Though tree spacing is largely a personal choice in home gardens, proper spacing helps pine trees maintain health as they grow. Gardeners should take into consideration the type of pine tree they are planting, as larger trees will require more space than smaller trees as they mature.
Proper spacing ensures that every pine tree receives the nutrients it needs from the soil, with minimal competition. This is especially true when providing plenty of breathing room between trees. On the other hand, planting pines closer together helps them grow in a more compact form, without requiring excessive pruning.
Large pine trees, such as the Ponderosa pine, require 15 to 20 feet of space between each tree, according to horticulturalist Ron Smith at the North Dakota State University website. Young trees may seem far apart in this configuration, but they will fill the gaps as they mature.
When planting fields of pine trees, gardeners can choose between low density planting and high density planting. Wide spacing allows pines to grow outwards for a rotund appearance, while tight spacing -- such as 7 to 10 feet between trees -- keeps pines slimmer.