Apple and Yarrow

Yarrow (Achillea millefolium) planted near apple trees draws in predatory insects and parasitoid wasps that prey on codling moth larvae and eggs, reducing pest pressure without chemical intervention. The pairing works best when yarrow is established along orchard rows or at the drip line rather than directly competing with tree roots in the immediate root zone.

Yarrow tolerates a wide range of soils and is drought-tolerant once established, which generally aligns with apple's preference for well-drained ground. Timing matters: yarrow should be in flower during peak codling moth flight periods, typically late spring through summer, to maximize beneficial insect recruitment. This pairing is less useful in heavily mowed orchards where yarrow is cut before it blooms, eliminating the nectar source that attracts the beneficial insects. It also offers limited benefit in zones or seasons where codling moth pressure is already low. One to three yarrow clumps per tree is a common planting density, though no published trial data establishes a firm optimal ratio.