The eggplant shrub (Solanum melongena) thrives as a perennial in U.S. Department of Agriculture plant hardiness zones 4 through 10, but it's typically raised as an annual vegetable. This plant does best in well-drained soil in full sun and is prized for its smooth, dark, glossy fruit. Pruning and trimming your eggplant increases the plant's overall health and also ensures the biggest, juiciest fruit.
Disinfecting the Pruning Tools
Eggplant stems are thick, hard and spiny. To trim the plant, you'll need a sharp pair of pruning shears or a sharp knife. Before pruning, disinfect the tools. This minimizes the risks of spreading various plant diseases.
Simply soak your garden tools for five minutes in a homemade disinfectant solution made from one of the following recipes:
- 1 part pine oil-based cleaner and 3 parts fresh water
- Equal parts rubbing alcohol and fresh water
- 1 part household bleach and 3 parts fresh water
After soaking the knife or pruning shears, rinse the tools under running water and allow them to air dry before cutting the eggplant shrub.
Pruning the Eggplant's Branches and Foliage
Regular pruning keeps the eggplant looking tidy while also improving plant health, vigor and resistance to disease.
Pull on a pair of garden gloves. This protects you while handling sharp garden tools and also shields your hand when handling the spiny eggplant stems.
Cut off sucker branches as soon as they appear on the plant. Suckers are any stems that sprout from around the bottom main base of the eggplant shrub. If they're not removed, the suckers will compete with the main stems for the plant's energy, resulting in an overall weaker plant.
Inspect the eggplant's main stalk. You'll notice that the main stalk divides into two main stems with lateral side branches growing from above and below the main stem division.
Cut off any lateral, side branches other than the two main stems and one side branch below where the main stalk divides into two. This keeps the eggplant shrub strong and compact. Continue to observe the eggplant and remove new side stems that may begin to grow.
Trim the bottom leaves off of the eggplant as they slowly wilt, turn yellow and become brittle. This enhances air circulation and minimizes the risks of plant disease.
Thinning out the Eggplant Fruit
When it comes to the fruit on your eggplant shrub, more is not necessarily better. For larger, more plump eggplant fruit, thin the fruit out after the plant flowers and juvenile fruit appear. Using a knife or pruning shears, snip off most of the fruit and only leave one fruit per branch. This allows the plant to invest all of its energy into a select few fruit, resulting in a bigger, more flavorful harvest.