Eggplants benefit significantly from structural assistance because they are heavy producers with relatively brittle stems. Providing support is a preventative measure that protects the plant from damage and improves both the quality and quantity of the harvest. Growers should plan to incorporate a support system as a standard practice when cultivating these large, fruit-bearing plants.
Why Eggplants Require Structural Support
Eggplants are members of the Solanaceae family. While their stems become somewhat woody as they mature, they are not robust enough to carry a heavy fruit load. The plant’s structure is bushy and multi-branched, creating many junctions that are prone to snapping under stress, particularly in windy conditions.
Individual fruits can weigh a pound or more in large varieties like ‘Black Beauty,’ and smaller Asian types often produce many fruits, leading to a substantial cumulative weight. This weight causes branches to droop and the plant to potentially topple over, which can sever the main stem or damage the root system. Allowing fruit to rest on the ground increases the risk of soil-borne diseases and pests, leading to fruit rot. Keeping the foliage and developing fruit elevated ensures better air circulation, reducing fungal and bacterial issues like leaf spot and wilt.
Comparing Support Systems: Cages, Stakes, and Trellises
Gardeners use three primary methods for supporting eggplant: cages, stakes, and trellises. Cages offer a hands-off approach for bushier, compact varieties, such as those suited for container gardening. However, lightweight tomato cages are often too weak for a fully-laden eggplant, making sturdier options like concrete reinforcing wire cages a better choice.
Staking is a highly effective method for larger, taller varieties that require more targeted support. This method uses a single, tall stake—made of wood, bamboo, or metal—driven deep into the soil near the main stem. The main advantage of staking is the ability to tie the central stalk and heavy branches directly to the support, customizing the assistance as the plant grows. This system also works well for plants grown in rows, where a single stake per plant is efficient.
Trellises, which involve a network of wires or mesh strung between posts, are ideal for vining or smaller varieties and are excellent for maximizing space in small gardens or raised beds. This method allows for multiple plants to be supported in a linear fashion, often using horizontal lengths of twine between sturdy end posts. Trellising is particularly beneficial for long, slender fruit types, as the elevated growth encourages uniform, straight fruit development.
Installing Support and Timing
Supports should be installed at the time of transplanting the seedling into the garden bed or container. This timing is crucial to prevent root damage and ensure the plant’s long-term stability. Waiting until the plant is large and fruiting risks spearing the established root system when driving the stake or post into the ground.
For staking, drive the support structure six to eight inches away from the main stem, securing it deep enough—about a foot—to withstand the weight of a mature plant and wind. As the eggplant grows, the stems must be tied to the support using a soft, non-abrasive material, such as garden twine or strips of cloth. Use a loose figure-eight knot around the stake and the stem to prevent the tie from cutting into the stem as it thickens. Regular maintenance, including checking and adjusting these ties, is necessary to accommodate the plant’s rapid growth and ensure the support remains effective throughout the season.