Garden Geekery

Quest for Non-Toxic Garden Paint: 1-year Update

So last year I put in four new blueberry plants in raised beds and figured it would be an ideal way to test out a few different non-toxic wood-protection products. It was suggested that I give an update after a year to see how the three products have fared so far.

Left to right: untreated, Eco Wood Treatment, milk paint, beeswax/oil

Left to right: untreated, Eco Wood Treatment, milk paint, beeswax/oil

As a reminder, I used a different treatment on each of the four raised beds: Eco Wood Treatment, milk paint, beeswax & olive oil, and the control (no treatment). In this photo from last year, you can see how all four looked. From left to right: untreated, Eco Wood Treatment, milk paint, beeswax & olive oil.

1-year: similar coloring

1-year: similar coloring

I have to say, I’m a bit disappointed in the appearance of all of them now. After just a year, they all look exactly the same: gray. The beautiful color of the beeswax/oil treatment is gone. I was expecting that for the Eco treatment and the no-treatment, but I’d hoped that the beeswax/oil would at least have retained some of the color. Oh well. Color would have been a bonus for me, not a deal breaker. But it’s definitely something to keep in mind if it’s more important in your garden. Maybe a tinted Eco treatment or milk paint?

Most important is the protection of the wood, which was the whole point for me in treating the wood at all. As a quick test, I dribbled some water on them all. The natural, Eco, and milk paint all seem the same–the water seems to soak right in. But with the beeswax/oil, the water does actually bead a bit. It’s not a perfect bead–it does soak in after it sits for a bit. But the fact that it beads at all makes it different than the other three. It’s certainly hard to tell after just a year if that will actually make a difference in protecting the wood over the long run. But there is a little difference so far. I’ll do some more updates in future seasons.

Water on the untreated, Eco Wood Treatment, and milk paint

Water on the untreated, Eco Wood Treatment, and milk paint

Beading water on the beeswax & oil

Beading water on the beeswax & oil

One note on the Eco Wood Treatment: I had extra left over last year, so I kept it in the paint can in which I’d mixed it. Just a couple of months ago, I was cleaning up my shop and moved the can. The liquid had started to eat through the metal can and was leaking onto my work bench. Um. Now that doesn’t mean it’s something toxic–Coke can eat through some metals if it sits long enough. But it does give me a little pause. We’ll see if it does a fabulous job of protecting the wood or not. But I at least won’t be mixing up any more than I absolutely need for a single application at a time, if I use it in the future.

On another note, I’m extremely pleased with the performance of the plants themselves. They grew fantastically in just a year, and the one on the far left produced a bunch of berries this year. A shout-out to Backyard Berry Plants for their great stock and even more for the great growing and planting tips on their site. I planted these with their recommended “soil-less” method (peat and shredded pine bark) and followed their fertilizing suggestions, as well. The second from the right is actually a replacement this year; that one did die for an unknown reason last year. But the other three look fantastic.

(UPDATE: 3-year update here)

13 thoughts on “Quest for Non-Toxic Garden Paint: 1-year Update

  1. Maury

    When I asked the local woodworker about any exterior preservatives, such as milk based paint, his suggestion to look up “milk paint” led me to your 3 year experiment. Thank you. It’s very clear and informative, and echoes what was told me by a now deceased antique dealer: beeswax, turpentine, and linseed oil (I think) — boiled (?!) it seems he said.

    I use linseed oil whenever I can, thinking it is a natural oil, but it’s expensive. On our 100+ year old siding I use 1/2 oil based primer + 1/2 linseed oil, wait several days to dry hard, then latex paint over. The linseed oil apparently allows a black powdery looking mold to surface each year, but a little soapy bleach water removes that and leaves the latex hard as the first day it was painted, and that’s almost 10 year’s worth of washing and rinsing.

    Any thoughts or experience with linseed oil as a planter preservative?

    1. astevens16 Post author

      Thanks for your comments! I didn’t look into linseed oil too much. It looked like too much of a pain for my needs. It also looks like you have to be careful about what kind of linseed oil you get: raw, polymerized/boiled, or “modified”/boiled. I didn’t want to have to mess around to find exactly the right kind, since it seems like some is safer for food than other types. I think it’s a good preservative, just not something I wanted to mess about with.

  2. Steve

    Great experiment! We’re building our first garden box in NJ I’m researching wood treatment options for Douglas Fir (I have too decided that Cedar is too expensive for this).
    Would you happen to have a 3 year update?


    1. astevens16 Post author

      Thanks! I can certainly provide a 3-year update! I’ll try to do that in the next couple of weeks or so. I could have sworn I had done a 2-year update last year, but apparently not!

  3. kelly

    I’ve been looking for non-toxic garden box finishes and was pleased to come across your website.
    So it appears the beeswax so far may be most water resistant, although I look forward to your 2 year update. In your test, were you concentrating at all on uv-blocking capabilities of the options you tried?

    I’m in S. Cal, so for my outdoor redwood garden boxes my main concern is sun exposure. 4-years of drought and counting here… So, I’m curious if you think the milk paint or beeswax/oil options offer any uv filtering.


    1. astevens16 Post author

      Sorry for the slow response! I’ll provide a 3-year update in the next couple of weeks. I could have sworn I did a 2-year update last year, but apparently not! Guess I was too preoccupied with building our new chicken coop all last year. 😀

      I wasn’t actually thinking about UV filtering at all when I was trying the coating options–just water and rot. Seeing how all the coloring faded in just the one year, I’m guessing none of these options provides much UV protection.

  4. Dan

    I too would love too see how they compare after 2 years! It’s terrible these days with all the ‘bad’ stuff. You can’t even find planters that are ‘free’ of chemicals. Some planters have labels which state, “not for food consumption!”

    1. astevens16 Post author

      Sorry for the slow response! I could have sworn I did a 2-year update last year, but apparently not. I’ll provide a 3-year update in the next couple of weeks!

  5. hlang

    This is great little write up.

    Those beds definitely were made out of Douglas Fir, which is about the only realistic option for building beds on the east coast. It offers moderate durability and is readily available. Western Red Cedar is too expensive in these parts. The reason they turned grey is the effect of Ultraviolet Light. No all natural preservative method is going to have UV protection, and even the expensive deck stains struggle, which is why most have a tint in them.

    Douglas Fir typically holds up well enough to the elements. Left untreated, it may start to crack at the ends where the boards are screwed together. Where it struggles is with ground contact. It will decay at a much faster rate than cedar in that regard.

    Again, this is a great series on what to expect with Douglas Fir garden beds. There’s not a lot of info or photos out there showing how they hold up over the years. Please do update this with photos for 2015. Thanks!

    1. astevens16 Post author

      Thanks! I’m glad you like the post series. I’ll do another update in a few months, when it’s closer to a full two years. I did briefly look into using cedar, but, like you said, it was much too expensive for this type of application. Hopefully these will hold up for a while!

  6. Roger Lightfoot

    Great article on wood treatment. You didn’t indicate if you treated the inside of your boxes. That’s what I’m most concerned with.
    Thanks. Hope to hear from you
    California veggie grower

    1. astevens16 Post author

      Thanks, Roger! I didn’t treat the inside of my boxes, but I could have (and probably should have), since all of these options are supposedly non-toxic.

  7. Pingback: Quest for the Holy Grail: Non-Toxic Garden Paint | Garden Geekery

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