Wood for grow boxes

[Russell D.]

I just got off the phone with a very helpful young man at my local Home Depot. I was gathering info from him on the prices of redwood, cedar and composite planking that I want to make grow boxes from. When I mentioned to him that I was going to make grow boxes he suggested that I use treated lumber, quickly adding, as if he anticipated my protest, there is no longer any arsenic used in the treating process and nothing is used that would be harmful.

I would appreciate any thoughts on this. I'm still a bit hesitant about using treated lumber for grow boxes for vegetables but it would sure save a lot of money if I could.

What do you think?

Russell

[Gary & Karen]

I have seen cedar boxes that was 25 years old.

Gary

[Frank Logullo]

I don't "think" I "know" that there are still some nasty chemicals used in treated lumber. I would definitely not use for vegetables. Frank

[Phisherman]

I would avoid using PT wood anywhere where it may touch food. Working with PT wood is just plain nasty (the dust is not good to breath, the wood crumbles, and it twists and turns as it slowly dries, etc). I'm not totally against PT wood, as I built two trellises, a park bench, and mailbox post from it.

For vegetables a good choice is cypress. You could use white oak, cedar, redwood, teak whichever is lowest price. These are all good outdoor woods. Before filling these with soil, line them with galvanized metal, aluminum, copper, plastic, tile, or plastic. The boxes should be able to drain quickly without having "wet feet" for extended periods.

[Travis]

Or you could use:

[bamboo]

The sapwood of cypress is little better than common pine. What you want is heartwood.

[fran]

Thanks for the link

[bamboo]

The sapwood of cypress is little better than common pine. What you want is heartwood.

[Doug Kanter]

Definitely NOT treated lumber. You've gotten some good suggestions already. I'll add another. I made some accesories for my boat (rod holder, etc) using

3/4" birch plywood, and slathering on lots of exterior-grade polyurethane. These various pieces of "furniture" are constantly exposed to the elements, but they're holding up very nicely after 5 years. Granted, they're not exposed to gritty soil and sharp tools like trowels, but if you dinged them during the growing season, it would take very little work to rinse them out and slather on a quick touch-up coat of poly. It's the insides that should take a beating, not so much the outsides.

Just be sure to apply the polyurethane a couple of weeks before use. I don't care WHAT the containers say about "ready in 24-48 hours". It was at least a week before I noticed that the smell was completely gone.

[Timothy]

Good day Russell, unsure what type of 'grow boxes' you wish to have or their size. If these boxes will be more like raised beds, then I would suggest that you look at stone. The allen block, diamond block type. These will cost a bit more in the begining, but they will pay for themselves in the long run for sure.

If your thinking smaller, then I would recommend trex composite. Trex will again cost a bit more, but will last 15+ years in the ground with no problems. It's paintable and screw'able.

[Mark Anderson]

I made my first two 2x8x1 boxes out of that Home Depot treated lumber. So far, after 3 years, the boxes are still structurally sound and I didn't have to do any maintenance on them. I definitely wouldn't grow veggies or edibles in these boxes. Those boxes are for wildflowers.

Those 8' 1x6 planks of treated lumber aren't cheap though. In my area they're like $8 each or $1/lf. In my experience, Home Depot's lumber is expensive. For $1/lf I can buy 1x12 untreated quality pine boards from a lumber yard but then the wood needs to be painted with a durable paint. Three years ago I used 9 of those 1x6 Home Depot treated 1x6 planks for each box plus a bunch of treated 2x2s and 1x2s for framing. Each box cost me about $100 if I recall correctly. I've since thought of ways to cost reduce this.

As someone else pointed out, you can get a 4x8 sheet of birch plywood (3/4") for around $30 (in my area). That stuff is pretty excellent wood and even cheaper than pine boards but you'll need to either paint it or treat it yourself to keep it from succumbing to moisture.

[Richard Cline]

I have some exterior plywood that has been outside for twenty years nd it is still going strong. It would be better if it had a good paint job but plywood is superior to many other kinds of wood. It is hard to beat the price of plywood.

Dick

[garrapat]

The same applies to Redwood, the white sapwood decays quickly in contact with soil. Construction Heart is the lowest grade I would use for planter boxes