Vegetable planting distances vary from crop to crop, and are printed on the backs of seed packets. For gardeners purchasing transplants from garden centers, planting distances are printed on the tags stuck in each vegetable pot. Heeding this information ensures the best possible start to a vegetable garden, no matter what is planted.
Planting vegetable crops the correct distance from one another ensures that all plants will have adequate access to what they need to grow. Nutrients, water and sun are necessary to all vegetable plants, no matter the crop. Vegetables that do not get the correct amounts of these things because they are planted too closely may be stunted, or may not grow at all.
Vegetables planted a suitable distance from one another develop normally. While this alone does not ensure a successful crop, it is one less worry for the gardener. The gardener can then concern herself with other things, such as pest and disease control. Vegetables planted the correct distance from one another may help the gardener in that regard as well. As with people, plants that are strong and healthy are better able to combat diseases that may occur.
Overseeding and Thinning
Gardeners who choose to direct-seed their gardens (plant seed directly in the ground, as opposed to using transplants) should overseed initially. This helps to account for any seeds that do not sprout. When seeds have sprouted, gardeners can then choose from the healthiest specimens and thin out all weaker seedlings. In this case, the planting distance for vegetables does not come into play until seedling thinning takes place.
When thinking about vegetable planting distances, it is important to consider not only the parts of the plants above the ground, but the root systems as well. Tomato root systems, for example, can grow to more than 2 feet across per plant. Root vegetables require special attention to space requirements because the vegetables they produce grow underground. Foliage above the ground may not necessarily tell the whole story about the massive amount of potatoes a gardener's plants are producing below ground.
It is tempting when gardening to let all seedlings that have successfully sprouted grow larger. Gardeners who may be ruthless when weeding may have soft spots for the seedlings they find that they must thin out. However, it is in the greater interest of the strongest seedlings to thin them sooner rather than later, preferably before the second set of leaves has appeared on the seedlings. This ensures that the strongest seedlings do not have unnecessary competition for nutrients, water and sunlight. As vegetables grow larger, the foliage of the tallest plants will shade smaller plants if they are grown too close together. If they are vegetables that tolerate shade, such as lettuces, the results may be acceptable. If sun-loving plants are shaded, however, they will be stunted or may possibly even die altogether.