Are Grapevines Self-Pollinating?

Self-Pollination

• Self-pollination in self-fertile plants such as grapes occurs when pollen grains from the anthers of the flower travel to the stigmas of the same flower or to other flowers on the same plant. This results in self-fertilization and leads to the eventual formation of the fruit. Self-pollinating plants do not need insects to carry the pollen to their flowers. Pollen is distributed through the vine primarily by wind. Fertilization occurs two to three days after flowers are pollinated. Ideal temperatures for production of pollen in grape flowers are warm 80-degree Fahrenheit days and 70-degree Fahrenheit nights.

Planting

• Plant grapevines in early spring, three to four weeks prior to the last frost. Select healthy 1-year-old plants and leave at least eight feet between American bunch type grape varieties and 10 or more feet between the more vigorous muscadine grapes. Reduce roots to 6 inches by trimming prior to planting. This helps to form feeder roots near the trunk. Make sure the planting hole is large enough to accommodate the root ball without crowding. Dig the hole as deep as the container in which the plants are growing. After planting, prune the vine to a single cane.

Site

• Select an area of full sun for growing grapes. The deep-rooted vines grow best in fertile, sandy loam preferably amended with organic matter. The vines also do well in well-drained, heavy clay and deep sand but require more frequent fertilization in these soils. The preferred soil pH is anywhere between 6.0 to 6.8. Apply a 4- to 6-inch layer of hardwood or softwood bark mulch around vines after planting.

Fertilization

• Fertilize the plants with nitrogen fertilizer except when growing in sandy soil, in which case other elements are also required on a regular basis. Use 1 oz. of ammonium nitrate right after growth resumes in spring, applying around the plant 10 to 12 inches away from the trunk base. Apply again after six weeks. In the second year, increase the amount to 4 oz. about a foot away from the trunk. Repeat every year. Use a balanced 10-10-10 fertilizer for plants growing in sandy soil.

Selection

• Select varieties that are best suited to the local growing conditions and climate. The intended use of the fruit, such as fresh, jams, jellies, processed, dried, wine or pies, is also a factor in selecting a certain variety. For instance the seedless, sweet varieties are best for raisins. Pay attention to the insect and disease resistance level of the plants, especially in regions with humid weather. Buy healthy plants from reputable sources and make sure plants are certified virus free. Use a magnifying glass to inspect for insects.