Pomegranates are tropical and subtropical trees that when mature, produce edible fruit that ripens six or seven months after flowering. While pomegranates are usually planted outdoors, you can successfully grow them in a greenhouse. You can transplant your trees outdoors in two years, if desired.
Grow pomegranates from seeds in trays. Use all-purpose potting soil that is well-draining. Sow seeds just below the soil's surface. Keep the soil moist, but not saturated. Wait for the seeds to germinate and get big enough to safely handle.
Move the seedlings to individual pots. As the trees gets larger, you will need to transplant them into larger containers. Start with gallon containers and then, over the years, move them to 5-gallon and then 10-gallon containers. Keeping the trees in pots that are suitable to their size makes watering them is efficient (not wasted in too much soil) while still giving the roots plenty of room to grow.
Fertilize your pomegranate trees two times a year, but not right after planting. Generally, outdoor pomegranates are fertilized in November and March, so you can follow this schedule, especially if you plan to transplant your trees outdoors. Use about 2 lbs. of fertilizer labeled 8-8-8 for the first couple of years and then about 5 lbs. when they are mature.
Prune off dead branches in the winter, and at anytime, remove any suckers that grow next the main trunks and use essential nutrients and water. When the pomegranate trees reach 2 feet, cut them back so that four or five healthy shoots from the main trunk are allowed to grow in a way that the tree is uniform. The lowest shoot should be one foot from the ground so good trunks are formed. For the first three years, prune these same shoots back a bit each year. After three years, little pruning is needed except to remove dead branches and suckers.
Keep your pomegranate trees evenly moist, especially during the first season. However, they can tolerate some mild drought conditions, but will produce better fruit if the soil is kept slightly moist.