Fertile soil is as important to your fruit trees as sunlight and water. And the most important consideration about soil is how well it drains. Fruit trees need well-drained and deep soil – anywhere from 4’ to 9’, and berries and grapes need a minimum of 3’. If your site is shallow or poorly draining, you’ll spend more effort fighting pests and managing watering, and your plant still likely won’t thrive.
There are three basic types of soil – clay, sandy and loam.
- Clay soils hold together tightly, and that’s a sign your tree’s roots may have difficulty penetrating it. If when you dig in your soil, it clings to your shovel or becomes rock hard, you have clay soil.
- Sandy soil is the opposite of clay. It barely holds together at all. This makes it easy to dig in, but sandy soils are not very fertile.
- Loam is a term for soil that is the happy medium. It has enough clay to be fertile and enough sandy quality to drain well.
The Dig Test
To check the drainage quality of your soil, simply dig a hole a foot or two deep and fill it with water. Then watch the clock. How fast does the water drain?
- Gone in an hour or two? Excellent!
- Drains overnight? You have adequate drainage.
- Longer standing water? That’s poor drainage.
If you have poor drainage, look for another location to plant. Or you can till the soil deeply in a wide area, and work in some well-decomposed compost. Or you can plant in a raised bed filled with good quality soil.
The pH scale measures whether the soil is acidic, neutral or alkaline. Soil with a pH below seven is considered acid. Above seven, the soil is alkaline. Fruit trees tend to grow best in soil that is near the “seven” mark (neutral) or slightly below (slightly acid). Blueberries and lingonberries like acidic soil, around 4.5 to 5.5 on the pH scale. The internet is filled with information about testing the pH of your soil, but the easiest method may be to check with your local garden center.