In generations past, a few ferns, palms, aspidistras and seasonal-flowering pot plants were the only ones available for interior decoration. Then, in recent decades, a tremendous interest in house plants arose. Both those grown for their flowers and valued for their foliage in great variety found favour and are cultivated in vast numbers in houses, flats, offices and other places of business.

Thanks to improved lighting and heating, many plants formerly able to flourish only in conservatories or hothouses now thrive as house plants. With proper climate control, assuring favourable temperatures and humidity, the most delicate flowering kinds will keep in bloom for weeks, and a number of the foliage plants, such as cissus, will last for years.

All house plants are really only at home outdoors. Many come from dense jungles, often starting life in the deep shade of a foliage canopy, gradually moving upward to claim their share of sunlight. This probably makes some plants adaptable to indoor conditions.

House plants can, however, be grown successfully without recreating a jungle. The key to success is remembering that warmth, moisture and light need to be kept in reasonable ratio. If warmth is decreased, moisture should also be decreased. Where light is poor, warmth and moisture should be reduced also.

Poor light and high temperature are common causes of problems. Blinds or curtains are often drawn during weekdays in working households. Sun on glass or other parts of the building makes the rooms hot. Then, on the days when the household is
at home, the rooms are bright and sunny. Plants find it hard to adapt to these changes.

This high temperature, low light condition causes weeping figs, jade and some other plants to drop foliage suddenly and new growth to become weak. In hot and dry situations, tips and edges of leaves will brown and shrivel. Cold conditions and wet soil make many house plants rot, especially snake plant (sanseviera), pedilanthus, desert cacti, ixora and some pileas.