Fruit Trees and Soil
Fruit Trees and Soils – A Love Affair
“The soil is the great connector of lives, the source and destination of all.” – Wendell Berry
Of all things necessary to grow fruit trees – or anything else, for that matter – soil is perhaps one of the most overlooked and underappreciated. Soil is where it all begins and where a tree (or other plant or animal or…) ultimately ends up.
To grow anything successfully, the soil plays a pivotal role. Here are some ways for you to know if your soil is right for fruit trees or other garden plants.
1) pH – Without going into a bunch of boring chemistry, soil pH is the measure of how acidic or basic a soil is, using a scale from 1-14. The number 7 on this scale is considered neutral and anything below this number is considered acidic. Anything above 7 is considered basic, or alkaline. Fruit trees normally do well in soils with a pH range around 6-6.5, though a lower or higher pH isn’t generally major problem. Almond trees prefer a soil pH in the 7-7.5 range. Blueberry plants grow best with a soil pH around 5. Other plants, like azalea, do well with a pH from 4.5 to 6. Plants that are picky about pH, like almonds, blueberries, and azaleas, don’t grow well outside of their pH range. And this probably goes without saying, but here it is anyway: very few plants of any kind grow on the extreme ends of the pH scale. How do you know what your soil pH is? Try a soil test from a university or private lab. Some home test kits for pH are also available.
2) Soil texture – Soil texture refers to size of soil particles. Sandy soil has larger particles (still tiny to the naked eye), but when wet sandy soil is held and squeezed by the hand and released, it falls apart quickly. Silt soil has slightly smaller particles and when it is wet and squeezed, it falls apart after few minutes. Clay soil is made of small particles and when it is moist and squeezed, it will hold its shape almost indefinitely. Most soils are a blend of the three major soil types, with many soils being classified as sandy loam or clay loam – loam is a soil with a mixture of the two or more of three soil types. Here in East Texas and in many other parts of the South, clay soil is prominent in many places. In bottomlands and areas along rivers, the soils tend to be loam or sandy. As a general rule, sandy soils drain water quickly, loam soils drain water more slowly, and clay soils hold water for extended periods. Fruit trees grown on sandy hill tops may need more water; fruit trees in clay soil will need less. Well-drained loam soil is generally ideal soils for garden crops and fruit trees, though with proper care garden plants and trees of all kinds can be grown in virtually every soil texture. Soil texture also impacts how easy it is for plant roots to pass through. The roots of plants grown in sandy soil will easily spread; plants grown in clay soil will have a more limited root system. Of all the soil types, it is most challenging to grow fruit trees in clay soil.
3) Nutrients – Nutrients in soil are the result of natural decomposition or fertilizer added by the gardener. Most soils have a least some naturally-occurring nutrients. The three major nutrients that most gardeners know are nitrogen, phosphorus, and potassium, usually known by their chemical symbols N-P-K. All products labeled as fertilizer sold in the United States list the nutrient content as a percentage of total weight (confused yet?) using three numbers. For example, 10-10-10 fertilizer is 10% nitrogen, 10% phosphorus, and 10% potassium. Most fertilizers recommended for fruit trees are balanced fertilizers like 10-10-10. Organic fertilizers tend to have lower nutrient content that is released over a longer period of time. They also usually have micronutrients, like calcium and magnesium, which benefit plants. Fruit trees do well with either conventional or organic fertilizer, but they do need fertilizer. The nutrient content in native soils just won’t provide adequate nutrition for a fruit tree to consistently bear fruit. The best way to know what your soil’s nutrient needs are is to take a soil test.
4) Microorganisms – Microorganisms in soil are (obviously!) invisible to the naked eye. And, like most other things in this world, there are is a good and bad side to them.
The Bad: soil parasitic nematodes are a problem for fruit trees in various locations throughout the world. There is really no way to know you have parasitic nematodes until you see the damage to the tree. Parasitic nematodes feed off the root system of the trees, causing stunted growth and reducing the nutrient uptake of the tree. Over time the weakened tree may die of disease. Soil can be fumigated for nematodes, though this is an expensive fix that may not last. Some gardeners have had limited success with soil solarization. Soil solarization involves tilling the soil and placing clean plastic sheeting over it in summer. This process can be repeated several times. Nematodes that feed on parasitic nematodes are available from some garden supply companies. Other bad microorganisms include over-wintering fungi and bacteria
The Good: But don’t fear! Most microorganisms in soil are not harmful and many are beneficial. Healthy soil helps plants more efficiently use soil nutrients. A population of beneficial microorganisms helps protect plants from diseases that enter plants through the roots. Beneficial nematodes keep parasitic nematodes at bay in healthy soil. Nitrogen fixing plants, such as beans and peas, use certain soil bacteria to bring nitrogen from the air to the soil. Manure tea, compost tea, compost, and other organic matter placed around a tree or in the soil helps the soil maintain good health as the fruit tree or other garden plant grows.
Want to tell us about your ideas to improve soil health? Leave a comment in below – we’d love to hear it!