Issue: April 7, 2007
I hope you can help us maintain our pomegranate trees. They are 8-10 ft. high and over 25 years old. Two are fruit bearing and all are in dire need of pruning. After pruning, new growth always quickly and aggressively grow back from where the cuts were made undoing most of the effect of the pruning. The trees have decreased in blooms. I think this is because the tree needs more light and air in its center. It has also received plenty of 20-20-20 the last two years. I intend to ask the spray man not to use 20-20-20 again.
Can we prune differently to reduce the aggressive regrowth, or are we pruning at the wrong time? We usually prune after tree is green and before blossoming begins.
We look forward to your columns and hope the TV series returns. Thank you for sharing your knowledge and appreciation for gardens and related 'things'.
Thank you for your kind words and your interest in the garden column and television show.
The pomegranate produces flowers on new growth, so it can be pruned in the dormant season. Prune from fall to late winter before growth resumes. When beginning with a new plant, the pomegranate is developed to be a shrub-like tree with a trunk about one foot high. At this level, four to five branches are encouraged to form so that they are uniformly distributed around this short trunk. The result is that the trunk is hidden and the plant looks like a shrub. These branches should be trimmed back severely for the first three years. This is to develop a strong branching system so that there will be maximum fruit production. Flowers and fruit are developed from buds at the ends of new growth, so pruning is done in a manner to develop many smaller branches that will produce this fruiting growth. After the basic structure of the pomegranate plant has been developed, annual pruning should be reduced to remove only dead shoots and the vigorous water sprouts that you have described as a result of pruning.
Your pomegranate may not have this form, but that should not be a problem. You can develop an adequate structure with what you have. Your pruning will be like the pruning given these tree/shrub plants after the basic structure is formed. You may find that it is useful to remove some of the weak, interior branches completely. This will remove the portion that does not receive enough light. After thinning the interior to the basic four to five major branches, you can prune back one or two branches each year to develop the smaller fruit supporting branches. If the vigorous water sprouts develop following pruning and they are located where you want a branch, prune them back severely. Otherwise, remove it completely. Prune these water sprouts as soon as they appear following pruning. Don't wait until the next year. Prune only minimally, as described above, for established pomegranates.
I congratulate you for growing pomegranates. Although they will not grow well in colder parts of New Mexico, they will grow in much of the state. In colder areas, they can be grown in protected microclimates. They have attractive flowers and edible fruits considered to be a very healthy fruit for eating.
Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: firstname.lastname@example.org, office: 505-865-7340, ext. 113.
Please copy your County Extension Agent and indicate your county of residence when you submit your question!