Grouping houseplants for great effect in interior design

Besides being more appealing to the eye, plants that are grown together in a group will almost invariably be much more satisfactory in respect of growth.

All sorts of containers may be used for this purpose, from the very cheap plastic one hold­ing a few small plants to the more ambitious affair where plants may be grown to quite majestic proportions. The smaller container is the sort of thing that you receive as a gift and enjoy for 12 months or so, by which time the plants will either have died off, or they will have begun to outgrow the container. Plants dying off is usually the result o( too much water. The roots rot and die, soon to be fol­lowed by leaves turning yellow and falling off. When plants become overgrown in smaller containers the obvious remedy is to remove them from the pot and to plant them up indivi­dually in appropriate-sized pots. Alternatively they may be removed from the container and the roots teased apart to form individual plants which can be planted up with a little more space in a larger decorative plant bowl.

Although few of the plant bowls purchased ready-filled with plants will have drainage holes in the bottom, it is, nevertheless, of the utmost importance that all such containers should be placed on a protective mat of some kind and not directly onto tables or other furni­ture. From almost all such containers there will be a certain amount of moisture seepage that will damage most wood surfaces on which they are placed.

If you are planting your own container with plants the best beginning will be to acquire an attractive container of reasonable depth, and of a size that will accommodate a reasonable number of plants without undue crowding. The depth of the container should be able to take the rootball of the plants without need for it to be reduced in size by removing surplus soil. Any mutilation of the root system of growing plants will cause them to have a set­back from which they may not recover.

Prior to planting the container should be filled with a drainage layer of coarse gravel and peaty soil mix and the plants should then be individually planted into it, each plant being firmed into position before the next is intro­duced. At all costs the temptation to over­crowd plants should be resisted, as a container filled with too many plants seldom looks attractive, and the plants themselves will do less well as a result of overcrowding. When planting, keep in mind the appearance of the planted bowl some weeks after planting and not the immediate effect that has been created.

The first requirement in choosing the plants is to select those which have the same cultural needs in respect of soil, humidity, light and watering. The plants should form a pleasing mixture of green and variegated or colourful foliage, with contrast in leaf shapes, and the arrangement show a balance of tall, medium and shorter plants. Use of the odd one or two flowering plants will naturally give the plant­ing a more colourful appearance, but flower­ing subjects should be used sparingly as their life is much more limited than the majority of foliage plants and their continual replacement can be a costly business.

To facilitate the replacement of flowering plants it is often advisable to leave them in their growing pots and to plunge the pots to their rims in the surrounding medium. Treated in this way the flowering plants can be indivi­dually watered. This is a help as many may require more frequent watering than the other plants in the arrangement.

On slightly grander scale there are many plastic and fibreglass containers available that range from 45-90cm/H-3ft in diameter, many of which have built-in capillary watering sys­tems. The capillary watering container has an internal platform near the base of the container on which the soil is placed, and below which there is a water reservoir. One end of a water-conducting wick lies in the water while the other end is in contact with the soil. As the soil dries out water is drawn from the reservoir in the bottom of the container, so making thejob of watering comparatively simple and much less hit-and-miss than it normally is. For top­ping up the water supply, a tube runs through the soil and directly into the reservoir. Another tube which runs through the soil into the reser­voir has a level indicator and allows you to check the water level.

In spite of all these apparent refinements, however, many indoor plant growers have very little success with capillary watering units. The main reason for failure is overwatering which is caused by allowing the reservoir to remain permanently topped up with water. It is very much more satisfactory to allow the soil to dry out completely and to remain dry for at least four days before replenishing the reservoir. Allowing the reservoir to dry out will help aerate the soil and prevent it becom­ing waterlogged.

When planting the large containers it is again important to ensure that the plants are not overcrowded, and possibly more important to ensure that reasonably mature plants are used. A large container with a hotch-potch of small plants has much less appeal than the same con­tainer filled with a selection of fewer plants of reasonable size. Also, filling the container with

several plants of one variety will present a more pleasing picture, in some locations, than the same container filled with a general mixture. In this respect Sansevicria trijasciata ‘Laurentii’ is especially fine, as is Schefflera actitiophylla with its large green-fingered leaves. The last men­tioned, the taller-growing ficus varieties and Philodendron hastatum are particularly suitable if attaining height with the plant arrangement is an important factor.

Capillary watering containers and the use of larger plants in them will inevitably involve a considerable cash outlay, so the well-being of the plants is of particular importance. Conse­quently they must enjoy the best possible con­ditions. Plants need good light in which to grow and agreeable warmth that is kept at a fairly constant level. In all new ventures with indoor plants it is wise not to be too ambitious in the use of delicate plants until you have acquired some knowledge of how they are likely to do. Learn with the easier ones before becoming too adventurous is the best policy.

Where space is available indoors you could well be more ambitious with the grouping of plants as there will be scope for larger groups in containers that can be an integral part of the architectural design of the house. Such features can be let into the floor, or they may run the length of the edge of the upper level in a split-level room, possibly with plants trailing over the edge to form a feature in both parts of the room. In large containers you might like to concentrate on one family of plants. In this respect the bromeliad family could, be con­sidered as they are easy to manage, with foliage of a fascinating range of both colour and shape. Also, the colourful bracts can be expected at any time of the year. To give added height to the grouping make up a bromeliad tree by using an old tree trunk of pleasing shape and, with moss and wire, attach the plants to the tree. Simply by spraying the plant and moss with water regularly the bromeliad tree will be an intriguing feature indoors.