If you want your pomegranate bush or tree to produce fruit there are certain things you can do to help facilitate this process.
First, before getting into any details, there are two basic types of pomegranate plants: fruit bearing, and flowering. Both types will produce flowers but only the fruit bearing varieties will produce fruit. So, make sure that you didn’t purchase an ornamental tree or bush grown only for its flowers!
Secondly, there are many varieties of fruiting pomegranate on the market these days. Though some are more cold hardy than others, most varieties are hardy in USDA Plant Hardiness Zones 7 to 11. That being said, before purchasing and planting a pomegranate make sure that you choose a variety known to be cold hardy in your area.
If you have a proper fruiting variety and are in the right USDA Hardiness Zone, but your tree has not produced fruit, read anf follow the guidelines below and you should be harvesting an abundance of fruit.
Sun Needs
Pomegranate prefer as much sun as you can give them, however light shade is tolerated. Six or more hours of sun a day is necessary to produce fruit. Just keep in mind that the more shade there is the less flowers and fruit will be produced. Some varieties will get mildew if planted in too much shade.
Soil Requirements
The difference between pomegranates and many other fruit trees is the wide range of soils in which the pomegranate will grow. From heavy clay, black loam, lime rich soils, dry rocky hillsides to sandy soil, the pomegranate will grow almost anywhere. They grow best in fertile, deep, loam soil that is rich with humus, as do most other fruit trees. As many other types of plants require, pomegranate prefers a well-draining soil. Constantly soggy or wet soil can cause problems with their roots. Brief periods of flooding won't cause problems provided the soil is well-draining. If you live in an area that can experience long rainy periods it's best to plant pomegranate on raised beds or mounds. I do this in my landscape due to the heavy clay soil that tends to hold a lot of moisture during the winter season or extended periods of wet weather. Regarding soil pH, they will grow in moderately acid to moderately alkaline soils that range from 4.5 to 8.2 on the pH scale. That being said, they thrive and produce best between 5.5 to 7.2, where most average garden soil fall between anyway. They are considered salt-tolerant, but accumulation of salts in the soil in excess of 0.5% is harmful, though this is way above what the average gardener will find. If you live in an area that has high salts in the soil or water, plant the pomegranates on raised beds so the salts can drain away.
Fertilization
Unless you have a very sandy soil, pomegranates need very little fertilizer. That's why you shouldn't grow your pomegranate in a lawn area where it will most likely receive too much fertilizer.
The only element pomegranates really need is nitrogen, and how much is applied will depend on the age of the plant. Don't fertilize pomegranates at all during their first year of life. Apply about 2 ounces of nitrogen per plant during the second year in spring, immediately after pruning. Each year therafter you can add another ounce. By the 5th year 6 to 8 ounces of nitrogen per tree. A mature tree of 15 years needs about 12 ounces (3/4 pound) of nitrogen per year. These figures are actual nitrogen. No bag of nitrogen fertilizer is 100% nitrogen. So you'll have to do a little math. If your nitrogen fertilizer is 34% (Ammonium Nitrate 34-0-0) your fertilizer contains 34 pounds of nitrogen per 100 pound bag, 17 pounds per 50 pound bag, 8.5 pounds per 25 pounds, 4.25 pounds per 12 pounds, 2 pounds per 6 pounds and so on. Fertilizer should be applied in late winter, before new leaves begin to emerge in spring.
Alternatively, instead of using commercial fertilizers I simply use mulch and compost. Mulching plants with composted manures and other organic composts can supply the nitrogen that pomegranates need while eliminating the possibility of burning plants. I also apply two cups of bonemeal and maybe a half a cup of Sul-Po-Mag.
Keep in mind that too much fertilizer is bad, so it's better to apply less than more. Too much fertilizer will cause heavier foliage growth, which can effect fruit production and even cause the fruit to drop prematurely. Applying too much fertilizer or applying it later in the year than recommended can cause fruit to mature late, and have poor color and poor taste quality.
Water
Pomegranates are native to hot dry climates and, when well established, will thrive with little attention to water. That being said, to produce good fruits they will need water. On average, to produce good fruit, pomegranates require about 45 inches of water per year either from rainfall or irrigation. How much or little you water will depend on several factors including how much rainfall occurs and soil type and drainage. Pomegranates can stand very dry air conditions but, to produce good fruit, they need some moisture in the soil. In general, when growing on loose, sandy soil pomegranates will require more water and more fertilizer. When growing in heavier clay-based soils that retain more moisture plants won't require as much supplemental water. From flowering to harvest it's best to water only enough to keep the soil moist, but not constantly soggy.
NOTE: If for some reason you cannot water during dry periods don't worry too much, the plants should survive. Just don't expect as much fruit.
Pruning
Pruning can be important to increase yields and to keep your pomegranate bush or tree bushy and strong. I suggest pruning a pomegranate for at least the first three years of its life to get it to branch and put out new growth.
Pruning is best done in late winter or early spring, right when they begin to put out a few new leaves. At this time, prune off the tips of all the outer stems. Just clip off the outer four to six inches or less. On older, more well-established trees cut back a foot or two all over to make it branch and be bushier.
Feed immediately after pruning.
Pollination
Pomegranates are self-fruitful but the blossoms must be pollinated for it to bear fruit. If your fruit bearing pomegranate blooms but bears no fruit, this could be an indicator that there were no bees or other pollinating insects around when it bloomed. In order to become fruits the flowers must to be pollinated. Whether or not you see bees it's a good idea to use a sable paint brush to pollinate the flowers yourself. Just play like a bee and go from flower to flower spreading the pollen from one to another.
