Good suggestions above. Get a book on wall construction, and as laag says, you must dig below the frost line. We put in a cinder block retaining wall last summer because, where it is at, we only see the top part, and never see the 'back' concrete blocks. Didn't want the extra expense of something that looks pretty when I'd never see it. At first, I was going to do it myself, but it was a bigger job than I wanted to do (couldn't get ANY volunteers!), so we contracted it out. Got several bids and the guy did it in two days - a lot less time than I would have needed! He did it right with rebar, etc, and didn't need to fill in the blocks completely with concrete like my top retaining wall (which is much higher and faced with brick). He finished the top with a concrete cap which makes it look nice and 'finished'.

I just built a quartzite patio in Reno, NV. I used the new product, polymeric sand and it worked great! I got the sand in 60 lb bags for $20 a bag from Home Depot. My patio is 9X27.5 and I used 5 bags. It looks like regular sand and sweeps into the joints. You then mist it 3-4 times waiting about 10 minutes between each misting. The water activates a weak polymer glue and locks the sand granules in place. We don't have much problems with frost heaves here, but if a stone moves you can pull up the sand in chunks and step on it or use a shovel to get it back to a granular stage, sweep it back in place and re-mist. Although the polymeric sand sets up pretty hard I don't think it would stand up to a leg from a patio chair, etc., so we plan on getting sled style chairs for the patio. It does do well with walking on it and the sand stays put! So far we are very happy with it. I'll let you know how it goes thru the winter. We get very little rain here but we do get snow.

Are the bricks mortared in place, or merely laid next to each other? If the latter, I would suggest the following: 1) Carefully break down the patio. 2) Lay down cardboard or newspaper to provide a weed block on the bottom of your bed. 3) Reuse the bricks to form the raised bed (6 inches is all that is required now for certain!). This MAY not provide all the bricks you need, but it will certainly give you a good headstart. (You should only need 3 maybe 4 courses of brick. btw, place the bricks double wide, with an alternating pattern...you can mortar them, or just dry stack them. A dry stack will definitely improve drainage, if your ground ever gets oversaturated.) 4) Fill with mix. You will have created a very nice looking raised bed, which should last a lifetime (you may need to rebuild the brick wall after several years or so). In addition, you can grow ANYTHING in that bed, depth will NOT be an issue. The first year, the roots would need to work a little harder to break through the cardboard/newspaper, but the second year, they are gone! If you have a good base soil, there will be trace elements available to your plants that MAY not be in your mix. The plants would then have access to them, regardless of the mix you add. BTW, I recommend fertilizing even if you continue to add compost every year. Continue to have your soil tested, or just add a balanced (organic or not, is up to you) fertilizer, that includes trace minerals like calcium, etc. (Garden's Alive! has some very nice products that are completely organic.) Well, that's what I would do, if I were you! But, its your yard, and your decision. This way would certainly keep costs down, recycle and give your plants access to a much deeper supply of water and nutrients!

Our French Drain is to drain any water which goes through the brick and also to provide an outlet for runoff from the lawn against the patio. It goes the peremeter of the entire patio. There is 6" to 12" of stone to level the patio surface into the lawn grade, but the French Drian is set lower than the deepest gravel and is trenched into the lawn from there. I actually installed 2 daylight discharges - the patio is about 850 sq. ft. I used only gravel within the confines of the patio, then a solid PVC set within gravel into the lawn and covered that trench with landscape fabric. My concern about placing tubing with holes into a dirt trench is the eventual filtration of soil into the tube and clogging. I also have one downspout running under a raised garden and discharging through the retaining wall. Photos of ours are linked from "My Page" and seeing it may give a better understanding of my explanation. Hope this helps - good luck with yours. Very rewarding but also lots of physical effort.