Pomegranates and muscadines

This week we focus on a couple of plant culture issues that have been brought to my attention.

First, there is a question concerning muscadines. I was asked by an avid gardener friend if it would be acceptable to prune muscadines in the fall rather than the usual time in February or early March. The short answer is yes, as long as it is done after a hard frost. Pruning muscadines or most other deciduous plants should be performed after they have gone into dormancy which, of course, occurs after a killing frost. At issue was the bleeding that inevitably accompanies pruning. Such bleeding (sap flow) is annoying but quite harmless and will most likely occur after a hard frost in the fall just as it does in the early winter.

Another question I received dealt with pomegranates. A reader reported that his 25-year old pomegranate bush bore many fruits, but many of them would fall off before reaching maturity. These immature fruits, as well as many of the fruits which remain on the bush and fully mature, develop soft, dark spots on the skin. Subsequently, the seeds in the area around these spots are rendered inedible.

Pomegranates are susceptible to rots caused by pathogens that develop during flowering and fruit development. Alternaria fruit rot (known as black heart) grows inside the fruits, causing them to become stunted and discolored. Rain and overly saturated soil cause the fungus to grow within the fruits at the time of flowering. Pathogens live on dead plant and fruit debris during the tree’s dormancy.

Aspergillus fruit rot is similar to Alternaria. This fungus grows inside the developing fruit after rainfall. Fruit skins can become off-color. While there is no known cure to this problem, removing and disposing infected fruit should help.

The most common problem with pomegranates is their failure to set fruit. They grow and flower well in most of the South, but tend to fruit poorly in our humid climate as compared to the warm, arid, less humid regions where they are particularly well adapted.

Inadequate sunlight and lack of pollination are two of the most common reasons that they do not set fruit. Planting two or more pomegranate plants close together will help, as cross-pollination increases fruit set.

Pomegranate flower color varies from scarlet-red to orange, yellow, white or variegated depending on the cultivar. Plants may be single or double-flowering with double flowers resembling carnation blossoms. In general, double-flowering cultivars produce few, if any, fruit.

Pomegranate plants grow at a moderate pace. They will flower sporadically the first year after planting into the landscape and may bear one or two fruits. More commonly they will begin to bear two to three years after planting.

If your plants do set fruit successfully, irrigating to provide even soil moisture will reduce fruit drop and prevent fruit splitting. Also, fertilizing plants in March and July with 1 pound of 10-10-10 for every three feet of plant height will aid in fruiting.

Although considered long-lived plants (some in Europe are over 200 years old), pomegranates’ vigor will decline after about 15 years.

Pomegranates are a challenging but worthwhile crop. Good luck with yours!

Tim Lewis is a Georgia Green Industry Association Certified Plant Professional, gardening writer, former Perry High School horticulture instructor, and former horticulturalist at Henderson Village and Houston Springs. He and his wife, Susan, own and operate Lewis Farms Nursery located on Hwy 26 two miles east of Elko, where he was born and raised. He can be reached at (478)954-1507 or timlewis1@windstream.net.