The so-called donut peach tree is a freestone heirloom variety with unusual flattened fruit. The tree grows as tall as 20 feet and produces fruit with a mild, yet sweet flavor. It tolerates below-zero temperatures and is appropriate for gardens in USDA climate zones 5 through 8. When you plant your tree, make sure the area receives full sun and has well-draining, mostly sandy soil. Also ensure that the mature tree will have an area at least 20 to 25 feet from other trees or buildings.
Prune bare root trees to an open center before you plant. This involves cutting the main central trunk to within 3 feet of ground level and pruning off all but two or three of the side branches to the trunk.
Fertilize newly planted trees with a plant food that is high in phosphorus to encourage strong roots. Phosphorus is indicated on fertilizer packages as the second number in the N-P-K reading. For example, a plant food having an N-P-K ratio of 10-20-10 is high in phosphorus. Follow label instructions for correct mixing and application. Fertilize mature trees in March and May, using about 1 lb. of a plant food with an N-P-K ratio of 10-10-10.
Water your peach tree by flooding the root zone once or twice each week during its active summer growing season. You can help keep the soil moist if you spread a thick, 3-inch layer of mulch around the trunk. Mulch made from tree bark is recommended.
Spray your donut peach tree during its winter dormant period in January and February with a copper fungicide to keep it safe from the disease called peach leaf curl.
Thin forming peaches about one month after your tree flowers to encourage better, large fruit and to prevent branches from breaking under the weight of too many peaches.
Harvest your donut peaches when they feel slightly soft: in most regions, donut peaches ripen in July. They will also have a reddish-orange color and reach about 3 inches in width.