Physalis (Physalis ixocarpa) is an interesting annual plant with tall, slender stems and dangling blooms that look like Chinese lanterns. Often known as cape gooseberry or tomatillo, physalis' relationship to the tomato is evidenced by the small berrylike fruits that develop within the paper blooms. Physalis isn't difficult to propagate by planting seeds. Start physalis seeds indoors six to eight weeks before the last expected frost date in your area.
Preparing for Planting
Fill several small peat pots nearly to the top with a good quality commercial potting mixture. Firm the potting mixture evenly with your fingers, then mist the mixture with a spray bottle. Although physalis seeds can be planted in any container with a drainage hole, peat pots are effective for physalis, as the seedlings don't like to be transplanted. Peat pots are transplanted directly in the soil, where the pot eventually decomposes.
Sprinkle two or three physalis seeds in each peat pot. Cover the seeds with no more than 1/8 inch of potting mixture. Place the pots on a tray and cover them securely with clear cling film.
Caring for Seeds
Physalis seeds need bright light and even temperatures in order to germinate. The pots should never be placed on a windowsill, as windowsills tend to be too hot during the day and too cold at night. Instead, place the pots under at least two florescent bulbs. Leave the lights on for a minimum of 12 hours every day and keep the room temperature at about 21.1 degrees Celsius. Adjust the lights as necessary to maintain the pots 4 to 6 inches under the lights. Remove the plastic after the seeds germinate in two to three weeks.
Thin the physalis seedlings when each seedling has at least two sets of true leaves, which are the leaves that emerge after the first tiny, seedling leaves. To thin the seedlings, use a pair of manicure or embroidery scissors to cut the weakest seedlings off at ground level, leaving the strongest seedling intact. Transplant the physalis in your garden after you're sure all danger of frost has passed. Allow 2 to 3 feet between seedling.
Caring for Physalis
Keep the soil lightly moist for two or three weeks after transplanting your physalis seedlings. After that time, water deeply at the base of the plant, then don't water again until the top of soil feels slightly dry. Don't allow the soil to become completely dry. Physalis requires no fertiliser, and excessively rich soil can create lush, green foliage and very few blooms. Pinch back the young shoots to promote bushy, full growth.