Thompson seedless grapes are a popular variety grown in the hot climates in the western United States. This grape variety produces a sweet green grape that ripens in early fall. Thompson seedless grapes are smaller in size than the average grape and are eaten fresh or dried into raisins. Plant small rooted cuttings in the spring after there is no fear of frost. Plant vines with leaves present after May 30 for best results.
Select a planting location that offers full sunlight and the space for rows to run north-south. The soil must be well-draining to prevent root rot in the vines.
Test the soil pH with a home soil test kit. Thompson seedless grapes prefer a soil that has a basic pH of 7.0 to 8.0. Add limestone to soil to raise the pH level, if necessary.
Work the soil to a depth of 8 to 10 inches with a tiller. Mix compost into the soil to increase water drainage and nutrient value.
Plant the vines in rows at a distance of 5 feet apart. Gently pack the soil around the newly planted vines to hold them place.
Water the vines thoroughly after planting to stimulate root growth. Continue to water at ground level during the hot summer months to prevent the vines from drying. A mature plant will consume up to 7 gallons of water each day during fruit production in areas where the soil dries quickly.
Fertilize the grape vines in spring by working compost into the soil around the vines. Heavy fertilization is not required.
Thin the grape clusters by removing several clusters on each vine. This promotes larger berry growth on the remaining clusters.
Prune the grape vines during the winter dormant season by removing 75 to 90 percent of the past season's growth, as these vines will turn into woody vines. Fruit production occurs on 1-year-old vines.