Planting
Plant vines eight feet apart in rows that are eight to ten feet apart. Rows should run at right angles to the slope. In an area that normally is very windy, plant in the direction of the wind to minimize damage. Purchase one or two-year-old vines. First grade, one-year-old vines are preferable. Vines should be planted at about the depth they were grown in the nursery. Grafted vines should be planted with the graft union about two inches above ground level. Roots should be spread out in the planting hole. After the vine is planted, remove all but the most vigorous cane, and out back this cane to one or two buds.
Soil Preparation
Grapes prefer deep, well-drained, sandy, or gravelly loam soils. Excessively wet or dry soils should be avoided. Adequate soil preparation is essential since grapes are deep-rooted, long-lived plants. Work soil to remove perennial weeds, and add humus (peat moss, compost, aged manure) to improve soil quality. Select sites with full sunlight and good drainage – preferably a hillside that faces south. Frost-free sites are essential.
Lime and Fertilizer Requirements
Before Planting – Grapes prefer acid soils with a pH between 5.0 and 5.5. Thoroughly work in sulfur or ammonium sulfate (or similar material) as suggested by soil test results before planting. Well-aged manure at two to five bushels per 100 square foot can also be worked into the soil before planting.
After Vines are Planted – Commercial fertilizers are generally not necessary the year vines have been planted. Four to six ounces of 5-10-10 may be applied to poorly growing, newly planted vines.
When Vines are Bearing – Each year, double the rate listed above until plants reach maturity. Three to four pounds of5-10-10 (or equivalent) per vine per year is the recommended rate for mature vines.
Mulching
Mulching an area about two feet wide with grass clippings, straw, or other suitable material will help keep young vines free from competing weeds and will also help to conserve soil moisture. To properly prune a vine, you should know something about its growth and fruiting habits. The vines should be pruned during the dormant season, preferably in March. Some things you must keep in mind are:
- The fruit is borne on shoots rising from one-year-old wood (canes).
- The most productive canes are about pencil thickness (0.25 inch to 0.30 inch) and have an internodal length of five to eight inches between the fifth and sixth nodes or buds.
- The most productive buds are in the mid-portion of the cane; therefore, it is best to leave canes of 8 to 16 buds in length. Thin canes should carry fewer buds than thicker canes.
- To keep the fruiting wood close to the main trunk, leave one or two renewal spurs on or near each arm. Prune the vine so you will maintain a balance between vegetative growth and fruit productions. Where a vine is underprunned, (too many buds left) the fine will produce many small clusters of small grapes that may fail to ripen properly. If the vine is overprunned, (too few buds left) the yield will be low and the vegetative growth excessive. To “balance prune” a vine, the number of buds left is adjusted according to the amount of one-year-old wood removed in pruning.
The following is a procedure you can use for balance pruning a vine:
Estimate the weight of the one-year-old wood that is to be removed. If the estimate were two pounds, a Concordvine would be pruned in 40 buds or nodes (30+10). If the estimate was three pounds, 50 buds would be retained (30+10+10).
You then select four to six canes to be retained for fruiting, but leave an extra number of buds in case you have underestimated the vine’s growth.
Prune the vine. Weigh the one-year-old wood and adjust the number of canes and buds to be retained to the weight of the wood removed. After pruning a number of vines, you may be able to balance prune without weighing or counting.
Suggested pruning severity for balanced pruning of mature vigorous vines of some major varieties.