Succulents are a diverse group of plants defined by their ability to store water in specialized tissues, making them highly resilient to arid conditions. These low-maintenance species, which include cacti, are favored in gardens and containers for their unique forms and textures. Companion planting involves placing different species together so they can share resources and mutually benefit. Successfully combining succulents with other plants requires a careful understanding of their specific environmental needs to ensure all species thrive together.
Understanding Compatibility Requirements
The foundation of a successful succulent garden rests on matching the environmental demands of all the plants involved. The most significant requirement is the growing medium, which must allow water to escape rapidly. Succulents are highly susceptible to root rot in prolonged moist conditions, necessitating a soil mix that is gritty, sandy, or rocky.
Standard potting soil retains too much moisture and must be amended heavily with materials like perlite, pumice, or coarse sand to achieve fast drainage. The watering regimen must follow a “drench between droughts” principle. All companion plants must tolerate the long dry periods succulents require, as frequent watering for one species will harm the others.
Almost all succulents and their companions require uniform access to bright light, often for six or more hours per day. Pairing sun-loving varieties with those that prefer shade leads to problems like etiolation, where plants stretch for light, or sunburn. Matching these three factors—soil, water, and light—is the prerequisite for any harmonious planting.
Pairing Different Succulent Varieties
When combining species within the succulent and cactus families, success depends on aligning their growth cycles and managing their potential for dominance. Grouping plants by their dormancy period is important; for example, planting summer-dormant species like Aeonium and Kalanchoe together. Winter-dormant plants such as Agave, Echeveria, and Sempervivum should be paired to ensure they receive the correct care during their active growing phase.
Beyond care requirements, pairing is often guided by aesthetic contrast in color, texture, and form. Combining a smooth-leaved plant like a blue-gray Echeveria with the spiky texture of an Opuntia cactus creates significant visual interest. Using colors opposite each other on the color wheel, such as a red-tipped Crassula against a cool-toned blue Sedum, makes the arrangement more dynamic.
Mixing plant heights is an effective strategy, using upright forms like Sansevieria as a vertical anchor, low-growing Sedum as a filler, and trailing species like Senecio as a spiller over the edge of a container. Also consider the thickness of the leaves, as thinner-leaved varieties, like Portulacaria afra, generally require slightly more frequent watering than their thick-leaved counterparts.
Selecting Non-Succulent Companion Plants
To introduce variety and complexity, non-succulent plants must be chosen specifically for their ability to tolerate the same lean, dry conditions. Drought-tolerant herbs are excellent companions because they naturally thrive in low-fertility, well-drained soil and often share a preference for full sun. Rosemary (Salvia rosmarinus), Lavender, and Lemon Thyme are prime examples that provide contrasting, fragrant foliage and texture.
Ornamental grasses are a valuable addition, offering fine texture and movement that contrasts sharply with the rigid, fleshy nature of most succulents. Low-growing varieties like Blue Fescue or the rust-colored Orange Sedge (Carex testacea) share the required drought tolerance and do not compete aggressively for nutrients.
Flowering perennials and shrubs are also suitable, provided they are adapted to xeriscaping or rocky conditions.
- Yarrow (Achillea millefolium)
- Red Valerian (Centranthus ruber)
- African Daisies (Osteospermum)
- Santolina (Lemon Fizz)
These plants flourish with minimal water and add bursts of color that succulents often lack. The silvery, fine-textured foliage of Santolina also provides a soft foil to the heavier succulent forms.
Design and Placement Strategies
Effective design goes beyond plant selection to include the physical arrangement and root management of the garden. When planting species with different root systems, especially in containers, strategic soil layering can accommodate minor differences in water needs. For example, a slightly richer potting mix can be blended around a companion herb’s root ball, while surrounding succulent roots remain in the pure, gritty cactus mix.
Visual appeal is enhanced by utilizing the “thriller, filler, and spiller” concept. This involves positioning a taller, architectural plant (thriller) in the center or back, mounding plants (filler) around it, and trailing plants (spiller) along the edges. This framework ensures a balanced composition that highlights the unique structure of each species.
In ground plantings, such as rock gardens, placement can manage light exposure functionally. Taller ornamental grasses or shrubs, like a Rockrose, can provide light, filtered shade during intense afternoon sun. This is beneficial for certain succulents prone to sunburn, ensuring both groups receive optimal light levels without one compromising the other.