Modern houses make possible and often necessary a new kind of gardening, the use of indoor garden planters. These troughs, bins, boxes and beds serve as integral architectural and furnishing units. If well-planned and well-managed, they add immensely to the appearance and livability of a home.

The need for the bold effects and patterns that living plants can create results largely from the architectural simplicity and sometimes severity of modern interiors. Expanses of plain wall, picture windows and extensive surfaces of glass brick invite the use of vegetation as contrast and relief. Ample light from generous windows and even air-conditioning in some houses, combine to afford favourable growing conditions for a wide variety of plants.

Modern houses afford places for planters against various backgrounds and in many different settings. Glassed-in and skylighted areas are especially favourable. The base of a picture window is an ideal place for a planter. If the window extends to the bottom of the wall, a built-in bed, level with or only slightly higher than the floor is ideal. A complementary planter on the outside of the window makes it possible to relate plants growing outside with those inside and achieve a most convincing transition from indoors to outdoors. Planters are effective as room dividers, as screens, and as features that supply interesting patterns of stems and foliage. They do much to bring into the house a feeling of the outdoors.

Planters can be of any dimensions and shapes appropriate to their locations. Some enthusiasts have floor-level, bed-type planters
large enough to include a fountain and perhaps a path to make servicing them easier. These are truly indoor gardens! But most planters are less elaborate. They may be built-in or portable, at floor level or raised. They may be of wood, masonry or other appropriate material. Their interior depth should be from 8 to 12 in., or more in exceptional circumstances, as, for instance, a built-in ground bed that contains large "trees". Whatever the material of which the planter is constructed, it should have holes in its bottom to ensure adequate drainage and its inside should be covered with two or three coats of asphalt paint. If desired, a liner box of zinc, aluminium or galvanized steel, but not copper, can be used. This also must have drainage holes.

Before setting the plants, an inch or more of coarse gravel or cinders is placed in the bottom of the planter to encourage drainage. The plants may then, without being removed from their pots, be arranged, raised if necessary on blocks of wood so that the rims of the pots are not more than an inch below the surface after peat moss or vermiculite has been poured in between the pots. Or the planter may be filled with porous soil and the plants set in it after they are removed from their pots. The first method makes it easier both to replace a plant that is failing and to rearrange the plants to provide change; moreover, somewhat better control of watering is achieved if plants with different needs are used in the same planter.
Arranging the plants gives opportunity for artistic expression. So far as is possible, in any one planter, use plants having the same general requirements. Do not, for example, mix cacti and African violets, and don't mix moisture and shade-loving ferns with a plant that prefers dry soil and sun, such as crown-of-thorns.

Plants of varying sizes, some almost ceiling high and others low ground covers, may be used in the same arrangement. Trailing plants are especially useful for draping the sides of raised planters. Vines, trained on trellises, bamboo stakes or wires are excellent. For dramatic effect choose large-leaved plants such as dieffenbachias and rubber plants.

The care of the plants does not differ materially from pot-grown specimens, except that less frequent watering will be necessary. Prompt measures must be taken to eliminate any harmful insects that infest the plants. The foliage should be kept clean by sponging it with sudsy water occasionally. Some fertilizing and, in some cases, pruning will be needed. Almost any house plants that are reasonably permanent can be used in indoor garden planters.