Vegetables should be planted away from buildings, tress, and other objects that shade the garden. If part of your garden is in the shade make it work for you- plant vegetables that do well in shade like lettuce, spinach and other related veggies. Don't plant your garden near trees their roots can compete with the vegetables for food and nutrients. Place the garden on high ground rather than in a depression at the base of the hill. Low spots warm up slowly in the spring.
High ground allows vegetables to escape borderline freezes.
Locate the garden away from low or soggy areas where water stands in puddles after rains. Use contour rows or terraces on hillside gardens. Rows run across a slope help catch the rain. Avoid windy locations. Do not plant your gardens in windy locations.