Site Selection
Long summer days, cool nights, and a mostly dry season are ideal conditions for growing fruit trees. Fruit trees require freezing or close to freezing temperatures during the winter, but generally need at least 150 days between the last spring frost and the first fall frost so blossoms are not damaged in spring and so fruit will mature in the fall.
Do not plant in low spots or areas that flood frequently. If you are planting on a site where the soil is shallow because of a hardpan, break through the hardpan when preparing for planting. Do not plant trees too close together, as this may cause poor growth.
Most fruit trees do best in areas with full sun, good air movement, and well-drained soils at least 4 feet deep. Pears do best in soils at least 6 feet deep. Plant in unshaded areas as much as possible to prevent diseases. The best soils are fertile, slightly acidic sandy loam soils free of alkali or salinity. Avoid sandy, high clay, or shallow soils, although pears can tolerate clay or wet soils better than other fruit trees can.
Chilling hours are defined as the number of hours the temperature is below 45° F. It is important to make sure your area has adequate chilling hours because inadequate chilling will result in delayed foliation and uneven fruit development.
Pears are best adapted to areas with adequate chilling hours for most varieties--600 to 800 hours below 45° F to fully satisfy the chilling requirement.
Planting
The ideal planting time for fruit or nut trees is during the dormancy period in the bare-root stage during winter or early spring. Plant as soon as possible after receiving them from the nursery, and do not let them dry out. The roots are very sensitive and must be kept wet and protected from harsh temperatures. Pack roots in peat moss or similar material and keep plants in cool, shady locations until ready to plant.
Avoid planting in a hole or a low-lying area to prevent diseases such as root rot. Plant in raised beds, or on a ridge or mound of soil several inches high and several feet across in areas where drainage is poor or soil is highly amended. Plants will settle as organic matter in the soil decomposes. The hole should be about 1.5 to 2 feet wide and about 1.5 feet deep. Do not dig the planting hole any deeper than the roots of the tree as purchased.
When you are ready to plant, remove the packing from the root system and examine the roots. Cleanly remove broken or decayed roots prior to planting. Soak the roots in cool water for about 6 to 12 hours and then place the tree in the hole, being careful to spread out the roots. When planting, make sure all the roots are in their natural position. Avoid curling them around the planting area. Refill the hole with the original soil from the site and avoid adding organic amendments and fertilizers. While refilling the hole, settle the soil around the roots to avoid air pockets. Leave the graft union 2 inches above the soil line. Water in after planting. Fertilizer is not usually necessary the first year.
Watering
Fruit and nut trees require consistent, uniform soil moisture. Water is very important for young trees, especially during the first year when the root system is developing. Stress during early growth or during fruit production will reduce yields and fruit quality and may make trees more susceptible to boring insects or diseases. Moisture should be replaced well before the trees begin to show stress. Young trees may need up to 3 to 5 gallons of water per week. Avoid frequent light watering with sprinklers as this creates a shallow root system. A garden hose, soaker hose, or drip system can provide good deep watering. Sandy soils may have to be watered every 3 to 5 days; heavier soils may need only to be watered every 1.5 to 2 weeks. During hot weather, young trees may need to be watered more often. Avoid prolonged saturation. If weather is windy, be sure to stake young trees, otherwise they will lean in wet soils.
Do not water established trees near the trunk and lower branches, as this promotes root and crown disease. Water plants when needed around the drip line and beyond. Avoid overhead sprinklers when possible. Try to water deeply and infrequently (every 2 to 3 weeks) by irrigating for 12 to 24 hours to wet to a 3- to 6-foot depth. If using a drip system, water more on a continual basis. Reduce water in late summer and fall.
Pruning
Pruning mature trees consists of balancing vegetative growth with bearing wood. Pear trees normally bear on the terminal end of spurs located on wood 2 years old or older. Fruit spurs are productive for at least 5 years and longer, although the best production is from fruit wood that is 3 to 5 years old. As the trees reach 6 to 8 years of age, you should start to renew the fruiting spurs by pruning out one-third to one-fifth of the older fruit wood. Avoid cutting out large scaffold limbs because they tend to decay. Also avoid cutting into the branch bark ridge, which is where new tissue that promotes wound closure originates.
Proper pruning can help prevent diseases such as powdery mildew, fire blight, and bacterial blast and canker. Do not overprune as this may lead to sunburn, which may make trees susceptible to borers.
Thinning
Pears rarely require thinning except under very heavy crop loads. Even then the thinning is not severe. An exception is the Asian pear, which often requires heavy thinning. Generally, if the scaffold limbs of young bearing trees are splitting under the fruit load, tie them up with a strap or rope early in the season to prevent injury. If the crop set is very heavy, remove small and blemished fruit a few weeks before harvest. If you are required to thin, leave about 6 inches between the fruiting clusters, keeping one or two of the largest fruit per cluster. Thinning should be done to allow a closer spacing near the base of the branch and a wider spacing near the tip. This is done to avoid having the branches bend or break from too much weight.
Training
Young pear trees are pruned to develop tree structure; this is commonly referred to as training. The goal of training is to develop a sturdy tree and canopy that is capable of producing large crops and fills its allotted space. Training occurs during the first 2 or 3 years after planting and should be completed before significant fruit set is allowed.
Pears are best trained to an open center, vase or modified vase system. Because pears are highly susceptible to fire blight, some leaders may be killed by the disease. A multiple leader system will ensure there are replacement scaffolds present to retain fruitfulness if some are killed out by the disease. Proper tree training also can help prevent disorders such as sunburn. Pears are well suited to many other training systems, including modified lorette, cordon, and espalier.
First-Year Pruning
Generally, pears are cut back to 24 to 32 inches above the graft union after planting. However, fruit-bearing wood will be higher up in the tree, making harvesting and pest control operations more difficult. Heading newly planted trees at green tip often gives more and better angled limbs from which the scaffolds are chosen. If wide-angled branches are well placed, cut them back to stubs, leaving one or two buds. Remove obvious crossing limbs and suckers. Whitewash or paint with diluted interior water-based paint to protect from sunburn and reduce borer damage. Avoid water stress, especially in the first 2 years of development.
Fertilizing
Maintaining a good fertilization program can keep your plants vigorous and help prevent infections of bacterial blast or canker, oak root fungus, and powdery mildew.
As a general rule, nitrogen should be applied annually, usually during the growing season. To improve fruit quality and color, nitrogen levels should be low but not deficient as the harvest nears. Nitrogen fertilizer can be applied in the spring or split between spring and just after harvest. Excessive nitrogen can cause softer fruit, poor fruit color, and reduced storage and shelf life; it can also increase problems with numerous pests. Typically, mature trees should receive about 3 to 5 pounds of ammonium sulfate per year or 2 pounds of urea per year depending upon soil fertility and local growing conditions. Apply about a foot away from the trunk, continuing to the drip line, and water thoroughly after application.
Zinc is also commonly deficient. Affected trees have small new leaves. This deficiency is best corrected by spray applications. Spray with a "chelated zinc" during the growing season. Repeat if new growth still shows deficiency symptoms.
Harvesting and Storing
European pear varieties ripen best off the tree. Fruit that is left on the tree doesn't develop full flavor. Pick the fruit when it is green and hard but of mature size for the variety. The stem should break off the spur easily when the fruit is twisted upward. If the spur breaks off the tree, the fruit is not ready to pick. Allow the fruit to ripen in a cool place in a fruit ripening bowl or paper bag. You may store fall-ready varieties for several weeks in cold storage (below 40° F) and bring them out for ripening at room temperature.
Asian varieties should be allowed to ripen on the tree. The fruit will generally turn from green to yellow and the flesh should be sweet and juicy. Asian pears will hold on the tree for quite a while after they have ripened. It is better however, to keep them in cold storage until ready to eat. Asian pears can be stored for several months, depending on variety.
Sanitation
Sanitation is a necessary management tool in all home orchards because of the long life of trees. Perennial weeds, nematodes, and certain disease pathogens are difficult to control after trees become established. Prevent the introduction or spread of infestations by removing infected limbs and fruit. Disinfect cutting tools periodically during pruning and whenever they come into direct contact with diseased tissue. Clean equipment used in other areas to avoid introducing pathogens, nematodes, or weeds.
Sanitation Tips
- Remove diseased wood as soon as it becomes evident. Dispose of the prunings immediately to prevent them from becoming a source of new infections.
- Remove stumps, brush piles, and debris. Brush, thinnings, and other debris can harbor diseases as well as vertebrates and insects. Removing stumps may prevent population buildups of wood-boring insect pests.
- Remove diseased shoots, leaves, and fruit on trees and on the ground.
- Remove roosting, nesting, or resting areas that may attract large numbers of crop-destroying birds.
- Keep the tree crown area free of weeds to reduce crown rot infections.
- Spot-treat perennial weeds to prevent their spread.
