Soil for Spruce Trees

Soil

• Spruce trees grow best in a well-drained, moist, fertile soil. The tree prefers an acidic soil with a pH ranging between 5.0 and 6.0. The growth rate of the tree slows when planted in poorly drained clay soil or in alkaline soil that has a pH of over 8.0. Apply liquid-based fertilizer to the soil for best absorption, using a 4-4-4 formulation, recommends the Montana State University Extension.

Planting

• Plant spruce trees during fall after the first hard frost or in early spring as soon as ground can be worked. Dormant trees have a better success rate than transplanting actively growing trees. Avoid transplanting during hot and dry weather as this makes new trees prone to drought stress. Mulch newly planted trees to reduce chances of frost heaving in the roots. Remove any plastic burlap or wires around the root-ball prior to planting, as these will not decompose.

Water

• The required amount of water for the tree depends on the soil, air temperature and wind speed. Applying mulch under trees helps to conserve moisture in roots. Transplants need more frequent watering than the more established trees. Water trees deeply, preferably with a drip irrigation system. Watering at a shallow rate produces shallow roots that in turn create weak growth. Stop irrigating the trees by the middle of August. This will harden off the trees for the coming winter and reduce potential cold injury.

Pruning

• Spruce trees have a naturally symmetrical form and when planted in open spaces, the trees do not require too much pruning. Prune trees only lightly as this helps to develop a dense crown. When pruning, take care not to remove over a third of the entire foliage area and never touch the top of the tree. Recommended time to prune the trees in order to obtain a desired shape is during early June. Cut and remove damaged tree areas at any time of the year.