Bulletin #2068, Growing Peaches in Maine

By Renae Moran, Extension Tree Fruit Specialist, University of Maine Cooperative Extension

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Table of Contents:

Peaches are a highly desired fruit in Maine. Peach trees in Maine have a short life expectancy of about 7 years, but severely cold temperatures can kill trees at any age. Because they usually bloom in mid-May, they often escape spring frost damage to blossoms. Nectarines are fuzz-less peaches and consequently have the same cultural requirements. However, they are not as hardy or disease-resistant as peaches and may pose more of a challenge to the home gardener.

When growing peaches, there are some considerations in selecting varieties and cultural practices that can increase lifespan and fruitfulness.

peach blossoms — **Figure 1.** Attractiveness of the flowers may be a reason for selecting certain peach varieties.

Selecting Varieties

When selecting peach varieties (Table 1) to plant, consider winter hardiness and disease resistance to prevent long-term problems, in addition to fruit quality, fruit color and shape, and ripening date. Ripening date is also an important factor in selecting varieties. To extend the harvest, select varieties that ripen at different times. In Maine, early ripening peaches begin to ripen at the end of July. With late-ripening peaches, the harvest can extend into late September. Some varieties of peach have more showy bloom than others like Redhaven and Reliance (Fig. 1). Autumnstar, Salish, Saturn, TangOs and Veteran are a few varieties that have attractive blossoms.

There are several types of cultivated peaches that vary in eating quality and how they are used. Most peach varieties have a melting flesh that makes them great for eating fresh, but this type is more likely to bruise when fully ripe. Nonmelting or firm-flesh types have a denser flesh that makes them useful for canning. With this type, the flesh remains firm until the peach is fully ripe. Some varieties have a flattened shape and are called donut or saucer peaches (Fig. 2). Peaches also vary in their flesh color, with yellow-orange being the most common, but some have white, red or purple flesh (Fig. 3). The purple color in some peach varieties comes from a common type of plant pigment called anthocyanin. This is the same type of pigment found in other fruits such as blueberry and cherry.

Early ripening peaches have the tendency for split pit, a condition where the pit splits open before harvest tearing open the peach flesh (Fig. 4). Once this happens, the fruit becomes highly prone to brown rot. The condition is not common in later-ripening varieties.

Fig. 3. A peach with white and purple flesh.

Fig. 4. A peach with a pit that has split open and torn the skin at the stem end.

Table 1. Important traits of common peach varieties


Type	Variety	Flower bud cold hardiness	Ripening date	Leaf curl resistance	Fruit size	Fruit quality
Yellow flesh	Autumnstar*	poor	mid-September	unknown	large	good
	Belle of Georgia	fair	September	poor	medium
	Blazingstar*	good	mid-August	unknown	medium	good
	Canadian Harmony	good	mid-September	fair	medium
	Contender*	good	mid-September	fair	medium	good
	Coralstar*	good	late-August	fair	large	good
	Cresthaven	best	mid-September	unknown	medium
	Desiree*	poor	early-August	unknown	small to medium	excellent
	Elberta	fair	late-September	good	large
	Frost	good	early-September	good	small
	Harken*	fair	mid-September	good	medium	fair
	Harrow Beauty*	fair	mid-September	fair	large	good
	Garnet Beauty*	good	early-August	good	small	fair
	Glowingstar*	good	early-September	unknown	medium	excellent
	Madison	good	late-September	unknown	large	fair
	Messina*	good	mid-September	unknown	small	excellent
	PF 8 Ball*	fair	mid-August	unknown	medium	good
	PF Lucky 13*	good	mid-August	unknown	medium	good
	PF 15A*	good	mid-August	unknown	medium	good
	PF 17*	good	late-August	unknown	medium	fair
	PF 23*	poor	early-September	unknown	small	fair
	Reliance*	good	mid-August	poor	small	fair
	Redhaven*	good	late-August	fair	medium	good
	Starfire*	good	early-September	fair	medium	fair
	Summer Serenade*	poor	mid-August	unknown	small	excellent
	Tiana*	unknown	mid-September	unknown	medium	good
White Flesh	Blushingstar*	poor	early-September	unknown	medium	good
	July Rose*	good	mid-August	unknown	small	good
	Salish*	fair	mid-September	good	small	fair
Flat (Donut)	BuenOsII*	good	mid-August	unknown	small	good
	Saturn	unknown	late-August	fair	small	good
	TangOs*	good	mid-August	unknown	small	excellent

* Indicates a variety that has been evaluated at the Univ. of Maine’s Highmoor Farm in Monmouth, ME (USDA hardiness zone 5b).

** Evaluations for leaf curl resistance are based on observations and research conducted elsewhere.

Winter Hardiness

Lack of winter hardiness is the biggest limitation to growing peaches in Maine. Peaches are too tender to survive winters in the northern half of the state and are short-lived in central Maine. The life expectancy of peach trees depends on the frequency of severely cold temperatures, but can be longer or shorter than the average, depending on the occurrence of winter temperatures below -20 °F, and the hardiness of the variety. Flower buds lack the hardiness to survive temperatures that commonly occur in winter, so trees bear fruit less consistently than apple trees. Expect to have fewer fruit when winter temperatures dip below -10 °F. Reliance, Redhaven and Cresthaven have good flower bud hardiness. Some newer varieties with good bud hardiness are Glowingstar, PF 15A and the donut peach BuenOsII.

Planting in an ideal site or location can reduce the chance of winter injury. Peach trees will perform better in full sun and well-drained soil. Sites with good air drainage reduce the chance of dangerously cold temperatures. Air drainage allows cold air to move out of the orchard and into the lower elevation, so the site is less likely to have the coldest temperatures during an inversion freeze or frost.

Site Selection

In selecting a site to plant peach trees, higher elevations are preferable to lower ground or areas that are protected from the wind because they tend to be warmer on the coldest winter and spring mornings when a radiational freeze creates an inversion of warm and cold air. This type of weather event occurs during calm, clear nights when the lack of wind allows cold air to move downhill and warmer air to remain at higher elevations, leading to the inversion of warm and cold air. Ideal sites occur on sloping land that is not surrounded by dense woodlots.

Peaches need full sun for maximum winter hardiness and for the development of flower buds. They thrive in well-drained soil with a pH in the range of 6.0–7.0. Prior to planting, have the soil tested and correct any pH or nutrient problems. Soil test kits are available at Cooperative Extension offices. Where soil pH is too low, a soil test can determine how much lime is needed to adjust it. Most soils are sufficiently fertile to take care of the nutritional needs of peach trees. Infertile or sandy soils will benefit from some addition of organic matter and application of conservative rates of fertilizer.

Planting

Peach trees can be purchased from specialty nurseries that generally ship bare-root trees in spring or from garden stores that offer potted trees all season. Specialty nurseries will ship bare-root trees in the springtime and provide a wide selection of varieties. Bare-root trees should be inspected on arrival. If roots are dry, they should be moistened right away. For the best outcome, they should be planted soon after arrival. Garden stores offer trees in pots, allowing for an inspection of the tree before purchase. Avoid buying trees with pot-bound root systems, but if this is not possible, loosen or cut some of the roots prior to planting so that water can soak into the root ball.

The traditional spacing for peach trees is 15 feet apart, but with annual pruning, closer spacing is possible, particularly in Maine’s cold climate that limits tree growth. Where space is limited, trees can be planted as close as 8 feet, but annual pruning will be needed to keep trees from growing into each other. For tips on how to prune trees at planting, see the section on pruning.

Fig. 5. The tap root of a peach tree. — **Figure 5.** The tap root of a peach tree.

The best time to plant is early May, but June is also suitable. It is best to add only soil to the planting hole. If compost is added, it should be thoroughly mixed with the soil prior to planting. Peach trees may have a large root system with a long tap root (Fig. 5). Water trees with about three gallons of water after planting. Fertilizer may be spread on the ground after planting but wait two weeks to one month from planting so that the soil will settle and prevent fertilizer from moving into the soil and coming into contact with roots. For newly planted trees the rate is 8 ounces per tree of 10-10-10 balanced granular fertilizer.

Water trees with 2–5 gallons during dry spells or if rainfall has not occurred in the previous 1–2 weeks. Apply wood chip or bark mulch in an even layer 3–4 inches deep to inhibit competing weeds. Avoid other types of mulch because they can encourage root rot or vole feeding on the lower trunk.

Pollination

The majority of peach varieties are self-fruitful and do not require another variety for cross-pollination. This allows gardeners to plant just one tree or a solid block of one variety. Despite this, bees actively visiting blossoms will aid in pollination and ‘fruit set’, the stage of fruitlet growth when pollination and fertilization of the undeveloped seed is complete. Bees and other pollinating insects carry pollen to the pistil, which is the flower part that houses the seed and grows into the fruit. When cold, rainy weather occurs throughout the bloom phase, lack of bee activity can reduce pollination and subsequent yield.

Fruit Thinning

When winter temperatures are mild and most of the flower buds remain alive into spring, the tree will produce an excessive amount of fruit. By harvest time, the weight of all these peaches will strain the branches, which could lead to limb breakage or trees splitting in half. An excessive number of peaches will lead to small fruit size and bland-tasting fruit at harvest. In addition, the large number of fruit takes energy away from the rest of the tree and leads to less flowering in the following season.

To reduce the ‘crop load’, some of the fruit should be removed in mid to late June, but fruit thinning in July will also be beneficial. Thinning fruit early in their development will benefit the tree more than removing them close to harvest time. Thin fruit so that the remaining ones are spaced about 6–8 inches apart (Fig. 6). In some years, this may entail the removal of more fruit than what is eventually kept. To reduce brown rot disease, clean up fruit from underneath the tree and compost it in a location outside the orchard. An additional way to reduce the severity of brown rot is to thin fruit when they are not yet dime-size so that the thinned fruit will decompose before harvest. Thinned fruit that is infected with brown rot will enable the fungus to spread to healthy fruit. Blossoms can also be removed soon after bloom to get a head start on fruit thinning (Fig. 7), particularly when they occur in abundance.

Figure 7. A peach shoot before (left) and after bloom (right) thinning. — **Figure 7.** A peach shoot before (left) and after bloom (right) thinning.

Common Diseases

Peaches and nectarines are susceptible to several diseases that infect shoots, blossoms, fruit, and wood. Selection of resistant or tolerant varieties is the most effective method of prevention, but no variety is resistant to all diseases.

Brown rot is a severe disease of peach, and no variety is completely resistant. Wet weather favors infection by this fungal disease, so expect more severe outbreaks when rainfall occurs during bloom and as fruit ripens. The brown rot fungus infects blossoms and fruit, but in severe cases, will also infect shoots (Fig. 8). Fruit infections begin as a small, water-soaked spot on the surface of the fruit, but can very rapidly grow to overtake the entire fruit. After infection, flowers and fruit turn brown and develop spores that continue to spread the disease. Fruit eventually shrivels as they dry in late summer, which allows them to persist on tree branches where they remain into the next growing season (Fig. 9). Such ‘mummies’ should be removed from the tree before the start of growth in spring. Another method to reduce the spread of the disease is to conduct any fruit thinning early in the season, early June, so that fruit that has been removed and lies on the ground beneath trees can decompose before harvest. The brown rot fungus can also cause small cankers on shoots, which serve as a source of spread in springtime.

Figure 8. A fruit and neighboring shoot infected with brown rot.

Figure 9. A peach ‘mummy’ fruit that had shriveled and dried following infection by the brown rot fungus.

Peach leaf curl occurs in the springtime as buds begin to grow. Rainfall at this time favors the fungus, which invades buds and causes the subsequent puckering and yellowing of the foliage in late spring (Fig. 10). Infected foliage will eventually drop by summer. As the season progresses, shoots outgrow the disease and have a normal appearance. Fruit infection is uncommon in Maine. Although unsightly, peach leaf curl has little or no impact on the health of the tree when symptoms are mild but can lead to poor flower bud development and shoot dieback in winter after severe cases.

Few varieties are resistant, but several are highly susceptible and should be planted with caution. Resistance is reported to be greatest in Avalon Pride, Autumn Rose, and Frost.

Effective treatment with fungicides is very time-dependent because once the buds are infected in early spring, the disease cannot be prevented that season. The fungus overwinters on the tree, where it is ready to infect leaf buds by the time they begin to swell with warming temperatures. When it rains during the bud swell phase, the fungus will easily infect the buds. Therefore, dry weather during this time will often lead to seasons with a low occurrence of disease. Prior to wet weather, a copper fungicide can be applied to prevent infections. In the fall, after leaves have dropped, or in spring before ‘bud break’, are the effective times for applying a fungicide.

Figure 10. Peach leaves infected with peach leaf curl in spring (left) and later in summer (right). — **Figure 10.** Peach leaves infected with peach leaf curl in spring (left) and later in summer (right).

Cankers on peach trees are common and occur after winter injury. Branches with cankers can be removed with pruning (Fig. 11), but when cankers occur on the trunk (Fig. 12), removal becomes difficult without damaging the tree. Oozing is a sign of winter injury or disease, but in many cases, the tree eventually recovers from the injury, so tree removal should not be the first option unless the tree is obviously dead.

Figure 11. Branches with diseased cankers should be removed during pruning. — **Figure 11.** Branches with diseased cankers should be removed during pruning.

Bacterial canker occurs on the limbs and trunk, but the same bacteria cause leaf spotting that shows up as tiny holes in the foliage in summer. Spread and infection are favored by wet weather. Inner bark turns brown and may have an odor. Weak trees are more susceptible than healthy trees, so planting in good sites, annual pruning, fruit thinning, and irrigation during dry spells will reduce the chance of infection.

Peach scab is caused by a fungus that infects the fruit skin in summer and results in small spots on the peel (Fig. 13). In years with frequent rain during early fruit growth, the disease can be severe. Both fruit and shoots can become infected, but the disease is generally more severe on fruit. Small, circular spots appear in early summer and are usually more prevalent at the stem end of the fruit. Nectarines may have larger spots than peaches. As the spots enlarge and grow into each other, the skin can no longer stretch as the fruits increase in size, so skin cracking ensues.

Figure 12. Cankers occur on the trunk following winter injury. In some cases, surrounding tissues heal. In severe cases, the trunk becomes invaded by bacteria or fungi that weaken the tree and lead to tree death. — **Figure 12.** Cankers occur on the trunk following winter injury. In some cases, surrounding tissues heal. In severe cases, the trunk becomes invaded by bacteria or fungi that weaken the tree and lead to tree death.

Figure 13. A peach fruit infected with peach scab disease. — **Figure 13.** A peach fruit infected with peach scab disease.

Insect Pests

Peach tree borer can be a serious pest because of the potential for tree death, particularly for younger trees. The larvae feed on the internal trunk tissues, eventually killing the tree. To prevent trunk borer infestation, a trunk application of insecticide can be made in July and another in August. Select an insecticide labeled as appropriate for fruit trees and apply it according to its label instructions for effectiveness and safety. Keeping grass and weeds short around the trunk will also lessen the chance for borer egg laying.

Insects that directly damage fruit include the plum curculio, oriental fruit moth, stink bugs and earwigs. Plum curculio insects damage fruit by their egg-laying in the month following bloom, which is usually June. The damage they cause leads to misshapen fruit. Tarnished plant bugs will also cause the fruit to become misshapen. Oriental fruit moths will feed on fruit early in their development and again as they ripen. Earwigs will also feed on ripening fruit. Keeping grass and weeds short around the base of the trees reduces earwig problems. (To view images of common fruit pests, visit the Fruit Pest Photo Gallery.)

Fertilization

Most soils in Maine are sufficiently fertile to take care of the nutrient needs of fruit trees. Trees in sandy soils will benefit from periodic fertilization. Mature trees can be fertilized with one-half pound of 10-10-10 fertilizer once a year in May. On younger trees, reduce the rate by half. Use micronutrient-containing fertilizers conservatively, because peaches are sensitive to high levels of the micronutrient boron. Water-soluble fertilizer mixes with easy-to-follow instructions can also be used to fertilize fruit trees. Application of nitrogen-containing fertilizers should be avoided after June, since nitrogen fertilizer can lead to bland-tasting fruit.

Figure 14. Peaches and other stone fruit trees are commonly trained to be short with four limbs growing outward from the center. — **Figure 14.** Peaches and other stone fruit trees are commonly trained to be short with four limbs growing outward from the center.

Pruning

Peach trees are typically pruned to have a spreading or vase-shaped canopy (Fig. 14) but can be trained in any shape or allowed to grow naturally. The vase-shaped training, also called “open center,” is preferred when a shorter tree is desired. To achieve the open center shape, trees can be pruned back to 2.5 feet above the soil, which may be below any existing side branches (Fig. 15). This will force lateral buds to sprout and grow new shoots. Less severe pruning is an option involving pruning off all but three or four side branches, and this will result in limbs being higher from the ground than with more severe heading of the main branch. An additional option is to prune the tree very little, cutting off dead or broken branches and tips, leaving the remaining ones intact. In the subsequent years, prune the tree as little as possible to encourage the tree canopy to fill out quickly (Fig. 16). Branches growing back into the center of the tree canopy should be removed each year. When the tree has grown to the desired height, usually 8 to 10 feet, the leaders can be pruned back each year.

Figure 16. A 2-year-old peach tree pruned as an open center or vase-shaped tree. — **Figure 16.** A 2-year-old peach tree pruned as an open center or vase-shaped tree.

Peach trees reach full production typically six years after planting. Mature trees should be pruned annually and in a way that allows some sunlight to reach the lower branches. Small branches on peaches frequently die in winter, and these should be pruned off each year.

Figure 17. Two peach flower buds on either side of a leaf bud. — **Figure 17.** Two peach flower buds on either side of a leaf bud.

Flower buds occur along the length of young shoots (Fig. 17). Avoid pruning most of these young shoots after winters in which flower buds are killed by cold. Following mild winters when most or all flowers remain alive, 25–50 percent of these young shoots may be pruned with thinning cuts to allow more sunlight into the tree canopy.

To ensure maximum winter hardiness, delay pruning until early springtime after the coldest temperatures have occurred. To encourage rapid healing of pruning cuts, prune after the tree has begun spring growth (sometime in April), but before bloom.

When to Harvest

Peaches can be harvested when the skin color changes from light green to yellow (Fig. 18). When the peel has changed to orange, the fruit is a fully ripe peach and will quickly degrade or rot. Peaches will continue to ripen somewhat once they are picked. When peaches are harvested green, they are too immature to fully ripen. Most peach varieties will ripen unevenly, so some fruit will be ready to pick while others may still be green. For this reason, spot picking will be necessary.

Figure 18. Peaches at different stages of ripeness from unripe (left) to fully ripe (right).

For More Information

Hoover, Tiepe and Foulk. 2024. Growing stone fruits in the home garden | UMN Extension, University of Minnesota Extension.
Lord, W., and A. Ouellette. 2013. Growing Peaches and Nectarines in the Home Garden (PDF). University of New Hampshire Cooperative Extension.
Roper, T., D. L. Mahr. 1998. Growing Apricots, Cherries, Peaches, & Plums in Wisconsin (PDF). University of Wisconsin-Extension.
2023. Peach Tree Pruning – Managing Light and Crop Load. PennState Extension.

Information on Variety Selection

Daniel Webster. March 2023. Home Orchards: Stone Fruit Variety Selection, Penn State Extension
Warmund, M. 2012. Home Fruit Production: Peach and Nectarine Culture. University of Missouri Extension.

Variety evaluation and cold hardiness research was funded by the Maine Specialty Crop Block Grant Program, made possible by a grant/cooperative agreement from the U.S. Department of Agriculture (USDA) Agricultural Marketing Service, by the Essex County Fruit Growers Association of Massachusetts, and by the University of Maine Agricultural and Forest Experiment Station.

Photos by Renae Moran.

Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.

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