Grapes change color before they reach peak sweetness. They need the warm sun to finish ripening completely. If your late-season grapes seem slow to ripen, remove a few of the large leaves that may be shading them so the sunlight can reach the clusters.
Clean up dropped leaves, pruned vines and other debris. Debris harbors pests and diseases, and good garden sanitation will help keep your grape vines healthy.
Take cuttings of dormant grape vines in late fall. Pot them immediately. Protect the rooting vines from freezing.
Protect a tender grape variety by pruning the vine to a single trunk. Loosen the vine from the support structure. Lay the vine along the ground, and cover it with 6 to 8 inches of soil or mulch. Remove the mulch when the weather has settled in the spring, and lift the vine up to the support structure.