wood for SFG

When my husband & I went to Lowe's to buy the wood for the SFG, I didn't explain the need for untreated wood. I walked away and when I came back he had already had pre-treated wood cut. I asked the employee what it was treated with and he said basically salt and pressure but he really didn't know. Now I am second-guessing this wood...do you think it will be ok to use? I felt bad telling my husband about it at the time but I don't want to compromise the veggies. Thanks!

I am not sure what wood is treated with either. I built a compost tumbler. I used treated wood for the base. So, if you decide to get untreated wood for your garden, you can use your treated wood to make your own compost tumbler! It is a lot of fun, keeps your compost tighty so the neighbors don't complain.

Hi,
I live in the PNW. I wouldn't consider using anything but pressure treated wood for my beds. A few years back, they stopped selling the old CCA treated wood, and replaced it with the all new and improved treated wood, that supposedly is safer because the main preservative is copper.

I just line all my boxes with 6 mil plastic and don't worry about it.

On the plus side, your treated lumber will last much longer than the cheap pine. (Which I believe is why boffer will only use it.)

I wouldn't use that for SFG, I just read that you shouldn't even touch it because of copper arsenic etc etc that can get into your system. I just read the Toronto fact sheet on pressure treated wood and I don't like it much.
Here is one of the warnings:
Fruit and vegetable garden boxes made of CCA-treated wood should have a plastic lining on the base and sides of the box to separate the wood from the soil.
Take a look:
http://www.toronto.ca/health/factsheet_ptw.htm#03

You know, reading this made me realize that I never had these allergies and breathing issues until I sanded the deck on the back of my old house 9 years ago, I remember breathing a bit of the pressure treated stuff in and now it's like I have asthma.

ayanefan wrote: I just read the Toronto fact sheet on pressure treated wood and I don't like it much.
Here is one of the warnings:
Fruit and vegetable garden boxes made of CCA-treated wood should have a plastic lining on the base and sides of the box to separate the wood from the soil.

Here in the States. CCA wood is no longer sold for residential purposes. The newer kind is considered safe for gardening beds. Texas A&M did research on the older CCA treated lumber and found no leaching that got into plants -- but I can't find the link right now.

Thanks for all your responses!

One more question...to those that line their beds with plastic...should I worry about any type of leaching from the plastic? Is there a specific kind of plastic to purchase? I am so sorry for asking such basic questions. Gardening is brand new to me!

Also, what about drainage? Should I do anything to the plastic to make sure there is adequate drainage? If I line the beds with plastic does this mean I can omit the weed cloth? Uggh! Maybe I should just go back and buy the untreated wood Thanks so much!

HI

6 mil (mil is thickness) is just thicker than say painter's plastic. It won't tear as easily. It can be found at any big box store; it's commonly used by contractors. Or to save a little money, one could use 4 mil and be a little more careful. Heavier plastic garbage bags would work too.

I use it just to prevent soil from touching treated wood, which for me is just on the sides. For an open bottom box, it's recommended that weed barrier, newspaper, cardboard etc be used to separate the mels mix from native soil, for weed control and to prevent intermingling.

I've never given soil contact with plastic a second thought. Although I have no doubt, that somewhere out there is a 'study' that claims it 'could' be a potential problem.

The link to the Toronto fact sheet is broken, but here is the update: http://www.toronto.ca/health/pdf/factsheet_ptw.pdf

Steve, have you had any problem with your lining and mold? My students (a church youth group) entered their SFG into the Foundation contest this summer and got disqualified purportedly because of the plastic lining. I consulted with the local Extension service per Mel's advice and searched the forum boards here (using this and other threads on pressure-treated wood for reference) before instructing them to proceed with the conversion of their established raised beds, so I feel partly responsible for their success, or seeming lack thereof.

We don't have an Extension Agent on staff ATM, but the Master Gardener who consulted with me said that lining beds with 6 Mil Plastic is the current accepted practice and strongly recommended we do the same, saying there was no need to tear them out and start over as long as this procedure was followed. I've been waiting for weeks now to hear Mel's take on the issue (Victoria was the one who mentioned mold as a potential hazard, but was uncertain about the current recommendations.)

I'd really like to be able to explain Mel's position to the youth group and church leaders who relied on me as the SFG "expert" on the subject. They're still confused as to why they were eliminated from the competition.

Here are some photos of their Hero/Gratitude Garden project: https://squarefoot.forumotion.com/t14034-square-foot-hero-gardens#142486

Let us know when you hear back from the Foundation. BTW, this thread is over two years old and not all members are currently active. I am not sure you will get a response to your question. Good luck.

Yep, I knew it was an older thread, but see that Steve (boffer) was still busy posting this past summer -- so figured it was worth a try. Thanks for the quick response ~ it's always nice to know someone's listenin'! I've been putting off asking here on the forum, thinking that I'd hear back from Mel or Victoria, but the squeaky wheel gets the grease!

As a certified teacher, it's important for me to understand this controversial issue fully, not only for this church group, but also for any future students or clients who may have old beds needing conversion. They trusted my advice (Mel had just put out a notice that we should consult our local Cooperative Extension Service when this question arose,) so I hope to get some answers soon and will pass it along when I do!!

Why did your students use a plastic lining?

If you have a question for Mel, you would probably have a better chance of response contacting him on his own website as he isn't an active member here:
http://www.melbartholomew.com/

Also, the foundation website has a teacher support form you can fill out and perhaps get answers that way as well.
http://www.squarefootgardening.org/home#!gardening

Boffer decided to take a break from the forum.

Hi Camprn, the church had constructed raised beds for the Youth group a few years before I came along to introduce them to Square Foot Gardening. They used pressure-treated landscape timbers donated by a church member. They do not know how old the timbers are or what chemical substance was used in the treatment.

Good to hear from you again, RoOsTeR! I've already contacted Mel at two different addresses (including the old one which he monitored personally when I first became a Certified Teacher back in '09) plus a couple of times on the blog, where Mel first replied to me when I asked about the missing Church category, and he discovered the contest entry(ies) had been misplaced.

I've also contacted our Teacher Coordinator, Belinda Jensen, not to mention multiple (unreturned) calls to the Foundation office over the course of a month or more, and finally got through to Victoria, as mentioned above.

Victoria confirmed that the Foundation has converted community gardens originally constructed with pretreated wood, but explained that they decided not to address this issue (controversial as it has been in the past) and just filled up the boxes with Mel's Mix. She was not aware of the current recommended practice of lining the beds with 6 Mil black plastic, and planned to consult with Mel when I explained the situation and need for further understanding.

When I didn't hear back as promised, I emailed again and yesterday, found a voicemail on my machine from office staff, repeating all (mostly incorrect information, like the church garden has no grids) that had previously been discussed by email with Mel's assistant prior to my call to Victoria. Still waiting for an answer to this question from Mel, as no one else seems to get it, and it's clear that he has yet to see the original contest presentation or he would have seen the grids! LOL [See link to Hero Gardens above]

This kind of miscommunication kept my application for certification lost in limbo for a full year 'tween new interns and office staff turnover before it caught up with Mel. Had a devil of a time getting through to him back then, too. When Mel finally discovered what happened, he apologized profusely for the mix-up and granted my certificate retroactive to the date it should have been awarded back in 2009.

Can't help but think the same thing happened to the church contest entry, because this just isn't like the Mel I've come to know. I've been out of circulation since the new forum came online (my son took ill and passed away) and see no one from the Foundation (including Mel) is active on the forum.

That comes as no surprise, as Alan set up the original SFG forum for Teachers and Students to connect years ago. After waiting so long to hear from Mel, I decided to post here to see if Boffer or someone else with lined SFGs might have some information on the mold question raised by Victoria. Bummer to hear he took a break right before I got back in the saddle! C'est la vie... Thanks for letting me know!

Wow! A long haul.

So, to progress about the question of mold in the garden, I suppose the foremost question in my mind is, have you a mold problem in the garden at this time? If you do, have you taken a sample and sent it for analysis to determine what kind it is?

Seems to me that would be the next best step in this journey.

After determining what type of mold is present, does it actually have heath risks associated with it? And do these health risks outweigh the possible health risks of the treated lumber?

Perhaps a garden rebuild would be in order if the answers to those questions is yes.

Hello again, camprn ~ I'm beginning to feel like old friends! And, yes, it has been a long haul over the past three years, but I'm due for a comeback!

Not even Victoria's sure that the mold issue is a concern with the 6 Mil liner, as she was thinking we were using some kind of thin plastic for a weed barrier instead of the landscape cloth. At the time we spoke on the phone, Victoria had not seen the garden, either. That's why she had planned to consult with Mel to clarify and get his thoughts on the subject.

Neither the Master Gardener nor the Toronto Fact Sheet mentioned mold as a potential issue with using the liner, and I know that there are others who use plastic boxes or tubs with drainage holes for their SFGs, so I don't see the difference. Mel always encouraged us to be creative and frugal with our gardens, and this is no exception.

Besides that, the church invested quite a bit of effort and money into converting these beds as the fall planting season rapidly began to pass them by waiting on the Foundation to respond; rebuilding at this point is not an option, financially or otherwise. I did suggest overlaying the old bed with a plywood base and building up, and if mold does prove to be a problem, that might be a consideration down the road.

Somewhere in the blogs or galleries is a photo of Josh Greene, or another certified teacher, successfully using a large plastic SFG box on legs -- their garden was vast and mostly wood boxes of different shapes and sizes, but this one was featured prominently with the others. I came across it this summer, but haven't been able to find it again since this issue arose. Did come across the follow-up blog article to Mel's recent newsletter recommendation on getting advice from your local Extension Agent & Master Gardeners: http://www.melbartholomew.com/your-friend-the-ag-agent/

Enjoy your day, mon amie ~

Steve, have you had any problem with your lining and mold? My students (a church youth group) entered their SFG into the Foundation contest this summer and got disqualified purportedly because of the plastic lining. I consulted with the local Extension service per Mel's advice and searched the forum boards here (using this and other threads on pressure-treated wood for reference) before instructing them to proceed with the conversion of their established raised beds, so I feel partly responsible for their success, or seeming lack thereof.

As a certified teacher, it's important for me to understand this controversial issue fully, not only for this church group, but also for any future students or clients who may have old beds needing conversion. They trusted my advice (Mel had just put out a notice that we should consult our local Cooperative Extension Service when this question arose,) so I hope to get some answers soon and will pass it along when I do!!

I guess I'm at a bit of a loss here as to what the problem or question is exactly? Are you looking for an answer as to why your beds were disqualified from a contest put on by the foundation? Mold? Use of treated wood? I'm having a bit of a head scratcher here.

RoOsTeR wrote:

Steve, have you had any problem with your lining and mold? My students (a church youth group) entered their SFG into the Foundation contest this summer and got disqualified purportedly because of the plastic lining. I consulted with the local Extension service per Mel's advice and searched the forum boards here (using this and other threads on pressure-treated wood for reference) before instructing them to proceed with the conversion of their established raised beds, so I feel partly responsible for their success, or seeming lack thereof.

As a certified teacher, it's important for me to understand this controversial issue fully, not only for this church group, but also for any future students or clients who may have old beds needing conversion. They trusted my advice (Mel had just put out a notice that we should consult our local Cooperative Extension Service when this question arose,) so I hope to get some answers soon and will pass it along when I do!!

I guess I'm at a bit of a loss here as to what the problem or question is exactly? Are you looking for an answer as to why your beds were disqualified from a contest put on by the foundation? Mold? Use of treated wood? I'm having a bit of a head scratcher here.

Regrets for the confusion, RoOsTeR! I was just explaining to camprn why I asked Steve (boffer) directly if he'd had any mold issues with his plastic lining, because this is one of the reasons Victoria cited for the church's garden being disqualified from the contest.

This discussion thread popped up this past summer when I was researching the issue of pretreated wood in advising the church on converting their established raised beds. Our local Master Gardener strongly suggested we follow recommended procedure and line the established beds (which were constructed of donated landscape timbers) with 6 Mil black plastic.

Victoria was unaware of that policy, and thought that the youth group was using some sort of thinner plastic in lieu of landscape/weed cloth, which is the main reason the church was given for being disqualified (the other was lack of grids, which the garden had.) Victoria had not seen photos of the garden at the time, and was not aware of current recommended practice, so she offered to consult with Mel on the subject.

Just to be clear, the contest is secondary. I'm primarily concerned with the potential mold issue -- I'll PM boffer and see if he gets an email notification. Thanks for the support, y'all!

P.S. Thanks for adding the Certified SFG Teacher designation to my profile! ~pda

From boffer/Steve, posted with permission:

Hi,

Nice to meet you! Congrats on your efforts to introduce children to the joys and benefits of gardening. If you dig deep into the old threads, you'll find some topics where members shared their experiences doing the same, and offered some clever and interesting ideas to make the most of their activities.

I have a good understanding of, and experience with, mold within a house, but I've never encountered similar mold in the garden. I've lined the sides of boxes with plastic, lined the bottom and sides of boxes with plastic, used plastic as mulch, and haven't had mold issues. I have a few boxes where I heat the soil; no problems there either. It's my personal habit (mainly because I enjoy it) to fluff up my Mel's Mix from top to bottom, and along the sides, when I add compost in preparation for the next planting. If there had been mold issues with MM against the plastic, I would have seen it. Folks have been planting in plastic pots since they were invented. I'm sure we would have heard publicity by now if the use of plastic in gardening created unhealthy mold issues. I'm not a MG, but I agree with the MG with whom you consulted.

It sounds as though you're in a frustrating position at the moment; I know that I would be very disappointed to be eliminated for some unsubstantiated reason. Unfortunately, I have no idea about the Foundation's position on the subject, nor can I offer any suggestions how to expedite a response from them.

Keep up the good work, and I hope you turn those young thumbs green for the rest of their lives!

Steve

> ----- Original Message -----
> From: luckypenne
> Sent: 10/31/12 01:51 PM
> To: boffer
> Subject: Pressure-Treated Wood, Black Plastic Lining & Mold?
>
> Hi Steve,
>
> I posted a question to an old thread on pretreated wood at the SFG forum, but RoOsTeR tells me you're on a break. Here's the discussion link and the question:
> https://squarefoot.forumotion.com/t900-wood-for-sfg#142850
>
> Have you had any problem with your lining and mold? My students (a church youth group) entered their SFG into the Foundation contest this summer and got disqualified purportedly because of the plastic lining. I consulted with the local Extension service per Mel's advice and searched the forum boards here (using this and other threads on pressure-treated wood for reference) before instructing them to proceed with the conversion of their established raised beds, so I feel partly responsible for their success, or seeming lack thereof.
>
> We don't have an Extension Agent on staff ATM, but the Master Gardener who consulted with me said that lining beds with 6 Mil Plastic is the current accepted practice and strongly recommended we do the same, saying there was no need to tear them out and start over as long as this procedure was followed. I've been waiting for weeks now to hear Mel's take on the issue (Victoria was the one who mentioned mold as a potential hazard, but was uncertain about the current recommendations.)
>
> I'd really like to be able to explain Mel's position to the youth group and church leaders who relied on me as the SFG "expert" on the subject. They're still confused as to why they were eliminated from the competition.
>
> Here are some photos of their Hero/Gratitude Garden project: https://squarefoot.forumotion.com/t14034-square-foot-hero-gardens#142486
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~
> boffer, this e-mail was sent to you by luckypenne from "Square Foot Gardening Forum" - https://squarefoot.forumotion.com