Borax and Copper Sulfate - Safe for trees?

[Chris Jacobie]

Hi,
I thought it might be helpful to ask this in its own thread for future searching.

Morph just analyzed my soil test results and my copper and boron are low. The recommendations are 20 Mule Team Borax and Copper Sulfate.

I've seen that Borax can be used as an herbicide and kill desirable vegetation. And copper sulfate is commonly used to kill tree roots.

I have a mature sugar maple that's struggling right now so I'm trying to get it healthy.

With a tree in the lawn, should I avoid boron and copper applications altogether? Or at least wait until the tree is healthier?

Thanks!

[turf_toes]

Over applying boron can basically make your soil unsuitable to grow anything.

It’s one of the reason I’ve never played with micronutrients. If it were me, I’d avoid it. But again, I tend to play it safe. Morph or Andy might have their own thoughts on the topic.

[Chris Jacobie]

That's spooky. Morph recommended micros based on my soil test but I know a lot of people don't fool with it. I think I'll just stick with organic fert focused on macros plus some fudgy things like kelp and molasses and all that to get some trace elements in there.

[turf_toes]

Take that for what it’s worth. I don’t doubt that tweaking micronutrients can improve your lawn.

I don’t doubt that Morph gave you good advice on the rates to apply.

I just don’t know that I trust myself enough to get the application right. Again, it’s a choice everyone needs to make for themselves.

[Chris Jacobie]

Oh yeah, I'm sure the rates are spot on but I don't trust myself to get the app right either. That's why I like organics lol.

[MorpheusPA]

Boron and copper are both required for every plant on the planet. Bork it up and you just rendered your soil completely sterile.

However, the amounts we recommend aren't easily in the "borkable" range. We're usually targeting 0.5 to 0.7 PPM for boron, 2 PPM or so for copper. Sterility starts around 3 PPM for sensitive plants for boron (most trees and grasses not being particularly sensitive), and very very much higher for copper (copper depends more strongly on pH as well).

Consider the simple fact that I use higher apps than I recommend and have no issues in my gardens, which are more sensitive than the grass. Even in the smoke from Canada, a five week drought, and noon sunlight, this was the garden: