Eggplants require a constant temperature of at least 50 degrees Fahrenheit. This can be accomplished by applying a hot cap to the plant when it is in the garden. Be sure to remove the hot cap once the outdoor and soil temperatures are hot enough for the eggplant to thrive without it.
Hardening off of plants is a natural process in which the seedlings are taken outside each day to adjust to the weather before they are planted in the garden. Eggplants are a more delicate plant than other vegetables, and require a slower hardening off than other vegetables. Spend at least an extra week or two hardening off the eggplant before planting them in the garden.
Fertigation can help an eggplant grow new growth at the end of the growing season. Fertigation is a term used to describe feeding plants fertilizer through their regular irrigation system. Fertigation also uses a large amount, usually a full quart, of full-strength fertilizer to pour onto the plant.
Selecting the correct species of eggplant will also help. Small-fruited types of plants will produce more eggplants, whereas hybrids that produce early eggplants will produce fewer eggplants per bush.