Are we talking fiberglass or pvc piping?

FataMorgana

It's fiberglass. :)

We have some fiberglass rods that are reflective for marking the driveway. After a number of seasons outdoors, they begin to splinter and flake. You can't touch them barehanded else you get fiberglass splinters --- and those are miserable.

I would expect anything used in the garden for containers would have a similar issue. And who wants containers that you cannot work the dirt in. I'd opt for another material.

FataMorgana

Thanks for the info! We are thinking we should paint them with some kind of resin, maybe like fiberglass boats are painted with or something not quite so expensive. I'll have to check with a hardware store. Splintering is definitely an issue!

Whatever you use for coating must be food safe.

FataMorgana

Ugh! It's getting more and more complicated! I'll be researching that. Thanks!

Why the need to contain roots, except for the mints? The rest you listed are not that invasive.

I have planted mint in pots in the ground to attempt containment, but you still have to watch them- runners will go over the edge and attempt to root. They will also go out any crack or hole in the container.

I'm just trying to keep them in a place where I can hopefully keep them weeded and my husband can weed-eat the grass around the tubes. Trying to keep the big weeds like goldenrod, iron weed and grass out of the herbs.

After doing some research, I'm not sure why the coating has to be food safe. I see lots of fiberglass pots for sale and nothing is mentioned about the coating. I see articles about planting herbs and vegetables in them. Apparently the coating hardens when it dries and doesn't give off fumes.

Does anyone have any thoughts on this?

You are what you eat. Chemicals in the soil will be taken in by the plants and subsequently consumed by you. Making sure what you use is food safe especially when using products not originally intended for food growing purposes is always prudent.

FataMorgana

Fibreglass tubs and pots designed for gardening in are not necessarily going to be the same product as fibreglass tubing not intended for gardening. Hence no mention of coating on the garden products. It is taken as read that they will be used for growing and that would include food crops. Your non-garden specific tubes are a gamble regarding the coating since nobody would expect them to be used for crops.