The expert recommendation for planting peach trees is in rows 20 feet apart to prevents the spread of disease and allow each tree the adequate amount of sunlight to ripen the fruit. Professional farmers and orchard growers follow this guideline when planting peach orchards.
Number and Variety of Trees
Following the rule of 20 feet may depend on the space you have and how many trees you're planting. If space is at a premium, you might consider dwarf varieties of peaches that require only 12 to 15 feet of space. Dwarf peaches do not bear as much fruit per tree, however, since the trees themselves are smaller.
Full-sized peach trees need at least 18 feet of space in any direction to truly thrive and produce quality fruit, although the ideal is 20 feet. For yards with restricted available space, dwarf varieties are an alternative. Consider both the desired number of trees and the space available in order to choose between full-sized and dwarf varieties.