7 Best Soil Boosters to Help Fruit Trees Thrive and Keep Pests Away

Healthy fruit trees exhibit strong growth and vibrant green leaves and consistently produce high-quality, delicious fruit. In contrast, struggling fruit trees often show signs such as wilting leaves, drooping branches, and a significant decline in fruit production. They are also more vulnerable to pests and diseases.

One effective way to keep your fruit trees healthy is to support their soil. Healthy soil provides essential nutrients and promotes the activity of beneficial microbes, resulting in stronger trees, reduced pest and disease issues, and increased fruit production. Below, fruit tree experts share their go-to soil boosters for fruit trees, ensuring bountiful harvests for years to come.

Grow Comfrey

Comfrey (Symphytum officinale) is an excellent companion plant for fruit trees, acting as a living mulch, says Holly Simpson Baldwin, co-owner of The Farm Between. Its large leaves suppress weeds and help retain moisture in the soil during dry spells. With a deep taproot, comfrey draws nutrients like potassium and calcium from the subsoil, which are often inaccessible to shallow-rooted fruit trees. Godinez notes the "chop and drop" method allows growers to cut leaves from their comfrey plant and use them as mulch, enriching the soil with nutrients as they decompose. "In the Northeast, comfrey blooms from May to September, providing early nectar for pollinators, which enhances fruit production in gardens and orchards."

Apply Liquid Seaweed and Fish Emulsion

Seaweed and fish offer numerous benefits when added to soil. Seaweed provides a variety of micronutrients and natural growth hormones, while fish emulsion delivers a quick boost of nitrogen that promotes healthy growth. David Fried, the owner of Elmore Roots Nursery, applies a blend of seaweed and fish emulsion from Neptune’s Harvest to fruit trees. He does this by drizzling the solution around the base of the fruit tree on a rainy day. Fried recommends applying this mixture every 10 days during spring and early summer to ensure that fruit trees receive the essential nutrients they need for optimal growth. However, Fried cautions against using this solution in late summer, as it can result in tender growth that may not survive the winter months.

Apply Compost

Compost, often referred to as "liquid gold," is a true game-changer for the health of your fruit trees. It’s packed with essential macronutrients and micronutrients such as nitrogen, phosphorous, potassium, iron, copper, and zinc, all of which play a vital role in enriching soil health. By enhancing soil structure and boosting water retention, compost not only improves the quality and yield of your fruit but also strengthens its immunity against pests and diseases.

To make the most of compost, Fried suggests applying it just inside and outside the drip line—the area that stretches to the furthest tips of the tree's branches. Aim for a 2- to 3-inch layer of nutrient-rich compost. Help it settle in by soaking it with water.

Spread Limestone

Limestone is mainly composed of calcium carbonate and serves several purposes in soil management. It helps to adjust the soil's pH, provides essential nutrients like calcium and magnesium, and enhances overall soil structure. According to Fried, "Limestone sweetens the soil, as fruit trees prefer a pH range of 6.5 to 7.5, while many orchards tend to have a lower, more acidic pH." To apply limestone effectively, spread it just outside the drip line and in the areas between the trees.

Utilize Ramial Woodchips

Ramial wood chips are crafted from the fresh, young branches of deciduous trees and are packed with nutrients and beneficial microorganisms. According to Fried, applying these wood chips is fantastic for orchard health and fosters healthy root growth. They act as a natural barrier against weeds and decompose fairly quickly, functioning as a slow-release fertilizer.

To make ramial wood chips, cut young branches from hardwood trees and feed them through a wood chipper. If a wood chipper isn’t available, you can use garden shears to finely chop young branches that are under 7 centimeters in diameter, then leave them on the soil to break down naturally.

Plant Cover Crops

Cover crops add organic matter to soil, improve soil structure, reduce erosion, manage pests, and retain moisture. Mary Godinez of Cross Keys Farm in Harrisonburg, Virginia, grows various cover crops to help her fruit trees thrive. These non-cash crops are planted during fallow periods (a time when the ground is resting and crops are not in production) to improve soil health.

Godinez suggests planting cool-season crops, such as phacelia, crimson clover, forage radishes, mustards, and grains, in the spring. Once they flourish, mow and till them into the soil before planting warm-season crops, such as buckwheat, sunflowers, and soybeans. In late August, mow the warm-season crops and replant cool-season ones. Mow and till these areas again in October to allow room for winter crops such as wheat or rye.

Top Dress With Seafood Compost

Seafood compost is a rich source of nitrogen and various trace minerals, making it an excellent natural fertilizer that enhances soil fertility and nutrient availability. Kristi Baldini of Windswept Gardens in Bangor, Maine, recommends top-dressing the soil with seafood compost as a mulch each spring. This practice keeps the soil biology active, suppresses weeds, and provides a slow, steady feed to the roots as it breaks down.”

Standard compost is typically made from brown, decomposed materials, such as fallen leaves and wood chips, along with green materials, like kitchen scraps and cut grass. In contrast, seafood compost includes ingredients such as seaweed, shellfish (including lobster and crab shells), and fish waste. Although both types of compost are excellent for improving soil quality, seafood compost generally has higher levels of trace minerals, including calcium, phosphorus, and nitrogen, which come from the bones and tissues of marine animals, serving as an excellent soil booster for fruit trees.