Don't Use Horse Manure When Planting Colorado Blue Spruce

Why Aged Horse Manure Harms Young Spruce

Planting 20-inch Colorado blue spruce? No fertilizer in the planting hole – especially not horse manure.

Risks of Manure at Planting

• Root burn: High ammonia/salts damage tender new roots.
• Nitrogen excess: Forces weak, leggy growth; reduces cold hardiness.
• Color loss: Over-fertilization turns blue needles green.
• Weed seeds: Even 8-year-old manure can sprout weeds.

Proper Planting Protocol

1. Dig hole 2× root ball width, same depth.
2. Backfill with native soil only – no amendments.
3. Water thoroughly to settle.
4. Mulch 3 inches (pine straw, wood chips).
5. Wait until second spring to fertilize lightly with 10-10-10.

Use the Manure Elsewhere

Compost it fully, then spread in vegetable/flower beds where nutrients are welcome and roots are tougher.

Spruce seedlings from nurseries already have optimal fertilizer. Adding more does harm, not good.