Fertilizer and mulch
The first two or three years, each early spring, apply compost around the base of the vines. Grape vines grow vigorously and might need a nutrient boost each year. You may not have to do this as the vines mature; it all depends on what you observe. Do the vines look vigorous and healthy? Maybe you don't need any fertilizer.
Unlike many other plants, it is best not to mulch around the base of your vine as the mulch can keep the soil too cool. Grapevine roots like to be warm.
Weeding
Keep grass and other plants from growing under grapevines. This allows the soil to heat up early in the spring and maintain higher soil temperatures to encourage growth.
When plants grow under vines, the soil temperature stays cooler. With grapes, this will delay growth in the spring.
Keep the ground under the vines clear of other plants throughout the growing season by hoeing gently under the vines.
Doug the Cook