Caring for Cacti and Succulents


Compile a general profile of cacti and succulents to determine best practices for care and nurturing by researching details such as recommend methods for planting, watering, soil, sunlight requirements, pruning, fertilizing, pest management, disease management, and freeze care. Differences between indoor and outdoor plants and their needs, including freeze tolerance in separate regions of the U.S., will be highlighted.

Early Findings

General information

  • Feeding: Succulents and cacti do best when fed fertilizer once per year. A half-dose of a well-balanced fertilizer applied at the beginning of the plant's growing season will give the best results.
  • Feeding: The ideal fertilizer for succulents is organic, includes beneficial soil microbes, and contains humic acids. Blends with lower nitrogen and which have a slow-release will favor the plant more.
  • Pests: Common pests attacking cacti and succulents include mealybugs and scale, two species that feed on the plant's inner juices. To remove mealybugs and scale, spray the plant with enough water and force to remove them from the plant without damaging it. Scale will need to be removed with tweezers or fingernails. Once they are mostly removed, spray the plant with insecticidal soap or horticultural oil, and follow up with a rubbed treatment of 50 percent rubbing alcohol and 50 percent water.
  • Planting: When planting in a container, pick a coarse potting mix to enable the best draining and aeration, avoiding overly rich or moist blends. Adding perlite or pumice at a ratio of up to 50 percent will further improve the drainage potential. Before putting in the succulent, wet the mixture to evenly spread moisture throughout the soil.
  • Container choice: Containers with large drainage holes are strongly preferred. Glass containers should be avoided except for short term situations, as without drainage the roots could rot in the long term.

Outdoor cacti and succulents

  • Sunlight and temperature: Outdoor succulents do best in zones 8, 9, and 10 in areas of abundant natural sunlight and warm temperatures. For areas with colder winters, Sempervivums can grow in zones 4-8, and stonecrop sedums can grow in zones 4-9.
  • In direct sun, when the temperature exceeds 90 degrees, most succulents will require some form of sun protection. Smaller species are most vulnerable to high, hot sun conditions and will definitely need shade when these conditions are extended.
  • Watering needs: Some succulents, such as Portulacaria afra, Crassula arborescens undulatifolia, and Aeonium zwartkop prefer to have additional water, and will do better in rainier climates. These can sometimes be identified by their thinner leaves.
  • Watering needs: Other succulents, such as Graptoveria 'Fred Ives', Pachyveria glauca, and Aloe brevifolia, and cacti such as Mammillaria rhodantha and Mammillaria gracilis fragilis, need much less water and will do well in areas of drought. These can be identified by their thicker, plumper leaves.
  • Frost: In areas where frost is an issue, it could spell the end of the succulent unless it is protected. Planting the succulent in a container that is small enough to carry inside is a sure-fire way to ensure it won't be damaged if it is moved in time. For outdoor-only plants, avoid watering them before a frost to give them the best chance of survival.
  • Pest control: If the infestation of mealy bugs or scale is large or tenacious, a treatment of systemic insecticide may be required. If necessary, insecticides using imidacloprid should be avoided whenever possible as these are lethal to pollinators.

Indoor cacti and succulents

  • Lighting needs: Most succulents prefer indoor locations with high sun, but some species, such as mother-in-law tongue, do well in low light conditions indoors. Sunlight needs and container size will be dependent on the species of succulent you choose.
  • Watering: To determine when an indoor succulent or cacti should be watered, observe it - if its leaves are dull, shrinking or puckering, that is a sign that it needs water. To be sure, put a finger into the soil near the roots up to the second knuckle. If it is dry, give it water, ensuring that the amount given drains quickly enough so the plant doesn't sit in it overnight.

Research proposal:

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