Plant Trees without Amending the Soil

Plant Trees without Amending the Soil
Photo: Alex Indigo, Flickr

Forget the old technique for planting shrubs and trees that you learned as a kid. You were told to amend the soil removed from the planting hole with compost, organic matter, or fertilizer. Some gardeners even replaced all the soil with quality topsoil. But let me share a secret with you: that’s not the best approach!

Studies conducted by renowned American tree expert Dr. Alex Shigo have shown that when the soil in the planting hole is better than the surrounding soil, the roots tend to stay within that area, circling and eventually girdling the plant. This can lead to the plant being strangled and struggling to thrive.

Instead of amending the soil, it’s best to backfill with the original soil, without adding any amendments like fertilizer, compost, or manure. By doing this, you ensure that the soil quality remains consistent throughout the planting area. The roots will then naturally extend out in all directions, just as Mother Nature intended.

However, if you’re dealing with disturbed or poor-quality soil, there is one exception. You can apply mycorrhizal fungi to the plant’s rootball. These beneficial fungi help improve root growth. Unlike fertilizers, which encourage roots to stay close by when added to the planting hole, mycorrhizal fungi promote root spreading and expansion.

Tree and shrub roots tend to remain in the area with the best soil, eventually girdling the plant.
Photo: distinctivetreecare.com

If you want to improve the texture or quality of the soil, it’s best to do so after planting. Apply compost or fertilizer throughout the entire root zone, extending beyond the drip line. This will encourage the roots to spread outward in search of the added nutrients. By improving the soil in this way, you not only benefit the tree or shrub you’ve planted, but also enhance the growth of all the plants within that zone.

Remember, when it comes to planting trees and shrubs, sticking to the original soil is the way to go. Avoid the temptation to amend the soil in the planting hole, and let nature take its course. For more tips on tree planting and gardening, visit Tips Tree Planting. Happy gardening!

To improve the soil around a tree or shrub, apply compost or fertilizer throughout the entire root zone, extending beyond the drip line.
Photo: laidbackgardener.blog