Proper Spacing and Plant Density
Raised beds often tempt gardeners to cram in as many plants as possible, but overcrowding can invite fungal diseases and reduce yields. For example, tomatoes from the Andes region benefit from 24–30 inches between plants, allowing good air circulation and sun exposure. Cucumbers need roughly 12–18 inches, depending on whether they’re bush or vining types, to prevent dense, humid clusters of foliage where powdery mildew can thrive. I once lost half my slicing cucumber crop to mildew because I planted them too close together; re-spacing subsequent rows helped me avoid that issue entirely!
Leafy greens like lettuce or spinach—both originally from Mediterranean climates—can be planted more densely (about 6–8 inches apart) since they don’t form tall, woody stems. However, stagger these in two rows down a 4-foot-wide bed to maximize sun penetration and airflow. I love planting alternating rows of kale (native to Turkey and southeastern Europe) with spinach, creating a patchwork of greenery that reduces weed pressure and fosters beneficial insect movement. Proper spacing not only boosts vegetable health but also lets pollinators, like bumblebees for squash blossoms or solitary bees for pepper flowers, easily access blooms without obstruction!