How Deep to Plant a Colorado Blue Spruce

Planting Stock Types

• Colorado blue spruce trees transplant well as long as the root ball is not damaged or too significantly reduced while being dug at the field nursery. Seedling and bare-rooted spruce trees transplant poorly and often die in the process. For best results, nurseries grow and sell Colorado blue spruce trees in containers or as dug-up, balled and burlapped (B&B) plants. The rigid plastic or nylon planting bag containers allow tree roots to grow undisturbed and lessens harm during the planting process. B&B trees have been root-pruned and watered sufficiently to sustain their roots in a compact root ball.

Planting Depth

• Plant Colorado blue spruce trees so the top of the their root ball is slightly above soil grade. Examine the top of the root ball, especially in B&B plants, and brush away soil to find out exactly where the root flare is. During digging, soil may accumulate atop the root flare and make the root ball seem taller than it truly is. Dig a planting hole so that when the container-grown spruce tree is place in it, that the top of the root ball is at or slightly above the soil line. Alternatively, make the hole deep enough so that the root flare and root ball top is 1 to 3 inches above the garden soil level.

Soil Types

• If the garden soil is naturally porous and crumbly in texture, water drainage is sufficient and there's no concern for the Colorado blue spruce's future health. Sandy and loam soils with organic matter constitute ideal soil environments for planting and spruce tree growth. The root ball may be planted slightly deeper in sandy soils, but the top of the root ball should be at soil grade -- the soil line at the top of the planting hole. Compacted loam and all clay soils drain water slowly and create oxygen-depleted conditions for tree roots. Always plant spruce trees high in the planting hole in clay soils. As much as one-third of a blue spruce tree's root ball can remain above grade when planting in heavy clay soils. Taper backfill soil up to the top of the root ball to create a planting berm at the base of the spruce tree.

Post-Planting Tips

• Once planted, water the planting area to remove air pockets and naturally compact the soil so roots come in direct contact with soil particles. While it may look awkward at first to see the root ball of the Colorado blue spruce slightly above the soil grade, this ensures good drainage and health of the root flare. Place a 2- to 3-inch layer of organic mulch around the base of the tree. Keep the mulch 2 inches away from the trunk, but layer it out from the trunk in all directions, at least 24 inches outward. The mulch deters weeds, retains moisture and keeps the soil cool for roots to grow their best.