The cone-bearing spruce trees (Picea spp.) attain upright, conical habits with finely textured, stiff needles. Planting spruces in a line to form a hedge or border requires matching the best spruce tree species to your local growing conditions, including climate, soils and rainfall regimes. Slow-growing, these trees need proper spacing to prevent irregular habits or nude branches as they age.
More than 30 different species of spruce trees grow in the cool-temperate regions of the world, all native to the Northern Hemisphere. Nearly all grow best in deep, moist soils that have a non-alkaline soil pH. Usually, types or species that grow with a tall, narrower habit lend themselves best to creating a hedge or border.
Dwarf-growing selections of spruce trees allow gardeners to enjoy the foliage beauty without growing plants that reach towering heights. Dwarf spruces visually resemble shrubs and often grow even more slowly than wild spruces. These smaller plants might create a hedge or border that is better scaled with your property's buildings, existing trees and acreage.
Spruces grow horizontal to slightly upward-growing branches with whorled needles. New foliage appears each spring only at branch or twig tips, adding no more than 2 to 6 inches of new length annually. For this reason, spruces are considered slow-growing plants, especially when compared to other deciduous trees and shrubs in gardens. If inadequate sunlight reaches spruce foliage, the needles abort, leaving naked twigs and branches that persist. Pruning live spruce branches back to where no needles exist results in stubs, as new buds typically fail to form from the older, woody branch tissues.
The persistent, fine-texture of spruce needles becomes one of the finest ornamental qualities of all spruces. Depending on species, the foliage color ranges from dark blackish green, medium green, blue-green to silvery blue. Trees also bear cones, adding visual contrast with the brown, cylindrical cones dangling from upper branches in fall and winter months.
Proper spacing of spruce trees yields the most attractively shaped mature plants. The dilemma arises whether to place them close together, since spruces grow so slowly, or to plant further apart to allow trees to grow their branches together, creating perfectly formed specimens in a row. According to the spruce species chosen, research the mature width expected to inform you of spacing when creating the border or hedgerow. For example, Serbian spruce grows 70 feet tall but with only a 6-foot to 10-foot spread of branches at the base. Planting these spruces less than 5 feet apart when young creates an instant border or row effect, but expect their branches to intrude on each other as they mature, leading to shading and bare interior branches.
The dense foliage and intricate matrix of branches and twigs within a spruce provides cover for wildlife, especially birds. Hummingbirds in particular nest in spruces, and the wind blockage and overall little habitats created under and around spruce trees favor homes for small animals. In open areas, a border of spruces provides shelter, cover and a natural pathway for nomadic land animals, such as deer.
The main maintenance concern for spruce trees is maintaining an evenly moist soil, especially during droughts or when newly planted trees establish their young root systems. Spruces handle pruning or shearing to create more shapely or formal-looking hedges, but it must only occur immediately after the new spring growth emerges and unfurls. In the Northern Hemisphere, that means the month of June.