Getting The Soil Just Right For Organic Stone Fruit Production

Vernon Peterson, an organic grower at Abundant Harvest, quickly discovered after transitioning to organic agriculture that soil health was essential for growing healthy stone fruit. In an interview with Growing Produce, he explained:

“In order to farm organic fruit, soil is your No. 1 concern,” he says. “If you get your soil right, the trees will resist quite a few diseases.”

So, how do you create the best soil for fruits and vegetables to thrive with fewer chemical inputs? Here, we’ll look at ways to build healthy soil to ensure a successful stone fruit season each year.

Soil Requirements for Stone Fruit

Whether you’re an organic or conventional grower, the soil requirements for stone fruit trees are the same:

• Deep, well-drained, humus-rich soil
• A pH between 6 and 7

Let’s take a look at each of these two key requirements and how to optimize the soil in your orchard.

Deep, Well-Drained, Humus-Rich Soil

Just like the best soil for fruits and vegetables, the best soil for stone fruit needs plenty of depth so that the trees can put down strong roots and grow to their maximum height. The trees also need adequate drainage to prevent problems like root rot and fungal infections.

Fortunately, using techniques that build up your topsoil creates the ideal conditions for a successful stone fruit season. However, if you’re short on time, you can improve heavy soils for planting stone fruit quickly with the addition of gypsum and plenty of organic matter. Mounding the soil before planting can also help to ensure adequate drainage.

pH between 6 and 7

The acidity or alkalinity of the soil affects the health of anything you plant, including stone fruit. Generally, the best soil for fruits and vegetables has a pH between 6 and 7, and 6.5 is often cited as the ideal pH for growing food crops.

Soil that is either too acidic or too alkaline could be a result of mineral content, climate, or the texture of the soil — and indicates that your soil is not as healthy as it could be. While your stone fruit trees may still do well in soil with a pH between 5.5 and 7.5, it’s preferable to improve your soil to ensure the ideal conditions in your orchard.

As soil pH is an indicator of soil health, techniques that create the best soil conditions for fruits and vegetables should naturally improve the pH as well. Depending on the current state of your soil, consider the following soil-improvement techniques:

• Add lime to the soil
• Apply nitrogen fertilizer to the soil as needed
• Increase organic matter with cover crops and crop rotation
• Add compost and other organic matter to the soil

Testing the Soil

The best soil for fruits and vegetables will naturally lead to a healthier stone fruit season. However, it’s not always possible to be sure that your soil is stone-fruit ready by simply feeling and smelling the soil. Commercial growers — and especially those who manage large areas of land — invest in regular (sometimes annual) soil testing to make sure their practices are actually obtaining the desired results. Ideally, regenerative soil practices together with annual testing will lead to a reduced need for fertilizers and other costly amendments to the soil.

Before 2014, most soil tests determining the best soil for fruits and vegetables provided information about the soil pH, nutrient levels, and the amount of organic matter present in the soil. Today, more comprehensive soil tests are also available. For example, the Solvita Soil Test and Cornell Test go beyond the basic parameters to measure overall soil health from several different angles, including the availability of nutrients to soil microbes and the ability of the soil to resist disease.

Organic-Friendly Soil Fumigation

While the best soil for fruits and vegetables will go a long way towards preventing some of the most common stone fruit season diseases, soil fumigation is often necessary before planting to prevent soil-borne diseases from taking hold.

For organic farming, growers can use approved biofumigants like Dominus® — the first biopesticide approved for both conventional and organic use. Copper is another common product that is used preventatively in organic orchards, but its effectiveness against bacterial diseases in stone fruit is inconsistent.

Varieties Matter

Depending on the climate and microclimate where you grow your crops, even the best soil for fruits and vegetables won’t necessarily produce healthy crops if they’re planted outside of their ideal environment. Once your soil is healthy and ready for stone fruit, invest some time and effort in finding out which varieties grow best in your area and how each variety is best positioned. For example, some combinations of stone fruit varieties help to boost pollination when placed upwind, but other varieties too close together can present a recipe for bacterial disease.

Local growers, nursery staff, and agricultural research (e.g. publications from UC Davis) can help you select the correct stone fruit tree varieties for your orchard and prevent problems before they begin.

How Long Your Orchard Will Last

According to Peterson, an organic stone fruit orchard should usually last for around 20 years. Even when you begin with the best soil for fruits and vegetables, your land still needs to rest and replenish before another cycle begins. To ensure a successful stone fruit season, organic growers can select several stone fruit varieties that ripen for harvest in quick succession. This means you have something to sell from the very beginning to the end of the season.

To maintain the best soil for fruits and vegetables over time, Peterson suggests replanting 5% of your total acreage each year, planting sudangrass, and letting the land lie fallow for a full 12 months before starting again with a different variety. This results in 85% productivity on your land and ultimately, healthier soil and stone fruit.

Partner with Fruit Growers Supply

Serving growers since 1907, Fruit Growers Supply Company is your one-stop-shop for fruit supplies around the U.S. Offering crop-specific irrigation systems, water testing, and products that are approved for organic orchards, we have everything you need to build the best soil for fruits and vegetables. To learn more about the services we offer, we invite you to explore our website and contact our team to schedule an on-site assessment.