Yes, you can plant cabbage and Brussels sprouts together because they are both cultivated forms of the same species, Brassica oleracea, belonging to the Brassicaceae family. Cabbage (Capitata Group) forms a large, tightly packed terminal bud near the ground. Brussels sprouts (Gemmifera Group) develop small, edible lateral buds along a tall, upright stem. This shared species origin creates a horticultural opportunity, but it also carries significant risks that every gardener must acknowledge before attempting co-planting.
Compatibility Factors: Shared Requirements
The shared species origin means that cabbage and Brussels sprouts have nearly identical environmental requirements. Both are classified as cool-season crops, performing best when daytime temperatures remain within a range of 65 to 80 degrees Fahrenheit. They also demand a full sun location, needing at least six hours of direct sunlight each day. Ideal soil conditions include a rich, well-drained loam that has been heavily amended with organic matter like compost. They are considered heavy feeders, requiring consistent access to nutrients for their development. The plants thrive in a slightly acidic to neutral soil pH, with a preferred range between 6.0 and 7.0, which maximizes nutrient availability and discourages certain soil-borne diseases.
The Risk of Shared Pests and Disease
The primary drawback of co-planting is their shared susceptibility to the same biological threats. Placing two Brassica species in close proximity creates a high-density environment that functions like a monoculture for pests. This concentration of host plants rapidly amplifies biological problems, leading to faster and more severe infestation or infection. Common enemies such as the Imported Cabbageworm and Cabbage Looper easily migrate between the crops, feeding on the foliage. Flea beetles are another shared pest that causes significant damage to young seedlings by chewing small holes in the leaves. Close planting also increases the risk of spreading soil-borne fungal diseases, most notably Clubroot, a pathogen that distorts the roots and stunts plant growth. Maintaining a rotation schedule becomes much harder when two susceptible crops are grown side-by-side.
Essential Spacing and Nutrient Management
Successful co-planting requires attention to physical spacing and resource allocation due to the plants’ differing growth habits. Cabbage typically grows wide and low, requiring 12 to 18 inches between plants to allow for the formation of large, dense heads. Brussels sprouts are tall and vertical, needing 18 to 24 inches of spacing to accommodate their height and ensure good air circulation around the central stalk. This careful separation is necessary to prevent overcrowding, which can lead to poor air flow and encourage the development of fungal issues.
Both crops are heavy feeders that quickly deplete the soil of nutrients, necessitating a constant, supplemental feeding schedule. Nitrogen is a particularly high demand for both, as it drives the leafy growth of cabbage and the stalk development of Brussels sprouts. A starter solution applied at transplanting, followed by a nitrogen side-dressing about a month later, is often required for sustained growth. Attention to calcium is also important, as brassicas need this mineral for strong cell wall development and to prevent disorders like tip-burn in cabbage. To manage the heavy draw on soil nutrients, a gardener should consider staggering the planting times, as Brussels sprouts require a much longer growing season.