Sun-loving cactus plants are those that appear the way we normally expect a cactus to look. They are native to arid desert regions where they receive direct sunlight for a large portion of the day. In the home, these plants should be placed in a window with a south or west exposure where they will receive direct sunlight for at least a few hours each day.

The quantity and frequency of watering provides one of the biggest dilemmas to cactus owners; and since a cactus does not wilt at the first sign of drought stress, the plant itself offers few cues to a need for water. A good rule of thumb is to water when the top 2 to 3 centimetres of soil is dry. This should be adjusted with season, however, as plants will require more water during the period of summertime growth than they will during the slowed, or halted growth of winter. In winter the plants may require water only once a month. During winter you should supply just enough moisture to prevent the roots from drying and dying. One of the most important considerations in watering a cactus is that the pots must never be permitted to stand in water. Waterlogged soil can quickly lead to rotting of the roots with disastrous consequences for the plant.

                The growing medium also plays a role in watering and plant health. Contrary to popular belief, most cacti do not prefer to live in pure sand. In nature, they may be found growing in sand, but this is only because they are able to survive in conditions where the plants which compete with them for space cannot. Cacti are not found naturally on rich soils, simply because the other plants that can survive on these soils have crowded the cacti out. In the home, where competition from neighbouring plants has been eliminated, cactus plants will respond favourably to a rich soil that is free-draining. While cactus soil mixes are available, you can make your own by combining two parts peat-based potting soil with one part very coarse sand or grit. Fertilizer can be added to every second watering during the summer, with the frequency and concentration of fertilizer being reduced in winter. Either a specially formulated cactus fertilizer can be used, or fertilizer such as 15-15- 30 which includes minor or trace elements.

While most cacti tolerate a wide range of growing temperatures, most will do best at temperatures similar to that of most other house plants. When temperatures are either too hot or too cold, a cactus will often simply go dormant. An ideal placement for a cactus in winter would be a sunny cool room. During the summer, cacti will appreciate being moved outdoors where they can receive brighter light in combination with cooling breezes during the day and cool humid conditions during the night. If moving your cactus outside for the summer, be sure to place it in a position of partial shade for the first few weeks, and slowly move it to a sunnier location. A plant going directly outside into full sun will likely be scorched by the more intense light found outside the home.

Shade-loving cacti are those members of the cactus family that would normally be found growing in moist tropical jungles. They frequently have a trailing growth habit and flattened stem segments like those seen on the familiar Christmas cactus. Since they are native to the same areas where many of our more familiar tropical plants originate, they tend to thrive under conditions similar to those for other house plants. They do not tolerate intense sun, but will thrive in an east window. They also grow quite well under artificial lights. Since flowering on many tropical cacti is begun in direct response to the length of day, plants grown under artificial light should have the daylength reduced in winter so that they are in darkness for more than 12 hours each day. Without these shortened days, such plants will not flower.

                Like many jungle plants, these types of cacti do not have an annual period of dormancy and will require even moisture throughout the year. Since shade- loving cacti continue to grow throughout the year, they require a more regular supply of nutrients and will benefit from mild fertilizer at the time of watering. They can be fertilized at the same strength as sun-loving cacti, but on a more regular schedule. Like other cacti, they require a free-draining growing medium, and should never be permitted to stand in water.

Jungle cacti tend to be less tolerant of temperature extremes. If a tropical cactus is placed outdoors for the summer it should be placed in the shade of a tree where they will receive bright but filtered light.