A cautionary note about over fertilizing.

The benefit of this blogletter has been to see how differently people approach their walnut growing. I have been thinking about the possible responses to the fertilizer section of the last blogetter and have decided that a note of caution is in order before you start throwing around large amounts of fertilizer.

In particular, it bears repeating that one of the quickest ways of killing a tree is to give it too much Boron. When we first moved in we were burning quantities of boric treated off-cuts in our wood burner. Under the down pipe from the roof gutter the grass started to die. The boron in the smoke had settled on our roof and was now killing my grass. Even on this deficient soil you can apply too much. Boron is toxic stuff and needs to be treated with respect. In the absence of any obvious symptoms, even applying the usual recommended dose of half a teaspoon of Boron per tree may be too much.

Other types of fertilizer can be a problem in excess too. My father once bought a citrus orchard cheaply because the previous owner had put on too much chicken manure. That contained excess potassium, which caused magnesium deficiency, which he did know how to correct, so he put it on the market.

It might NOT be a good idea to apply a lethal dose of fertilizer to your WHOLE orchard. But doing something beyond your usual practice to A tree to see what happens could be interesting. Let us know how you get on.

Your paranoid blogger