Soils

See also "AppleRootstock Tables"

Roots of most fruit trees grow relatively shallowly but are intolerant of "wet feet". Most are moderate/low water users. Ideally they should have about three feet of soil that is well- drained, however they will grow in shallower soil but, depending on the rootstock, won't endure drought as well. (Because the high water table will not allow roots to grow deep)

Soil Texture: Pome (apple and pear) and stone fruit (peach, plum, apricot, almond, cherry) trees grow best in a loam soil but can be grown in sandy and clayey soil as long as drainage is good. This holds true for most fruits with a few exceptions notably persimmon which does well in sandy or clayey soil and chestnuts which prefer light sandy soil. (Note: "Pears of New York" states that White Doyenne pear trees and a few others are much less susceptible to disease when planted in clay soil)

pH: Alkaline soil (over 7.5 pH) makes iron less available causing the leaves to yellow. Pome and stone fruits do fine in most acidic soils (down to a pH of about 5.0 or a little less) but acid soils make some minerals less available (calcium, phosphorus, and magnesium) and others overly available (such as aluminum and manganese) So if your soil is over 7.5 add an acidifier such as sulfur or an acidic mulch. If it is very acid, add lime. See your extension agent for amounts.

Fertility: There is a wide range of fertility requirements among fruit and nuts such as: grapes and chestnuts like moderately poor soil, pome and stone fruits like moderate soils, black walnuts prefer rich soil.

Depth of roots: Taking apple as an example, the bulk of apple roots are found growing in the top 18" of soil. They do grow deeper in light soil than than they do in heavy soil. Seedling rootstocks (rootstocks grown from seed) retain their taproots which normally grow deeper than feeder roots. (However, the main functions of taproots in apple and most fruit trees are support and sugar storage not the gathering of water. I also suspect that taproots may allow a tree to live longer and endure wetter soil.) Antonovka has one of the most pronounced taproots of all apple rootstocks. By contrast, MM 111 apple rootstock has no central taproot but extensive feeder roots capable of growing in shallow soil better than others due to its tolerance of dry soil. It is for this reason that it does better than many rootstocks on soil with a high water table as well as doing well in very dry soil. Bud 9 apple rootstock has similar tolerances but is not as drought tolerant as 111, however more drought tolerant than most dwarfs. The following have deep roots: Pecan, black and English walnut, oaks, grapes. The following have shallow roots: pea shrubs, pome and stone fruits, kiwis, filbert/hazelnuts, bush cherries, roses, blueberries, lingonberries.

Dry Soils: In general apples and pears are moderately low water users whereas plums grafted to Prunus americana and pears grafted to Pyrus ussuriensis are low water users. There are varying degrees of drought tolerance among apple rootstocks. (See descriptions of individual rootstocks). The following are rated according to those most adapted to those least adapted to dry soils: Prunus americana, chestnuts, MM 111, Bud 118, Malus ranetka and Pyrus ussuriensis, Bitternut (rootstock for pecans), Bud 9, filberts/hazelnuts, (don't like dry soil) and Malus antonovka.

Wet soils: Most fruit tree roots do poorly in wet soil, however, Pyrus communis pear rootstock, persimmon, and juneberry do better than most in wet conditions. Some rootstocks do better than others in wet soils due either to their resistance to crown and collar rots or their greater tolerance of oxygen deprivation. If you plant in wetter soils drainage tile can be used or you can plant in a mound or berm of soil which will make a less hospitable environment for crown and collar rots. The following are rated according to those most adapted to those least adapted to wet soils: Juneberry, Persimmon, black walnuts, pecans (if oxygenated), Pyrus communis, Malus borowinka, antonovka, and ranetka, (last three are apple rootstocks, borowinka being significantly more adapted than ranetka; borowinka and antonovka nearly the same tolerance).

To test soil drainage, pour a gallon of water in a hole in the ground, if it is gone within 24 hours it should be OK for most trees. If it drains between two and four hours you probably have loam soil, more than that is probably clay and less is probably sand, (I say probably because a physical condition such as a shallow hardpan might change the rate of drainage independent of soil texture). It is best to do this test in late spring after the ground has thawed completely and the trees are actively growing. (Usually the wettest time of the year).