Copper for root pruning (in air layers?)

[Kelby]

Some of you may be aware, copper has the effect of stopping root growth. Some formulations of copper (most commonly copper hydroxide, but also carbonate and sulfate) have been used commercially in a paint on the inside of pots to prevent root circling and promote a more dense root system. There was a product called Spin-Out available for this, but doesn't seem to be sold anymore. This is same basic idea as air pruning pots/grow bags.

I was pondering if this would useful in air layering. I have had the problem where a layer seems well rooted, but it turns out it's just a few roots going round and round the container. Winds up being weak and taking longer to recover. So here's the mad scientist idea: could the application of a copper product to the inside of the air layering container (I usually use empty water bottles) promote a more branched and sturdy root system? The downside would be that you couldn't see inside the layer without opening it.

Here is a little info on doing it at home: http://faq.gardenweb.com/discussions...iner-gardening

Just a warning if anyone is planning on Googling more info, many of the first links on Google lead to marijuana growing websites, so NSFW.

[tyro]

Don't know about the copper,never tried it.In regards to air layer root growth I've found this shape container to give me the best results.The roots seem to be funneled downward and air prune themselves.

[starch]

Hi Kelby. I have used copper hydroxide paints on my pots for a couple of years now (I am using MicroKote). They definitely work! I recently up-potted a citrus that was in a 5 gallon pot for WAY too long (>6 months longer than it should have been). The pot was painted with MicroKote. *No circling roots*! The root structure was very thick and fibrous and just beautiful. This stuff definitely works.

MicroKote is pretty expensive. Here is a recipe if you want to make a DIY version of Griffin Spin-Out: http://tropicalfruitforum.com/index....4966#msg124966

[Kelby]

Nice! Thanks for sharing!

[ThaiFigs]

I get a brush-like root effect in air layers by making long scratches to expose the cambium. I paint the long scratches with rooting hormone. I wrap with tin foil to prevent cooking the roots. No need for copper paints in an air layer, which would obscure your view of the progess.