Gardeners are disappointed when a portion or all of a small or tree fruit planting dies. Injury to the trunk, crown (area at the soil line) or roots generally is the primary cause of death. Winter cold, poorly-drained soil, mouse and rabbit feeding damage, root and crown diseases and borers- alone or in combination-can all cause loss of plants. Death of plants can result from two or more of these factors interacting to weaken or injure a plant; therefore, it may survive.
Poor Soil Internal Moisture Damage
Poor internal soil drainage is the major cause of death of fruit plants. These conditions occur in soils high in clay content, in soil with an impervious subsoil or on sites where a high water table exists for an extended period of time.
Roots of cherries, peaches and nectarines are most susceptible to injury from soggy, wet soils. Pears, apples and plums are somewhat more tolerant but also can be injured by extended periods of wet soil conditions.
Root or crown damage from excess moisture is readily apparent in browning of inner bark tissue on these parts. Damage often is not apparent for several months after it occurs and may be associated with various root and crown diseases that readily invade the injured tissue.
Choosing well-drained sites for planting fruit crops is an essential step to reducing plant losses. To test for soil water drainage, dig a hole 14 inches deep, pour in five gallons of water, and return to the site one hour later. If water remains, the site is poorly drained. If there are reservations, pour in a second five gallons of water and return one hour later. If the site is poorly drained, the use of raised beds may improve poor internal soil drainage.
Raised beds can be beneficial for berries and fruit trees. For fruit trees, beds should be eight to 10 inches high and six to eight feet wide. For strawberries, raspberries, blackberries and blueberries, beds should be eight inches high and four feet wide. Raised beds will dry out faster and will be more susceptible to cold winds. Incorporate organic matter before planting for greater moisture holding capacity and apply one to two inches of mulch to the surface of the bed. Do not allow water to stand on the edge of the bed. Allow surface water to drain to the edge of the planting.
Winter injury to fruit plants occurs in the lower trunk, crown or roots near the soil surface. If damage destroys all inner bark tissue, the plant will die shortly after growth begins in spring. Damaged inner bark will turn brown, while healthy bark will appear greenish yellow. Severe damage often results in bark splitting or loosening, but this is not always the case. Spring frosts or freezes may cause loss of fruit or leaves, but plants themselves will generally survive if given proper care following the cold period.
Even moderate cold injury to bark, however, makes plants especially susceptible to infestation by borers and diseases such as perennial canker on stone fruits and root and crown rot diseases on apples.
The meadow and pine mouse (vole) feed on apples trees of all ages and may damage other fruit plants. Meadow mice eat the bark of the trunk and roots both above and below the ground level. Pine mice nest underground, eating bark from the roots near the surface. Mouse damage is easily noted by carefully removing soil from around the base of the tree and over the larger roots near the soil surface. Bark completely removed around the trunk or roots by gnawing of the rodents will girdle the tree and cause death or severe plant weakening. Keeping the soil bare and free of grass cover or else mulch around fruit trees or vines will help discourage mice from meeting nearby and feeding on fruit plants. Pea gravel (small stones) placed 1 inch below the soil surface and around the tree will discourage mice. When planting trees, allow the soil to settle one inch and apply the stone two inches deep.
Rabbits feed on bark of trunks and exposed roots of young fruit trees. Rabbit guards, preferably wire screen, wrapped around newly-set fruit plants are suggested to prevent feeding damage. Where plants are extremely girdled by rodents, death of plants usually occurs shortly after growth begins in spring. As with other types of mechanical injury, weakened plants are more susceptible to drought, cold injury or insect and disease infestations. Rabbits will generally feed on apple trees and brambles when the soil is covered with snow for 10 to 14 days. With vinyl guards, put guards on newly planted trees in October and keep the guard on all year.
Plants weakened by a nutrient deficiency become more susceptible to cold injury, borer attacks and fungal or bacterial diseases. Nutritional deficiencies should be prevented rather than attempting to correct them after they occur. Proper attention to accepted pre-plant fertilization practices, the wise use of soil test, and plant analysis recommendations are essential to maintaining fruit plant health and vigor. Fertilizer recommendations are listed in Bulletin 591, and soil and plant analysis services are available to fruit growers through Ohio State University Extension offices throughout Ohio.
Fruit Plant Diseases
Diseases affecting leaves, fruit and twigs of fruit plants usually do not cause plants to die if controlled before the diseases become severe. Uncontrolled, diseases such as cherry leaf spot, fireblight on apples and pears or black knot on plums will eventually weaken trees. This may result in death in combination with other environmental stress factors such as cold injury or drought. Suggestions for control of fruit plant diseases are updated annually and available through county Ohio State University Extension offices statewide in Bulletin 780.
Stone fruits (peaches, plums, cherries and nectarines) are susceptible to peach tree borer and lesser peach tree borer infestations. The peach tree borer feeds on inner bark of the trunk above and just below the soil line. The lesser peach tree borer attacks larger branches and the trunk. Serious infestations of either of these pests can cause individual branches to die or eventually cause the death of the tree. Trees severely damaged by borers are readily injured by low winter temperatures or canker infection. Borer damaged trees may survive for several seasons unless they are stressed by drought, disease infection or cold injury. Control recommendations are available through Ohio State University Extension offices in each county in Bulletin 780.
Drought alone will usually not kill healthy, established fruit plants. Newly-set plants with limited root systems, plants damaged by cold injury or insects and diseases frequently die as a result of lack of moisture. Supply adequate water through the stress period. During June, July and August, apply .6 gallons of water per square foot of root zone every five to seven days if no rainfall occurs.
Proper attention to approved planting techniques, adequate nutrition, disease and insect control and good water management is essential to reducing fruit plant losses. The maintenance of healthy, vigorous plants is a key step in reducing losses to other stress factors such as cold injury or root disease. Avoid disappointment and costly replanting of fruit plants by following good cultural practices. For information on insects, diseases and cultural practices for fruit crops, obtain a copy from your local Ohio State University Extension Office of Bulletin 780, Controlling Diseases and Insects in Home Fruit Plantings, and Bulletin 591, Growing and Using Fruit at Home. For descriptions of insects and diseases, there are many HYG Fact Sheets devoted to fruit crops. Of particular interest, refer to HYG Fact Sheets 1421, 1422, 1423, 1424, 1402, 1404, 1406, 3002, 3006, 2032, 2033, and 3019.