Prune grapes to keep them healthy, fruitful

Grapes are pruned in January, but this is a chore that can be delayed up to March 15. If grapes are left unpruned, since they bear fruit on the new wood, they form their fruit farther and farther out from the main trunk each year that goes by. With time, the grapes are forming so far from the root system that they suffer from water stress and nutritional deficiencies. They become smaller in size and fewer in number.To avoid this, grapes are "renewed" each year through pruning. Doing this without seriously reducing production is a skill that should be demonstrated by someone who knows how to do it, but it is not that difficult.In the case of Muscadine grapes (our most commonly grown grape), it starts with training the grape so it has two permanent, 5- to 8-foot arms going in opposite directions down a heavy-duty, rust-proof wire 6 feet off the ground. This is all done the first year.The second year of growth will see shoots coming off these two permanent arms to bear grapes. At this time of year, all those shoots need to be cut back. Pruning the second season involves cutting off all shoots that come from the permanent arms of the vine to a point where they have only three to five buds. When you are done, the pruned vine will resemble antlers with lots of side points on them.In future years, you will do the same thing, but cut back only to where the previous season's stub was left. Old vines look quite strange, but they will keep bearing for more than 50 years if pruned and trained in this manner.If your Muscadine is growing on an arbor structure, you still need to renew it each year as well for good harvest. With arbors, we generally allow three main trunks/arms to come to the top of the arbor and then fan out. Each following year we keep these three main arms and only cut back to them, leaving three to five buds on each stub as before.This is confusing, so to learn more, go online to whatever search engine you use and type in Fruits & Nuts - UF/IFAS Extension: Solutions for Your Life. Then click on "Specific Fruits" and go to Muscadine grapes.Want someone to answer a specific plant question for you? Go online to clay.ifas.ufl.edu and under the heading "Horticulture" (left side of page), click on "Ask a Master Gardener" and a reply will be sent, plus a hyperlink to the appropriate University of Florida Fact Sheets. To speak to someone by phone, call 269-6355.Raymond Zerba is a University of Florida Clay County extension faculty member. To ask a question, call 269-6355 in Orange Park, 284-6355 in Green Cove Springs and Middleburg, or 473-3711 in Keystone Heights.