3. Space smartly.
To get the maximum yields from each bed, pay attention to how you arrange your plants. Avoid planting in square patterns or rows. Instead, stagger the plants by planting in triangles. By doing so, you can fit 10 to 14 percent more plants in each bed.
Just be careful not to space your plants too tightly. Some plants won’t reach their full size—or yield—when crowded. For instance, when one researcher increased the spacing between romaine lettuces from 8 to 10 inches, the harvest weight per plant doubled. (Remember that weight yield per square foot is more important than the number of plants per square foot.)
Overly tight spacing can also stress plants, making them more susceptible to diseases and insect attack.
4. Grow up.
No matter how small your garden, you can grow more by going vertical. Grow space-hungry vining crops—such as tomatoes, pole beans, peas, squash, melons, cukes, and so on—straight up, supported by trellises, fences, cages, or stakes.
Growing vegetables vertically also saves time. Harvest and maintenance go faster because you can see exactly where the fruits are. And upward-bound plants are less likely to be hit by fungal diseases thanks to the improved air circulation around the foliage.
Try growing vining crops on trellises along one side of raised beds, using sturdy end posts with nylon mesh netting or string in between to provide a climbing surface. Tie the growing vines to the trellis. But don’t worry about securing heavy fruits—even squash and melons will develop thicker stems for support.
5. Mix it up.
Interplanting compatible crops saves space, too. Consider the classic Native American combination, the “three sisters”—corn, beans, and squash. Sturdy cornstalks support the pole beans, while squash grows freely on the ground below, shading out competing weeds. This combination works because the crops are compatible. Other compatible combinations include tomatoes, basil, and onions; leaf lettuce and peas or brassicas; carrots, onions, and radishes; and beets and celery.