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Top 10 Questions About Grapevines

Here at Gardening Know
we get lots of questions, and our goal is to provide answers to
those inquiries to the best of our knowledge. Growing grapes
in the landscape is a popular endeavor for many gardeners, and one that
includes many issues. As a result, we receive a number of questions about grapevines
in the garden
. Here are the top ten.

1. What type of soil is best for growing grapevines?

prefer a well-draining sandy loam with a pH of 5.5-6.5. That
said, grapes are fairly tolerant of their soil conditions provided they are neither
too alkaline or too acidic, have sufficient organic content and are

2. Can you plant just one grapevine or do you need two?

Almost all commercially produced and grown grapes are self-pollinating.
This means that they do not require another grape to set fruit. Wild grapes, on
the other hand, usually require a male and a female plant to produce grapes. If
you have the space though, plant two just for variety.

3. How to prune grapevines?

should always be pruned
during their dormant period in the winter. In order
to promote fruiting, be brave and prune hard. Be sure to cut off as much of the
old wood as possible, which will, in turn, encourage production of new shoots
and vines upon which the fruit is produced. When pruning grapes that require
winter protection, the goal is to prune into one horizontal trunk that can
easily be removed from the support structure. Otherwise, remove all growth
except new fruiting canes and renewal spurs. Select a branch and cut it back
3-4 feet (around a meter), leaving at least a two-bud renewal spur. Tie this
cane to the support and remove all other canes. At the end of the growing
season, cut off the old trunk just below the renewal cane.

4. What to use to fertilize your grapevines?

Grapes have a deeply growing root
system and, as a result, unless your soil is very poor, usually require very
little additional fertilizer. The only way to really be sure is to do a soil
test; grapes like a pH of 5.5-7.0, so amend accordingly. Thereafter, give the
vine a light fertilization with an all-purpose 10-10-10 food at the rate of no
more than ¼ pound (113 g.) applied in a circle 4 feet away from each vine. If
you would rather use manure, apply 5-10 pounds (2-4.5 kg.) of poultry or rabbit
or 5-20 pounds (2-9kg.) of steer or cow manure per vine. Urea, ammonium nitrate
and ammonium sulfate can also be used to fertilize the grape after the vine has
bloomed. Fertilize
just when buds emerge in the spring.

5. How soon after planting will you have grapes to harvest?

Grapevines do not usually produce their first year, although
it depends on how old the vine was when purchased. Generally, grapes begin
producing in their second year but these should be snipped off to allow the vine
to focus on strengthening its root system. By the third year, a healthy vine
should be producing grapes for harvesting.

6. How do I get vines to produce grapes?

A grapevine that is not producing could be the result of
several of factors. It could be that the soil pH doesn’t suit the vine; grapes
like a pH of 5.5-7.0. They also do not like soil that doesn’t drain well or has
a surfeit of nitrogen. Do a soil test and then amend the soil if necessary. It
may be that the vine does not get sufficient light. Pruning hard will go a long
way to giving the vine access to more light and a hard prune actually
encourages growth. Most hard pruning should be done every winter when the plant
is dormant, but some cultivars such as Concord, Crimson Seedless, and Thompson
seedless are cane pruned in the spring and early summer. Most grapes are
self-pollinated, but there are a few that require a partner or they will not
produce. If your grape is a Riverbank grape or Muscadine,
it needs partner in order to produce grapes.

7. How do I move my grapevine to another location?

Grapevines have deep tenacious roots, so if you need to move
the vine, you will either need a backhoe or a strong back and a willingness to
sweat. If you are up for it, the best time to transplant
a grapevine
is in the fall or early spring. Cut the vine back to 8 inches (20
cm.) from the ground. Dig around the trunk to locate the peripheral roots and
then start digging them free from the soil. Once these outer roots have been
freed, dig a deep vertical trench around the vine and lever it from the earth.
Move the vine to a hole that is twice as wide as the root system. Loosen the
soil at the bottom of the hole to accommodate the roots and then fill in. Water
the vine frequently as it establishes.

8. How do treat black rot of grapes?

rot of grapes
should be treated between bud break until around four weeks
after bloom. Use Captan or Myclobutanil fungicides. Otherwise, prevention is
the best management option. Remove any mummy grapes and all grape detritus from
the ground in the fall. Prune out any afflicted vines and don’t be afraid to
prune heavily. In the spring, if any lesions pop up, remove them ASAP and begin
fungicide applications.

9. How grow grapes in a pot?

grow quite well in containers
if you follow a few guidelines. First of all,
you need a container that is at least 15 gallons with drainage holes. The
container can be made of almost anything but keep in mind that some materials
absorb heat and might make the roots of the plant too hot. Next, you need a
sturdy trellis or other support. Now you just need to plant your grape. Grapes
are tolerant of most soil types but prefer a well-draining, sandy loam with a
pH of 5.5-6.5. Grapes do not need additional fertilizer, but if you do decide
to feed the vine, do so with a low nitrogen food. Keep the container
consistently moist.

10. How to winterize grapevines?

winter protection
depends on your USDA zone. Some areas can get away with
mounding 8 inches (20 cm.) of snow over the vines, while colder regions need to
add insulating mulch like straw or shredded cornstalks to protect the vines. If
your area gets cold but doesn’t snow, the vines should be covered more deeply,
say with a foot or two of soil. Some gardeners go to extremes and actually plant
the vine in a deep trench. As the plant grows, more soil is added. Others use a
shallow trench and the dormant vines are removed from their supports, wrapped
in old blankets or burlap and then placed into a slightly sloped trench lined
with sand. A second layer of protective covering place atop the vines along
with black plastic or insulating fabric and is then secured with soil or rocks.

We all have questions now and then, whether long-time
gardeners or those just starting out. So if you have a gardening question, get a
gardening answer
. We’re always here to help.

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