The doughnut peach tree (Prunus persica), also called the Stark Saturn, Peento or Saucer peach, is a fruit-bearing tree that grows up to 20 feet tall at maturity. It produces wide, flattened peaches that have a sweet, mild flavour. The peaches are shaped like doughnuts, and they have yellow and orange-red, fuzzless skin with white flesh. Doughnut peach trees grow best in zones 5 through 8, withstanding temperatures to -26 degrees Celsius. Select a planting site that’s in full sunlight and has deep, well-draining soil.
Water your doughnut peach tree deeply and evenly once or twice a week through the growing season, from spring until early autumn. Soak the soil to the root area. Spread a 3-inch layer of bark mulch around the base of the tree to keep weeds and grass at bay.
Spread a half-pound of 10-10-10 NPK (nitrogen-phosphorous-potassium) granular fertiliser over the tree’s root zone, about 12 inches from the trunk. Apply this feeding one week after planting the tree and again one month later.
Thin out the fruits on the tree to prevent limbs from breaking and to enhance the fruit quality. About one month after the flowers bloom, when the peaches are about the size of a quarter, remove some so the remaining fruit is spaced about 8 inches apart.
Spray the tree in late January with a Bordeaux mixture or similar copper-based fungicide to prevent peach leaf curl. Spray again in mid-February, coating the entire tree generously and following the directions on the label exactly. Be sure to spray the tree when it is not actively growing.
Prune away leaves that are shading the maturing peaches so they can receive plenty of sunlight. Harvest the peaches in July when they soften to the touch, are about 3 to 3½ inches wide and achieve a ripened, yellow and orange-red skin colour.
Prune the central leader stem so the tree is 26 to 30 inches tall immediately after planting it. Remove all lateral side branches from the tree.
Remove all upright shoots that develop inside the main lateral branches or around the trunk base during the first and second years. Cut away all diseased, damaged or low-growing branches.
Select the strongest branches on either side of the central trunk, at least one branch on the left side and one on the right during the summer. Prune all other lateral shoots from the main trunk and cut the central trunk back so it extends no more than 4 inches above the top branch.
Prune the lateral “scaffold” branches to about 18 inches long in March of the second year. In July, prune all growth from the branches, allowing only three stems to remain on each branch. Make sure two growths point upward and one points downward on each limb.
Prune subsequent years in April, after the flowers fade and the fruit begins to emerge, by removing the new shoots on the branches except for the shoot closest to the branch base and three or four of the healthiest, fruit-bearing shoots. Prune the peach tree again in early October to remove branches that produced fruit that year, leaving only the shoot closest to the base of the branch.
Feed your mature doughnut peach tree in March and again in May during the second and third years after planting with three quarters of a pound of 10-10-10 NPK fertiliser. When the peach tree is 4 to 10 years old, apply 454 or 907g of the granular fertiliser.
Don’t plant the tree in an outdoor area that’s prone to hard frosts. Select a sunny, southern-exposure site beside a wall for best protection from the cold.