The tree does not always come true from seed, but is most likely to if one is careful to take seed from red fruits with black seed pulp or yellow fruits with yellow seed pulp. Germination is accelerated by placing washed and dried seed in a freezer for 24 hours before planting out. The leaves are removed and the base cut square below a node. Cuttings can be planted directly in the ground, but should not be permitted to fruit the first year. The tamarillo is generally regarded as pest-resistant, although they are occasionally attacked by green aphids, and fruit flies will attack the fruit in areas where that is a problem.
Nematodes are also a potential problem.
The principal disease is powdery mildew, which may cause serious defoliation if not controlled. The plant is noted for its resistance to tobacco mosaic virus, though it is susceptible to cucumber mosaic virus and potato virus. Die-back, of unknown origin, at times is lethal to the flowers, fruit cluster, twigs and new shoots. Potted plants grown inside should be watched for the common house plant pests, such as mealybugs, cottony scale and white flies. To harvest, simply pull the fruit from the tree with a snapping motion, leaving the stem attached.