Box Coatings

Hi I am new to SFG.

    I am building some boxes for my wife.  I am making them
    out of "1 by" pine materials.  Is there anything I can coat
    them with to make last longer, that does not affect the plants?

Thanks
Chaz

Depends on how you feel about possible "leeching".
There's a general opinion held by some that using pressure treated or weather proofing/stain can leech chemicals into your bed that can be taken up by your plants and therefore harmful chemicals in your food.  

Personally, I have a couple beds made with pressure treated lumber.  I'm in process of planning a more "permanent" garden solution that will include pressure treated lumber and weather proofing for aesthetic and durability reasons.  That's me though, I've obviously concluded that the risk and level of possible contamination is acceptable.  

So, if you're more concerned about durability than contamination, I suggest using a deck weather proofing.

If you're more concerned about contamination, use a standard exterior paint and paint only the outside, top and bottom sides of the boards, leaving the interior where the dirt goes bare.  

I currently have beds done both ways, my oldest is the pressure treated and it's only about 3 years old, and my oldest "outside" painted ones are only about 2 years old.  All are holding up fine so far.  I think I recall reading in this forum from others that they can last about 4-5 years even unpainted.   

FYI, I just moved a 1 year painted bed this weekend.  It was 4'x4'.  I was able to simply pick the box up and move it and the soil retained it's box shape.  I then of course shoveled the soil over to the new location.  IF your beds are manageable size, and even if you don't paint it at all, I think they would be easy to replace.  Slide old one off and slide new one in place.   

I guess this wasn't much of a help, huh?  Well, my 2 cents.

Thank you!  This was very helpful.
I think I will cover the  outsides as
you suggest.

It sounds like you have been doing this
for a while.

Thanks again.

We're going to line the sides with heavy plastic down to the ground. We're going to use liquid nails as glue between the plastic and the wood. The purpose is to protect the wood from rotting out too soon. We made up this solution. Fingers crossed we're doing the right thing. We're using pressure treated wood at the bottom, where the bed meets the dirt. Then Douglas fir up the sides. I'll post a pic when we get it lined. Good luck with yours.

Thanks for the suggestion, I would like to see the pictures.

RAW linseed oil is safe.  NOT boiled.  A wood box exposed to water will eventually break down, be it 2 years, 5 years or 10 years.  A permanent box would have to be made of stone or brick.  

Zmoore,  You gave me an idea.  When it comes time to replace the wood box, just remove the perimeter Mix, set aside, carefully disassemble the box, and carefully reconstruct a new box around the remaining weed fabric and Mix.

I have only checked one source for
linseed oil, LOWES, but is was boiled.
Do you know of any other sources?
I have a few more places I can check.

Also, I was planning on making the boxes
closed in on the bottom and setting them
on top of cinder blocks, to make it easier
to work with.  I am making them
2 foot by 4 foot.  The question of drainage
came up.  I can drill holes in the bottom,
but I wanted know what a good guide line
would be.  Along the lines of how many and
how big and how far apart.  Or is the idea of
using the cinder blocks not good one.

Thanks for help!

I bought raw linseed oil at an old time hardware store.

Chaz wrote:I have only checked one source for
linseed oil, LOWES, but is was boiled.
Do you know of any other sources?
I have a few more places I can check.

Also, I was planning on making the boxes
closed in on the bottom and setting them
on top of cinder blocks, to make it easier
to work with.  I am making them
2 foot by 4 foot.  The question of drainage
came up.  I can drill holes in the bottom,
but I wanted know what a good guide line
would be.  Along the lines of how many and
how big and how far apart.  Or is the idea of
using the cinder blocks not good one.

Thanks for help!

 When elevating my beds I added a plank floor. Leaving  a 1/4 inch space between, and a 3/8 inch hole in the middle of each square. After adding 2 layers of a quality weed barrier I flooded the bed with water to check for drainage..it worked nicely...After one season in use it all worked out.

Thanks a lot for the ideas for drainage, and
for the time in taking the pictures.  It is very
helpful!

Chaz, Cinder blocks will work great for elevating 2' x 4' beds. 3/4" plywood flooring with 1/4-3/8" holes in the center of each square and one in each of the 4 corners recommended in All New Square Foot Gardening book. Line with weed fabric to prevent loss of Mix out the drain holes.

Chaz wrote:Thanks for the suggestion, I would like to see the pictures.

Our SFG is 3' high. Our son had a whole roll of super heavy-duty plastic from a boat shop he bought out, so he donated it to our garden project. It should last a long time and be almost puncture-proof.

Chaz, welcome from Coastal NC.
You have asked a question we all have asked ourselves and others.

To give you some perspective...My first boxes were untreated pine 2x6's set on the ground with weed fabric underneath. I used them for a couple of seasons and then they just sat there for several years.
Here is a picture of them when I finally pulled them up:


Here is a link to a thread where I have more pictures of the old boxes...
SFG - North Carolina

I have since gone to using elevated table top beds. One is a 4x4 and I used untreated 2x8's for the sides and untreated 3/4" plywood for the bottom. I painted everything except the inside then lined it with 6 mil plastic and weed cloth.
Adventures in Table Top

I also made some 2x8's and used untreated 2x4's painted on all sides except the inside. for the bottoms I used wire shelving I got for free from work and put styrofoam down also before covering with plastic and weed cloth.
2x8's with Wire Shelves and Styrofoam

Those are the things that I have done and so far so good.

I am looking into using some PVC sheet for the bottom and sides on my next box. The board(s) are a bit pricey but if they never need to be replaced, then the cost will be worth it.
PVC Panel
They also sell some PVC for trim that is sized like standard 1x's. I am thinking that since we use PVC for drinking water, PVC for the sides and bottom would be fine
Vinyl Trim

Good luck

PVC piping is approved for drinking water. PVC trims may not be. Check their specifications if you want to stay with water grade.

I spoke to the folks at Home Depot about this because I needed to paint or stain mine for aesthetic reasons (it's in the front yard and live in HOA). They claimed that once exterior latex paint dries, it doesn't go anywhere. I spoke to John (the guy that does the Growing Your Greens channel on YouTube) and he pretty much agreed that it wouldn't leech. He suggested low VOC exterior latex paint outside and if I was REALLY worried to use ECO (I'm sure the oils mentioned would work too) to "seal" the pores. I just painted mine. Will it rot from the inside? Yes, but I think it will last years with that thick outer coat of paint.