Question about portable garden bed 2

Hi. So I'm a beginning gardener. Theres a great website with lots of social activism videos,articles and presentations called Films for action.com which I found out about permaculture. I decided to join this board since part of this community is sharing information right?
So to to the point. I do have soil in my backyard although in this urban setting there is a refinery down the street. I'm nor sure what element that plays in the health of the soil but none the less my grandmother is planting her own things in the garden and weeds it herself. So I decided without putting my stuff in her space I decided to make a project out of it and by this week hopefully I will be building a portable raised garden bed. I think doing it this way may help me learn more how I could contribute what I learned back to the other areas of Los Angeles sprawl plus we have concrete in the backyard so it works out. I figured It would look something similar to this picture below but with the dimensions of about something 8x4.



My questions are now

1.What type of wood is safe to use for the garden and growing of vegetables and should it be painted?

2. As far as soil would it be best if I bought some first to experiment with growing while trying to restore the original soil in the back yard if its needed?

Hi Kelso, any wood will do, except pressure treated wood which can leach toxins into the soil. Painting or staining the outside is fine. Oil based paint or stain is durable and will work fine. So will latex paint or stain. The planter design you have described will work very well in your situation. One thing you can also do in conjunction with your planter is some kind of composter to help augment your soil periodically. Very cool and permie. Your 4x8 dimensions will be heavy, so use the largest casters or wheels you can, as this will make your planter easier to move. Keep it simple. Good luck from Houston, Alaska- Tom and Vania

I went to Lowes today and found that all the wood was treated in some way. All the wood had ACQ which after reading was a replacement to the arsenic treated wood of older years.

Is my only bet going to a lumber yard and getting expensive cedar? I wanted to do this portable bed so it would last a while and I could try to grow the plants together rather than in many many bins.

btw it was just an 8x4 sheet I was looking for not the dimensions of the box I was going to make. That would have been something to the effect of 63x33x24.

Any MORE info on non treated wood would be great.

Hi Kelso, you shouldn't need to get cedar. At our Lowes, the regular 2x6, 2x8, etc. is not treated. This is what I use, and have had no problems. However, exterior plywood with 2x4 and 4x4 dimensional framing will work well too. 5/8 or 3/4 inch is the ticket here. Keep the "nice" side to the outside for finishing. If you put a barrier between the wood and the soil (recommended) such as plastic, you'll have it made. This type of approach is standard practice up here and is effective. There are other ways of doing what you want as well that do not include wood touching soil such as permatuffa, ferro-cement, and cement permeated canvas. All are strong, attractive, and easy to build. For those who object to standard iron-based concrete, magnesium based cements are the ticket.Magnesium-based cement has about 70-90% less embodied energy than standard iron-based cement. This structure can be lighter than wood, and inert to normal chemical attacks such as acid, and high alkaline situations. If you would like more info on these alternative construction techniques, let me know.
Regards from Houston, Alaska
-Tom and Vania

Kelso Kira wrote:  That would have been something to the effect of 63x33x24.

Even with a raised bed to those dimensions you're going to have to have at least 5 more people to make that MOVE at all, maybe even more.

IF you're thinking you'll roll it around the lawn - forget that. It would be harder than having that bunch of guys pick it up and move it.

To give you an idea of the weight, take a 5 gallon bucket into the back yard. Fill it with soil and tamp it down a bit to fill all the voids. Now, carry it around the periphery of your lawn a couple of times. OR, you can do some calculations by finding what a Cubic Yard of lawn material weighs and calculate the Cubic Feet or Yards of the raised bed.