Caring For Cacti & Succulents
Almost always teamed together, cacti and succulents have lots in common and several important distinctions. Cacti are part of the succulent family. All cacti are succulents, but not all succulents are cacti. There are hundreds of different types of cacti. The word succulent simply means juicy and fleshy. All succulents have the ability to store water in their flesh. Cacti are succulents with spine cushions called areoles that can bear spines and/or flowers but the plants do not have branches or leaves. Succulents do not have areoles and can have branches and leaves.
To select a healthy cactus or succulent, look for a plant with good color. It should be in a pot large enough to provide the plant stability. Look for signs of recent growth and check to make sure it is firmly rooted.
Situation And Temperature
Almost all cacti and most other succulents can be overwintered at a temperature of 5 degree celsius if kept dry, and cacti grown for flowers usually need this cold winter rest; indoors the window of an unheated room is the best place.
Good light is essential for most succulents, and indoors the sunniest window should normally be used, remembering that the light is one-sided and the plants should be turned occasionally. In sunnier climes full sun in a greenhouse can cause scorching. The risk is reduced by good ventilation and few plants will scorch anywhere in the open air.
Potting mixtures and potting
Cacti and other succulent plants do not require an elaborate potting mixture; the mixture really only needs to be well-drained. Either peat or loam-based mixtures will do, but it is usually an advantage to mix in about one third of extra drainage material such as sharp sand or perlite, as the one thing all these plants dislike is any degree of water logging of the soil.
Potting on -- that is, transferring to a larger pot -- is necessary when the plant has formed a mass of roots; it may or may not be necessary every year, depending on the rate of growth of the particular plant.
Repotting can be carried out by shaking off as much of the old potting mixture as possible from the roots and replacing the plant in the same pot (thoroughly cleaned first) in fresh mixture. Spiny plants can be held in a fold of newspaper. The best time for this is early spring, at the beginning of the growing season; withhold watering for a few days afterwards to enable the roots to recover.
Watering and Feeding
Most succulents grow in spring and summer when water can be freely given each time the potting mixture appears almost dry. In winter, any surplus water can easily cause rotting and complete dryness is normally necessary with green house plants, but indoors an occasional watering may be needed to prevent undue shriveling.
Many succulents, notably the freely flowering ones, benefit from a dose of fertilizer every two weeks during the spring and summer. A high-potassium type, such as is designed for tomatoes, should be used. But plants in soilless, peat-based potting mixtures, which contain no natural food, will need this throughout the growing season.
Succulent plants can be raised from seed, which unless bought from a specialist nursery will probably be 'mixed'. Sow as for any greenhouse perennial at a temperature of 18-24 degree celsius. Be in no hurry to prick out; most seedlings can remain in the same pan for a year, unless very crowded. Keep them slightly moist and not too cold for their first winter. Plants that form offsets can be propagated by removing one or more, allowing them to dry for a few days to reduce the risk of rot before potting them.
The main pest of these plants is the mealy bug, often seen as white cotton-wool patches and sometimes mistaken for a fungus. The pest itself hides within this, but sometimes appears, looking like a miute white woodlouse. Treatment with a proprietary spray will usually control these bugs. But watch out for a more insidious relative, the root mealy bug, when you are repotting; minute white pateches on the roots indicate this. Dip teh infected roots in an insecticide before repotting and water occasionally with a similar substance.