By Mary Small, Colorado State University Cooperative Extension, Urban Integrated Pest Management
The appearance of purple spruce needles usually points to root dehydration. If the damage appears during the winter or early spring, it's probably the result of winter injury.
All spruce trees, but especially those growing in or near lawns, need water during the dry fall and winter months. This keeps the needles hydrated and healthy. Other factors can dehydrate spruce roots and should be considered when diagnosing the problem. For example, de-icing salts and excess fertilizer can also cause or contribute to the off-color because they dehydrate roots. A girdled root cuts off or reduces the amount of water reaching the needles, causing purple needles. Any activity that damages spruce roots (like trenching or digging) also prevents them from absorbing water well, producing the off-color.
Photo: Judy Sedbrook
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010