Home Garden Resource 

GRAPES

Grapes have the longest history of all the cultivated fruits and are among the most widely grown. The fruits are used to make juice, jellies, wine, and pies, and the leaves can be used in cooking. Grapes also are delicious eaten fresh, and their popularity has increased since the development of new seedless table grape cultivars for the Northeast and the Southeast.

Choosing Cultivars

Home gardeners can choose from a wide variety of grape cultivars, each differing in time of ripening, productivity, vigor, hardiness, fruit size, color, and flavor. The grapes most widely cultivated in the Northeast are derived primarily from Vitis labrusca and are referred to as American bunch grapes.
The following cultivars of this species produce well in much of New YorkState:
• Concord—the primary cultivar grown in the Northeast and the standard for hardiness.
• Niagara—the leading white grape cultivar, though it is not as hardy as Concord and is moderately susceptible to several grape diseases.
• Catawba—a late-ripening red cultivar that requires a favorable site and a long growing season to reach full maturity.
• Delaware—one of the highest-quality American bunch grapes, both for eating fresh and for making white wine. It ripens two weeks before Concord. The tender skin of the red berries, however, is subject to cracking, and the leaves are susceptible to fungal diseases. It requires a deep, fertile, well-drained soil for satisfactory vine growth.
• Ontario—the best of the early-ripening American cultivars. It produces white fruit. Vines are vigorous but not as hardy as those ofConcord.

Propagating Grape Vines

There are several ways to accomplish the propagation of grape vines. First is to prune your existing vine to develop the plant into a productive vine. As you prune, you can collect the prunings to use as cuttings to make more grape vines. As you cut the vines from the plant, make a slanted cut at the bottom of each vine. The plant "knows" up from down. You must put the cuttings into the propagation medium (potting soil or garden) with the bottom down and the top up. This is very important. If you make several cuttings from each pruned vine, make the top cut flat and then re-cut the next cutting to have a slanted cut at its base. Each cutting should be 4 to 8 inches long with several nodes (places where buds are located).

You can take some cuttings in the fall after the vines are dormant and all leaves have fallen. Do the major pruning in the late winter/early spring just before growth begins to avoid stimulating growth that can be killed by freezing temperatures. If you take cuttings in the fall, treat the base of the cutting with rooting hormone. Wrap the cuttings in moist (not soggy) sphagnum moss and store them in a sealed plastic bag in the refrigerator (not freezer) for at least 6 to 8 weeks. When you remove them from this cold storage (which simulates winter conditions and prepares them for growth), place them slanted end down (bottom down) into potting soil. You can put several cuttings in each pot if you wish. Place the pot and cuttings in a plastic bag to maintain humidity around them. (I prefer long narrow plastic bags such as those surrounding newspapers on rainy days.) Place them in a bright, warm location but not in direct sun. (Direct sun will create too much heat in the bag.) Growth should begin in a few weeks but roots may not develop immediately, so keep them in the bag. As growth begins, you can open the top of the bag slightly or, with a sharp pencil, punch some holes in the bag to admit fresh air. As the vines outgrow the bag, you can open it completely and even take the plants from the bag. If they begin wilting, put them back into the bags but gradually expose them to drier air. You can do the same thing in the spring as you do major pruning, but you won't need to treat them in the refrigerator. You can apply the rooting hormone and put them directly into the potting soil. After growth begins, you can cut some of the new tender growth and do the same thing. With the new softwood cuttings taken after growth begins, the humidity in the plastic bag is even more important. Without increased humidity, these cuttings with leaves will dry before roots can form.

If you have many cuttings after pruning the vine, you may want to try rooting some cuttings in water. In this case, just prepare the cuttings and place them into buckets or jars of water. 

Site Selection

A favorable site and climate is essential for successful grape growing. Specific requirements include:
• full sun.
• good air drainage.
• a 150-day frost-free growing season.
• minimum winter temperatures above –25 degrees F (USDA
Hardiness Zone 4b or warmer).
• 2,000 growing degree days above 50 degrees F (see www.hort.cornell.edu/gardening/weather/ for more information on growing degree days).
• soil that is neither excessively wet nor droughty.
Southern slopes or exposures protected by buildings or windbreaks are preferable to northern slopes and low ground, which tend to be cooler throughout the growing season and delay fruit ripening. Grapes tolerate a wide range of soil types and are not as sensitive to extremes in drainage as other fruit crops. Still, they are most successfully grown on deep, well-drained sandy
loams.

It’s important to choose cultivars that are well-matched to your site. You can grow grapes just about anywhere in New York, but not all varieties will survive (much less thrive) in every location. If you are in Zone 4 or Zone 5, be sure to carefully check nursery catalog information about hardiness. Cultivars vary in their susceptibility to winter injury. Temperatures below –15 degrees F can cause winter injury to all but the hardiest cultivars 

Planting and Early Care

Prepare the soil and adjust pH and nutrient levels as indicated by a soil test the season before planting (see “Before You Begin,” page 1). Plant purchased vines in spring as soon as the soil can be worked. Space vines a minimum of 8 feet apart both within and between rows, digging a hole large enough tospread out roots sufficiently.

After trimming away broken or excessively long roots, lay out the root system in the hole and cover completely with soil. Planting depth should be the same as in the nursery, usually about 2 to 3 inches above the root level. Remove all but the best single cane and tie it to a stake or the bottom wire of a trellis to hold it erect. This cane will become the trunk. It won’t grow straight without support.

After several weeks, buds should begin to grow. When the new shoots are about 10 inches long, remove all but the strongest as well as any other shoots that arise from the trunk. Also remove any flower clusters or side shoots as the single cane grows.

Fertilizing

Use no fertilizer the first year. In following years, apply 10-10-10 around the vines in early spring before growth begins:
Year 2: 2 ounces per vine
Year 3: 4 ounces per vine
Year 4: 8 ounces per vine
Year 5 and after: 16 ounces per vine

Commercial grape growers usually test the soil and conduct leaf analyses at least every three years to detect nutrient deficiencies or imbalances. Choose grape varieties that won’t suffer winter injury in your area.

Low Winter Temperature

(USDA Hardiness Zone) Suitable Varieties
0°F (Zone 7a) Almost any
-5°F (Zone 6b) Most northern vinifera
-10°F (Zone 6a) Hardy vinifera and moderately hardy hybrids
-15°F (Zone 5b) Hardy hybrids and most American varieties
<-15°F (Zone 5a and colder) Hardy American varieties

Stake canes at planting. They won’t grow straight without support.

 

Getting Grapes Ready, Ask The Expert

 

Hi Patty,

I have several grape vines that grow successfully here on Grand Island, which is known for it's clay soil.

SOIL AND SITE: Good air circulation, sun exposure and a soil that is well drained are desirable for quality crops of grapes. Air circulation is best if the location has a gentle slope; avoid low frosty pockets. Plant the vines away from trees so that they will
receive full sunshine. Grapes are not as particular to soils as other fruit crops; as long as the soil is best; rich soils stimulate excessive vine growth at the expense of fruit quality. Grapes require a soil pH of 5.5 to 7.0.

You can find a brochure to growing grapes in New York, available in a downloadable pdf file at Cornell Cooperative Extension at http://www.gardening.cornell.edu/fruit/index.html

Good luck to you.

The WNY Alive Garden Resource Team
www.wnyalive.com