How to Grow Physalis Indoors

Fill a 12-inch planter to within 1/2-inch of the top with neutral, sterilized potting soil. Firm the soil well to create an even surface.

Scatter four or five physalis seeds across the surface of the soil. Cover the seeds with a 1/8-inch-thick layer of potting soil so they are just barely covered.

Apply water liberally to the potting soil with a spray bottle. Keep spraying the soil until it feels moist to a depth of 1/2-inch. Maintain moisture at that level while the physalis seeds germinate.

Stretch a portion of plastic wrap across the top of the planter. Set the planter on a warming mat set to 70 Fahrenheit. Position a fluorescent lamp 15 inches above the planter. Keep the lamp on for 10 hours a day.

Watch for germination in four to six days. Remove the plastic wrap once the seeds sprout. Thin out all but two of the physalis seedlings. Remove the weakest ones and keep the most vigorous.

Move the planter to a bright, sunny room where the physalis plants will receive eight hours of sunlight each day. Water the plants once a week with 1/4-cup of water. Let the soil surface dry out between waterings.

Maintain indoor temperatures above 70 degrees during the day or apply bottom heat to the physalis plants with the warming mat. Turn off the warming mat at night to allow the plant time to rest.