Planting cacti and succulents together is absolutely possible, creating appealing and popular mixed arrangements. These plants share a reputation for being low-maintenance and thrive in similar harsh conditions. Success in combining them, however, depends entirely on understanding and carefully managing the subtle differences in their individual care requirements.
The Definition Difference
Every cactus is botanically a succulent, but the reverse is not true. A succulent is any plant adapted to store water in its leaves, stems, or roots to survive in arid environments, encompassing over 60 plant families. Cacti belong exclusively to the Cactaceae family, making them a specialized subset of succulents. The defining feature separating a true cactus from all other succulents is the areole, a specialized, cushion-like structure found on the stem. Spines, flowers, and new growth emerge only from this areole, an adaptation unique to cacti.
Essential Shared Environmental Needs
Most cacti and non-cacti succulents align closely on their needs for light and temperature, which supports successful mixed planting. Both types demand high light levels to maintain compact growth and vibrant coloration. They generally require at least six hours of bright, direct or indirect, light daily. Temperature requirements are also consistent, as both groups prefer warm environments typical of arid regions, thriving between 65 and 90 degrees Fahrenheit during their active growing season. Crucially, almost all cacti and succulents must be protected from frost, as freezing water stored in their tissues causes irreparable damage.
The Critical Divergence: Water and Soil
The primary challenge in mixed planting lies in the differing moisture tolerances of cacti and succulents. Cacti evolved to survive extreme drought and are highly susceptible to rot if their roots remain damp. They require the soil to dry out completely, often needing a deep soak only every two to four weeks. Leafy succulents, such as Echeveria or Sedum, can tolerate slightly more frequent watering. Although they still need the soil to dry between waterings, their leaves allow them to draw moisture more continuously than desert cacti, creating a potential watering conflict.
This divergence extends to the soil, as both groups require a well-draining, porous substrate to prevent root decay. Cacti generally benefit from a grittier mix with a higher ratio of inorganic material, such as pumice or perlite. Leafier succulents can tolerate a mix with a slightly higher percentage of organic potting soil, which helps anchor their roots while still allowing for rapid drainage.
Strategies for Successful Mixed Planting
To overcome moisture differences, select species with highly compatible watering needs, such as pairing arid desert cacti with drought-tolerant succulents like Haworthia or Lithops. Avoid combining them with jungle cacti, which prefer more humidity and organic material. Choosing a wide, shallow container with ample drainage holes is beneficial, as the large surface area encourages faster soil drying. You can also create microclimates by planting the most water-sensitive cacti in slightly mounded areas that dry out first.
An advanced technique involves partially burying the roots of water-sensitive cacti, placing only the bottom one-third of the root ball beneath the soil line. The exposed roots are then covered and disguised by neighboring plants, limiting the cactus’s access to bulk soil moisture. For watering, adopt a deep but infrequent schedule tailored to the plant with the lowest water tolerance, typically the desert cactus. Wait until the soil is completely dry several inches down before thoroughly soaking the entire container. This ensures both plant types replenish their reserves without leaving the roots susceptible to rot.