Although apple trees can grow in many soil types, the quality of the soil can affect the health of the tree and the density of your apple harvest. By checking your existing soil and making some basic changes, if necessary, you can offer your tree optimal growing conditions for fruit production.
Apple trees can grow in soils that are less than ideal. However, they do best in soils ranging from a sandy loam to a sandy clay loam that drains very well. Drainage is important to the health of your apple tree's root system. If you are planting a new tree, have the soil tested by your county agricultural extension to see what amendments it may need. With some amendments, you can grow apples in areas where the soils aren't necessarily ideal.
If your soil is overly sandy, add clay and compost for organic matter. The exact amount you should add will depend on the quality of soil you are starting with, but start by adding 10 to 15 percent clay and about 20 percent compost. The clay will help retain water and the compost will add nutrients. The natural sand in the soil should help it drain fast enough for your tree.
Heavy clay soils retain too much water and can cause root problems with your apple tree. If your soil is primarily clay, add sand and compost to help create a soil better suited for growing apples. The exact amount of sand and compost will depend on the existing composition of your soil, so check with your county agricultural extension for precise advice. However, for very hard clay soils, add around 30 to 40 percent sand and about 20 percent compost for organic nutrients.
Many loamy soils may not need much augmentation. Whether it's necessary will depend on the density of the soil and how fast it drains. If your loamy soil drains slowly, you may need to add 10 to 20 percent sand. In most cases, with loamy soil, you wouldn't add clay. Loamy soils tend to hold enough water for most apple trees.
Soil acidity is very important for apple production. Most apple trees do best in soils with a pH of around 6.5. Taking your soil in to your county agricultural extension for analysis can result in good advice on soil composition and acidity for your planting location. If your soil is too alkaline, or higher than 6.5 pH, add things like peat moss, sulfur, or a number of other commercial products to create a more acidic soil. If your soil is highly acidic, you may need to add powdered limestone.