularly true in the case of uncommon species that do not have a rapid rate of growth. Often it is necessary to try out several different places in the home before finding the spot that suits the plant best.
Finding the best growing compost, how much and how often to feed and water, all this is a question of trial and error that sometimes requires starting anew. Perhaps it is for this very reason that growing plants is such a popular pastime. A person can give his imagination free rein. Experiments often bring surprising results and the reward is a blossoming plant in all its glory. Mention has already been made of light requirements and 21 the fact that plants are divided into light-lovers and those that tolerate shade. Growth is promoted chiefly by the red to infra-red range of the spectrum; violet and ultraviolet rays tend to retard growth. If plants are grown in plant-cases with artificial illumination it is recommended to use fluorescent lamps with violet-red light or a combination of these and white fluorescent lamps.
As for temperature requirements, we already know that it is necessary to find out as much as possible about the origin of each species and adapt the temperature according to its native habitat. In many caseswill not develop unless the plant is exposed to low temperatures for a period.
This is true of bulbs and tubers, which generally ‘die back’ and pass the cold period in a dormant state, as well as plants with storage tissue in woody stems, for example brunfelsia, bougainvillea and erythrina. Orchid growers are well acquainted with the requirement of the popular cymbidiums which must be exposed to low temperatures in autumn in order to form flowers. The temperature fluctuations required by the type species, however, need not be observed in the case of many cultivated forms, which can be grown at an even, usually higher temperature.
Water should also be applied according to the climatic conditions of the plant’s native habitat, though naturally with an eye to the temperature and amount of light in the home. Soft rainwater is the most suitable and should be used whenever it is readily available. However, in places where the atmosphere contains a large concentration of dust and ashes, for example near industrial conurbations, rainwater may contain many harmful substances which have a toxic effect on plants and should thus be avoided. Only species from dry regions tolerate constant watering with hard water, that is water containing calcium and magnesium salts, without suffering any damage. Such water is also unsuitable for plants that grow in acid forest humus or peat moors. House plants, however, generally tolerate water from the tap. If possible, it should be left standing overnight to allow for the evaporation of the chlorine, which is toxic to plants. The temperature of the water should be the same as that of the room or, preferably, 2 to 3°C (4 to 6°F) higher. Particularly damaging to plants is syringing with exceedingly cold water. In the case of plants with leaves that are felted or covered with long hairs, syringing should be avoided altogether.
Last on the list, but just as important, is themixture. Preparing it can be quite an art. Old gardening books contain instructions for dozens of mixtures and the required portions either by volume or weight. In an effort to standardize and simplify matters, the John Innes potting composts were introduced. These consist basically of loam, peat and sand mixed in the proportion of 7 parts by bulk of loam, 3 parts of peat and 2 of sand. To this mixture John Innes Base Fertilizer is added in varying quantities to give three different strengths of compost: John Innes potting compost No. 1 for slow-growing plants in small pots; No. 2 for medium-sized plants; and No. 3 for vigorous plants in large containers. More recently, soilless composts have become very popular. These may be composed entirely of peat with the addition of fertilizer, or a mixture of peat and sand or peat and vermiculite, again with added fertilizer. Soilless composts are readily available at garden centres and nurseries, as are the John Innes potting composts.
Every plant will at some time fill its pot with roots, leaving no room for further growth. In extreme cases roots will suddenly begin to appear on the soil surface or the pot may even crack. The experienced grower naturally takes care that this does not happen and in the spring of each year he moves rapidly-growing plants to larger pots (older plants every 2 or 3 years). The beginner’s chief mistake when re-potting is to select a pot that is too large, with the well-meant intention of providing the plant with plenty of space and nutrients. In such a case the plant is never able to fill the pot with its roots and most of the compost is unused.
When transplanting a plant, choose a pot that is only slightly larger than the one used before. Loosen the plant by tapping the pot, tip it out and remove old soil clinging to the roots with a blunt wooden stick. Before putting the plant in the new pot cover thehole with crocks and top them with a layer of new compost. Then put the plant in, add the fresh compost, and firm it down around the root ball. Do not fill the pot up to the rim; leave room for watering.
The new compost will contain ample nutrients so it is unnecessary to apply feed for the first month or two (doing so might even damage the plants). After this time, of course, feed should be applied regularly throughout the growing period. In the autumn, before the onset of the dormant period, feeding should be reduced and then stopped altogether. There are plenty of proprietary feeds on the market and these can be purchased at a nursery, where you will generally be advised as to which kind is best for a given plant and in what concentration. Remember, also, to follow the manufacturer’s instructions. Plants with ornamental flowers need fertilizer with ample phosphorus. Nitrogen promotes plant growth, but care must be taken when applying nitrogenous fertilizers to plants with variegated leaves for these turn green if given too much nitrogen.