Good cherry tree companion planting starts with knowing what to avoid. Black walnut trees pose the biggest threat to your cherry trees. Keep these two species far apart if you want healthy cherries that produce good fruit each year. The wrong neighbors can ruin years of careful growing in your yard.
I learned this lesson when I planted a young cherry tree too close to my neighbor's walnut. The cherry struggled for two years before I figured out the problem. Its leaves stayed yellow and small no matter what I did. The branches grew weak and thin. I tried extra fertilizer and better watering but nothing helped. Once I moved that tree to the other side of my yard, it took off and now gives me buckets of fruit every summer.
Black walnut trees release a chemical called juglone into the soil around them. This compound stops other plants from growing near the walnut. Cherry trees suffer badly from juglone exposure in their root zone. Their roots absorb the toxin and the whole tree starts to fail. The effects spread beyond the walnut's canopy drip line. Juglone can travel 50-80 feet (15-24 meters) through the soil from a mature walnut tree. You need to measure this distance before you plant.
Among the plants to avoid near cherry trees, the nightshade family also causes problems for your fruit. Tomatoes, peppers, potatoes, and eggplants carry diseases that spread to stone fruits. Verticillium wilt moves from these vegetables into cherry tree roots through the soil. This fungal disease lives in the ground for years. You need to keep at least 10 feet (3 meters) between your cherry and any nightshade crops to stay safe.
Heavy grass around the base of your cherry tree competes hard for water and nutrients. Turf grass sends roots into the same top soil layer where young cherry roots grow. This competition stunts young trees and cuts your fruit production in older ones. Keep a bare mulch ring 3-4 feet (1-1.2 meters) wide around each cherry trunk. Your tree will grow faster and produce more fruit without grass taking its resources. Wood chips work great for this mulch layer.
Other stone fruits like peaches, plums, and apricots count as bad neighbors for cherry trees because they share diseases. Bacterial canker, brown rot, and powdery mildew jump between these related species. If one tree gets sick, the disease spreads to all the others nearby. I once lost three trees in one season to brown rot that started on a neglected plum tree in my orchard. Plant your different stone fruit types at least 20 feet (6 meters) apart to limit disease spread.
Proper cherry tree spacing matters for more than just disease control. Your cherry needs room for air to flow through its branches. Crowded trees stay damp and grow fungus faster than you can treat it. Standard cherry trees need 20-30 feet (6-9 meters) from other trees in your yard. Dwarf cherries can grow 8-10 feet (2.4-3 meters) apart since they stay smaller throughout their lives. Give your trees the space they need to thrive and stay healthy.
Good companions for cherry trees include clover, comfrey, and chives. Clover fixes nitrogen in the soil and feeds your tree for free all season long. Comfrey mines nutrients from deep in the ground and brings them up to your cherry's roots. Chives repel aphids and other pests that bother cherry trees. These helpful plants make your cherry healthier while the bad neighbors make it sick. Choose your cherry tree's neighbors with care and you will enjoy better harvests for years to come.
Read the full article: 15 Cherry Tree Varieties for Your Garden
