Best material to Build Raised beds

[wildseed57]

Hi all Most of the raised beds that I have at the garden are made from 2x8s and 2x6s and work pretty good they are not treated and are just standard pine boards.
The thing is that I will have to replace some next season and the ones that I don't have to replace any boards I want to raise even higher. I would like to raise them all to about three feet high in the long run, but I need to come up with a better deal than using untreated 2x8s which rot fairly fast, at my duplex my raised beds are made with bricks and work pretty good as they were all free, I got about 400 used bricks, which will go into the garden when I move.
So any Ideas? I don't know of a cheep source of concrete bricks other than where a few get dumped like the red bricks I got.
George W.

[robertb]

This is what I'm hesitating over. We get old scaffolding boards from a contact in a local firm, but all the same I want something that's going to last rather than having to keep rebuilding the things. What's the best wood treatment to use without poisoning the soil too much?

[mjc]

Jan 13, 2011 5:33:43 GMT -5 robertb said:

What's the best wood treatment to use without poisoning the soil too much?

A nice thick coat (or several coats) of a good, old-fashioned milk-lime whitewash.

Here's one that uses powdered casein...

2 ½ pounds casein
7 gallons warm distilled water
25 pounds mason’s hydrated lime
1 ½ pounds borax
Natural earth pigment (optional)

Soak the casein overnight in a large tub filled with 2 gallons of the water.
In a separate tub, combine the lime and 3 gallons of the water; stir to blend.
In a third tub, thoroughly combine the borax in 1 gallon of the water; add this to the lime mixture, then stir into the casein mixture.
Add pigment if desired. Add more water if needed.

(I'm still looking for one that uses skim milk...)

[coppice]

Dec 30, 2010 11:29:22 GMT -5 wildseed57 said:

I want to raise even higher. I would like to raise them all to about three feet high in the long run.

Speaking as a person who uses a mobility aide to get around, I have to ask "why". Why that hight?

[mjc]

Here's a milk one...

A PERMANENT WHITEWASH.

Lime slaked with a solution of salt in water, and then properly thinned with skim milk from which all the cream has been taken, makes a permanent whitewash for outdoor work, and, it is said, renders wood incombustible. It is an excellent wash for preserving wood.

PERMANENT WHITEWASH.

Slake 1/2 bushel of fresh lime with boiling water, covering it to retain the steam. Strain through a fine sieve, add 7 lb. of salt previously dissolved in warm water, 7 lb. ground rice, boiled to a paste, and stirred in boiling hot, 1 lb. of powdered Spanish whiting, 1 lb. of clean glue previously dissolved. Add 5 gallons hot water to the mixture, stir well, then let stand a few days, protected from dust and dirt.

Apply hot.

A quart of this mixture will more than cover a square yard. Colouring matter may be used to produce any desired shade.

Powdered chalk can be substituted for the Spanish whiting. And rice flour is easier to use than starting with whole rice.

The first one posted would probably work very well substituting 2 gallons of skimmed milk for the casein and water to dissolve it (if you can find 'out of date' milk that would be fine).

[sandbar]

I don't think any organic certifying organizations permit it, but what do folks thing about using ACQ-based pressure treated wood? None of the ingredients (primarily copper) are recognized by the EPA as toxic or carcinogenic. Copper is found naturally in our soil and we drink water flowing through copper pipes every day.

Is ACQ pressure treated wood evil?

[mjc]

I wonder if it is a high enough level of copper to repel slugs?

Personally, I'd be leery of that high a level of copper around some veggies...they can be sensitive to it, but overall, I'd say yes, it's probably much better than other types of presure treated lumber. Though, dried, whitewashed black locust will probably outlast ANY pressure treated pine...by decades (which is what I would use...if I were making raised beds).

[robertb]

I hadn't heard of limewashing wood for this sort of job; I suppose it was superceded by creosote and forgotten over here. Some years ago I took out an old gate on my allotment; it had been there for over forty years, and appeared to have been creosoted. The uprights were eaten away badly at the bottom, but still firm. How long does limewashing, which sounds a lot better from an environmental standpoint, last?

[wildseed57]

Yes the white washing does sound viable, over the pressure treated with copper, to keep the boards from rotting to quickly. My Idea of 3 feet in hight for my raised beds would mostly be for lettuce, carrots and other low growing plants while plants that are climbers such as beans, peas and tomatoes would grow well in two foot high raised beds any lower and the roots of the plants would have to survive in a base soil of clay that turns into soup every time it rains as the back yard is lower than the surrounding area which makes it prone to flooding and the soil stays very wet for a long time. I may have to raise the area where the Blue berry bushes are along with raising the soil up around the fruit trees so that their roots are not constantly wet . If I had the money I would have them bring in at least 4 big truck loads of top soil for the back yard and at least that much for the front. Filling the beds are no problem as I can get all the composted cow manure, rotted hay and spoiled cattle feed I want.
George W.