Once you've decided their location, plant smaller, fast-growing vegetables around them. An interplanted garden does not resemble a traditional garden with all the vegetables planted in straight rows. Rather, interplanted gardens have a mosaic effect with paths oriented around the interplanted areas. Plants can be arranged to take advantage of contrasts in texture and color, making a garden more visually interesting. A common error in interplanting is crowding vegetable plants.
Crowded plants yield poorly and are more subject to diseases.
Consider the eventual harvest size of the vegetables you interplant, and space them so that at maturity they will just be touching each other. Make the interplanted area no wider than what you can easily reach across to keep from trampling plants. You also can avoid crowding by interplanting fast growing vegetables with slow growing vegetables, for example, radishes or lettuce with tomatoes. By the time the tomato plants are bearing, the lettuce or radishes will be harvested. Or some of the lettuce can be removed in May to make room to sow seed of winter squash.