San Diego reader Don Skolnik wrote to our SoCal Garden Clinic to ask if eggplant can be grown as a perennial. This past summer, Skolnik said, he grew a Black Beauty eggplant bush in a 15-gallon container.
"It grew to be 3 feet tall, and it produced lots of medium-size, delicious eggplants," he said.
"What should I do with my eggplant bush during winter to prepare it for next season? Should I heavily prune it back to short and stubby stems? How should I water and fertilize it? Should I repot it in new soil in the spring?"
For an answer we turned to Yvonne Savio, manager of the UC Cooperative Extension's Common Ground Garden Program for Los Angeles County, who oversees the training of master gardeners.
Congratulations on last year's successful harvest. The plant is in the same Solanaceae family as tomatoes and peppers, so it may grow from year to year, depending on the climate.
I grew some pepper plants for five years before the yields were so reduced that I pulled them out. In the fall, I pruned the branches to the lowest new growth. I incorporated more manure and compost into the soil and kept it barely moist. And I provided overhead frost protection during threatening spells.
In the spring, I also planted new 4-inch plants to compare the vigor of growth and harvest, expecting the old plants to outgrow and outproduce the new ones. However, the old plants and the new ones initially grew at the same rate and yielded the same number and size of fruits. You may not need to pull them out for a few years or until a hard frost.