The lone voice of horticultural reason

“Bone meal is good to add to soil when planting trees and shrubs”

Rummage through many gardener’s garages or potting sheds, and you’ll often find a bag of bone meal. Many gardening books and myriad magazine articles published today laud the merits of bone meal as a soil additive at time of planting. You’ll certainly see it for sale at all the nurseries, right alongside the bags of fertilizers, this one, lone, super-additive that we are led to believe is worthwhile to add to the soil when planting trees and shrubs.

It isn’t. Bone meal is a leftover from the bygone era when all-purpose organic and synthetic fertilizers weren’t available in bags at nurseries. Bone meal was a nice source of phosphorous, the middle number on a bag of modern fertilizer (N-P-K, nitrogen, phosphorus, potassium). Before N-P-K was sold together in bags, gardeners had to make due purchasing each of these nutrients separately.

Modern bone meal has an NPK of around 0-12-0. It also contains a modest amount of calcium, one of the important micronutrients. However, both phosphorus and calcium are usually adequate in soil before you plant anything. If you plan on fertilizing with a tree and shrub, or all-purpose fertilizer, your soil is going to contain ample phosphorus. If you’re not, the soil is still going to contain ample phosphorus.

Excess phosphorus, however, is very harmful to plants. It weakens and can destroy formation of the mycorrhizal fungi in a plant’s root system that is essential to help the plant draw water and nutrients.

Bone meal? Too much of a good thing. You never need it. Then why is it still for sale, you ask? Because if people will buy it, the gardening industry will sell it. What, are you new to this site?

Don Engebretson
The Renegade Gardener