Although most vegetables and herbs need neutral or even chalky soil in order to thrive, the majority of fruit trees prefer soils on the acidic side. But it's important to determine exactly how acidic your soil is, because a few fruit trees demand neutral or even alkaline soils to thrive. In that case, the acidic soil needs to be amended.
While many fruit trees tolerate or prefer slightly acidic soils, few thrive in soils with an extremely low pH level. Neutral soils have a pH level of 7.0, while slightly acidic soils range from 5.5 to 6.9. If your pH level is significantly lower than this slightly acidic range, use a garden amendment like limestone to make it less acidic. For every pH unit of 1 that you wish to raise the soil, use 2.27 to 4.54 Kilogram of limestone per 100 square feet. To raise your pH level from 4.5 to 5.5, for example, use 4.54 Kilogram of limestone on a 10-foot-by-10-foot planting area, or 2.27 Kilogram on a 5-foot-by-5-foot planting area.
Apple trees favour slightly acidic soils. For home orchards, dwarf trees are available, as well as miniature trees that fit into containers. Apples grow best in USDA hardiness zones 4 to 9. According to Binghamton University, apple trees are more challenging to grow than other fruit trees, and may require chemical spraying to thwart common pests and diseases. Among their benefits are long-keeping fruit and highly ornamental spring blooms. Grow them in full sun for optimum yield.
Like apples, apricots are suitable for sunny gardens with slightly acidic soils located in zones 4 to 9. The trees aren't as bothered by pests as apples, but do have a delicate constitution when it comes to frosts after they come out of dormancy. Gardeners who live in areas with occasional late-spring frosts may find their fruit crops ruined for a full growing season when a harsh frost strikes, if the crops aren't properly protected. Home apricot growers have options ranging from miniature trees for the patio to full-size shade trees.
Plums grow in zones 4 to 10, favouring slightly acidic soils in full sun. They're prized as landscaping trees for their abundant spring blossoms and their fruit. Plums are less bothered by pests and weather fluctuations than apples and apricots. Plums are available in dwarf form, but they're rather small as full-size trees, rarely exceeding 15 feet in height.
Some fruit trees thrive in a number of soil types, ranging from acidic to neutral to alkaline, as well as from clay to sandy, notes Lee Reich in "Uncommon Fruits for Every Garden." Trees that may tolerate acid to slightly acid soils are serviceberries, beach plums, paw paws, raisin trees, persimmons, gumi and jujubes. Ask a reputable nursery if these trees thrive in your garden's growing conditions.
Other Fruiting Plants
Some non-tree fruits are known for their preference for acidic soil. Among them are lingonberries, cranberries and blueberries. For gardeners with large stretches of highly acidic land, these fruits may make better choices than trees that prefer only slightly acidic soils.