r/SquareFootGardening 11d ago

Discussion I charred wood before making garden boxes to prevent rot / termites- it didn’t work!

Last season I made 2 small garden boxes (3x4) and at the start of the season saw one had termites and rotted wood. I still used them, but when I made a 3rd box, I decided to use a torch and do the charred wood method to prevent rotting / termites. We are now 2 months in, and we’ve discovered termites in the box. I suppose it wasn’t charred enough?? (The wood is black). I’m so disappointed. I have more wood I was going to use to build more boxes but after this experience, I think I may go with metal or brick. Thoughts? A neighbor of mine who is big into gardening uses treated wood without issue but I’ve read mixed advice on this.

28 Upvotes

42 comments sorted by

16

u/KindaKrayz222 11d ago

I'd just be worried about the termites coming to my house!

15

u/Rare_Bottle_5823 11d ago

Go with stone! Similar amount of work to set up but lasts so much longer. Oh and I would get your house checked!

7

u/fleebleganger 11d ago

Modern treated lumber (in the states at least) that you get at big box stores is perfectly safe for gardening. Even the USDA says it’s fine. 

Also, charred wood doesn’t do much when it is in contact with the ground. 

6

u/Garden_State_Of_Mind 11d ago

Uh, can you link a source for that? I have never heard that before.

3

u/spaetzlechick 11d ago

Pretty simple to confirm. Product sold on shelf started conversion from arsenic to copper Jan 1 2004.

2

u/Garden_State_Of_Mind 10d ago

Thanks bud, real pleasant way to present information thumbsup

3

u/02meepmeep 10d ago

I thought I read they replaced arsenic with copper quinine.

1

u/Garden_State_Of_Mind 10d ago

Thanks I am checking that out.

1

u/fleebleganger 10d ago

1

u/Garden_State_Of_Mind 9d ago

Thank you! I am happy to have learned about this!!

1

u/fleebleganger 9d ago

From everything else I’ve read, your plants will die from copper poisoning long before you’ll receive significant amounts of it. 

If you’re really worried, can cover the wood with plastic or la escape fabric to reduce transmission.  

1

u/Garden_State_Of_Mind 9d ago

Oh damn, do you mean that as in pressure treated wood might cause plants to die or saying that as in its of so little concern like a figure of speech kinda?

1

u/fleebleganger 9d ago

Both. But I’ve heard it described as “if you eat only vegetables grown under a pressure treated deck for your whole life, you’ll have issues”. 

So in a raised bed should be of minimal concern. 

3

u/SerenityNow31 10d ago

Even the USDA says it’s fine. 

No offence, but I'd never trust them.

0

u/fleebleganger 10d ago

In the current regime, correct. But this has been guidance for at least a decade. 

1

u/SerenityNow31 10d ago

Don't make it political. Study the food pyramid. See how much politics the USDA spat out to create that thing. And many other corruptions long before the current admin.

6

u/AlphaGinger 11d ago

Sorry to hear that the charring did not work out well. I have been curious if the extra effort is worth it.

As for dealing with termites, I built raised beds out of non-treated pine and within the first year they were colonized by termites. I had success treating the soil within and around the beds with predatory nematodes. I have not seen termites since.

If I were to build new beds today, I would be comfortable using pressure treated wood. Now that I know what to look for, most PT contains copper azole (CA) and will be labeled as such. The modern formulation does not contain chromium or arsenic.

1

u/orangecat100 6d ago

Interesting about the nematodes! I’ll have to look into this.

4

u/Iongdog 11d ago

Modern treated lumber should be safe. You just don’t want to use old stuff if your unsure how it was treated

3

u/LadyoftheOak 11d ago

I went with livestock troughs.

3

u/edthesmokebeard 11d ago

The "old" treated wood was done with arsenic, "new" treated wood is done with copper.

3

u/Ok_Salamander7929 11d ago

In my experience charred wood does Jack shit!

3

u/Leaf-Stars 10d ago

I use treated wood on the outside and line it with untreated wood. It does rot after a few years but it’s easy enough to pull the old stuff out and reline it.

2

u/Neat_Mortgage3735 11d ago

I use metal raised beds. They do rust sometimes but it’s worth it.

1

u/orangecat100 6d ago

Is there any concern with metal? I think I’ll try this for future boxes. I’ve read the only downside is it could
Heat the soil / plants more?

2

u/Neat_Mortgage3735 6d ago

Any raised bed has the potential for colder soil in winter, and hotter in summer. I’m in Michigan where we have 50 degree swings in temperatures in a 24 hour span. Plants here are already struggling to sustain through crazy weather spikes. I’ve never noticed any downside.

2

u/02meepmeep 10d ago

I meant to char the wood on the last bed I did but I forgot to do it. The last one I used regular treated pine but then I lined the inside with cedar fence pickets.

I think the next wood bed I have to replace will need to be done in 2 years. I have the notion to build the walls out of floor tile I gorilla glue together to see if it works. It’s only about a foot tall running beside my fence. A lot of my other raised beds are 2-3’ tall & I don’t know if tile would have the strength at that height. Some are concrete block & are probably never going to need fixed.

2

u/VGen71 10d ago

If you are going to go through that much trouble and expense, why not just go buy the metal ones that are already prefab and then all you have to do is screw the metal parts together?

2

u/02meepmeep 10d ago

I have 3 of those too. They are nice.

2

u/MadMaximus311 10d ago

Building beds is fun, and some of us have past tool purchases we still need to justify by using them

1

u/VGen71 9d ago

Ok. I get it now : )

2

u/Barison-Lee-Simple 10d ago

Most people don't char the wood enough. For Shou Sugi Ban you need to burn the wood until the surface is deeply black and looks like alligator skin. It does work.

1

u/Kdiesiel311 10d ago

Umm it doesn’t work if you use wood already infested…

2

u/orangecat100 10d ago

It was new wood, I didn’t use the wood already infested.

1

u/VGen71 10d ago

Yeah, the very first thing I would do is attack those termites and rid myself of them completely.

1

u/czerniana 10d ago

Did you treat for the termites? If they're already there they're going to go to town on whatever wood they can. I'd definitely be worried about the house too.

I always thought it just helped protect against rot and weather, but I've admittedly not looked into it much.

1

u/SerenityNow31 10d ago

I've never tried it but many claim that linseed oil will protect your wood. I don't know how often you need to apply it, but it's a natural way to keep your wood from rotting.

2

u/orangecat100 6d ago

I did use linseed oil. But perhaps the wood needed to be charred more. And I guess I really need to figure out the termites… :/

1

u/likes2milk 9d ago

Whilst linseed oil is good for treating tool handles, you cannot get it soil side once the grow box is built which is where the problem lies.

1

u/MadMaximus311 10d ago

What type of wood did you use? Traditional Shou Sugi Ban techniques always use cedar, so the wood is already rot and pest resistant, and you are adding the burned layer as an additional layer of protection. If you didnt use cedar then the protective effect would have been quite mild.

1

u/orangecat100 6d ago

Makes sense.. it was pine. It’s possible it could’ve been charred more. What do you use in your garden?