Cactus care guidelines vary greatly upon the specific conditions in your garden. The instructions for cactus care in a hot, dry environment like Phoenix is much different than the care instructions for cool, damp locations. Generally, cacti and succulents like to be kept warm and bright and like their soil to be dry. Cacti are very tolerant of less than ideal circumstances, but better conditions derive better results.
Upon receiving your bare root cacti plants, open boxes as soon as possible. If any damaged roots are observed, trim with clean scissors before planting. Keep the new cactus plants somewhat dry until new roots start forming. This can take a few days or weeks if there is hot weather or longer if dormant. During the shipping process, some cactus plants may become de-acclimated from their normal full sun environment, and could burn if they are exposed too soon to extremely hot sun.
When you receive your cactus cuttings, allow it to dry 10 to 45 days before planting. (Thick cuts and cool weather require a longer drying period). To dry the wounds, leave the cutting in a shady, warm exposure, not direct sun. Then plant it in DRY cactus potting soil and do not water for another 10 - 45 days. After the cutting develops a root system it is safe to start a light regular watering cycle. Always let the soil dry out completely between applications of water. It is MUCH more likely that a cutting will be killed by over watering than under watering.
It is difficult to provide precise rules pertaining to the watering of cacti and succulents. Cacti should not be watered during their period of dormancy, which occurs during the winter months. During winter, keep cacti dry, especially if kept in an environment with a fairly low temperature. Cacti must be watered during their active periods.
A typical watering schedule (if the plants are sheltered from rain) might be: once in January, once in February, twice in March and 2 to 4 times monthly during the growing season, depending on the conditions.
Enough water should be given to soak all the soil in the pot. Excess water should drain freely. During summer, occasional rain showers will do no harm. Plants prefer rain to tap water. During a protracted period of rain, however, cacti should be placed in a sheltered area.
Technically, water should be free of chlorine and alkaline salts, but ordinary tap water will suffice. Chlorinated water and hard water will leave white stains on the cacti, which is unsightly and does block the stomata. (pores)
Cacti and Succulents need regular feeding during their growing season (Spring-Summer). They need a balanced range of minerals. Potassium (K) to encourage flowers and fruit, Phosphorus (P) for good root growth, and Nitrogen (N) for vigorous top-growth. Cacti also need other trace elements. Any commercial houseplant fertilizer will do, but an ideal ratio of nutrients is: 20% nitrogen, 20% potassium, 20% phosphorus, and all of the other trace elements.
Mature cacti and succulents grow well in a warm climate at a minimum temperature of 61F (16C). Cacti usually need direct or filtered sunlight to perform photosynthesis. Natural light can be supplemented by an artificial light source such as fluorescent lighting.
Cacti have adapted to survive in rocky, sandy, or clay based soils, with limited nutrients. However, the ideal soil or potting mixture will draining rapidly and yet retain some moisture. Always use a gritty mixture, pumice is great, to ensure correct drainage. Most cacti prefer a slightly acidic soil.
Succulents and cacti do not require a great depth of soil. Make sure that all containers have drainage holes. Line the bottoms with material such as pottery shards or gravel before adding soil. When growing plants together in one container, select plants with similar cultural needs and growing seasons. Many slow-growing succulents do well when planted with desert cacti.
Cacti do resist pests and diseases, but can fall victim to mealy bug and scale as well as numerous fungal and viral attacks. The remedy for scale and mealy bugs are varied, but I find Malathion and Orthene with a wetting agent to be very effective. Regards to fungal and viral attacks, prevention is the best remedy. That is providing good growing conditions and be on guard for excess moisture. Fortunately desert plants are very tolerant to imperfect conditions. Provide the range of correct conditions and the cactus will do the rest. Happy gardening!
Bare Root: An established plant with roots; soil removed before shipping.
Cutting: A cutting from a parent plant. The cutting will establish roots after it has been correctly planted.