Posted: 27/10/2013 at 23:28
You will be able to grow lettuce (better in some shade as it doesn't tend to go to seed so quick), kale, brocolli, cauliflower, sprouts, peas, beans, spinach, beets, swiss chard etc.
Why so deep for the raised beds? 2 feet is rather a lot unless you are on a hard surface and not high enough to make a difference if you have knee or back problems. 1 foot deep (300mm) is plenty and so is 6 inches so long as you dig over. Also, it is easier to make the beds 1.2m x 2.4m because of the popular timber pre-cut lengths.
As for what timber to use - marine ply - although rot resistant - won't be strong enough (if the bed half fills with rain at 1m x 3m x .6m it will weigh 9 tonnes with water alone). I would go with scaffold boards if you can get them or decking.