First question is are your planning raised beds for your garden? I would suggest it especially because of the quality of your soil. This way you have some form of control. You are correct to use triple mix to improve your soil and you do need about 6 inches to creat a good enough depth for vegetable plants. I'd be inclined to dig it in the sand which will improve it's water retention properties. You might discover that a truckload would not be sufficient if you plan to cover an entire backyard area. However in a raised bed, you will have more than enough soil and what's more it may not be necessary to dig the soil into the sand. Eventually you will get such creatures like worms that will do the job for you.

I also like to ammend the soil further with compost and composted manure. How do you know if your soil is okay? It resembles a crumbly chocolate cake. You can squeeze it together and it comes apart in crumbs. It must have good organic content and it should have good water retention properties. Balance is always key.

Love those veggies!
I agree with Ianna, raised beds are the way to go. The deeper/higher, the better. Just make "boxes" with the widest boards available, these tall enclosures will hold a lot of "good soil" which you are going to purchase. Make it ease.....I suggest just to dump your top quality garden soil/mix into the "boxes" so that they are topped right up tko the very top (this will settle a bit over your first season, and you may be able to add more on your second year.

...some people use patio stones propped up on their sides. see Lee valley for this method (link below).

I don't suggest buying the kits too much $$$$

Scroll down to the bottom of this site and do a search for raised bed gardening....you'll get all kinds of ideas.

Have fun and good luck!

Here is a link that might be useful: leevalley patio stone raised bed

Another option, (not too pretty looking, but if you have the space, could work,) is bale gardening. Basically you plant veggies in the top of straw bales. After a season, the bales can be broken up and will compost to make a great base for next year's garden. I read about it on G'web somewhere, but I googled it and found a link.

Here is a link that might be useful: bale gardening

Neat link, Wendy. Thanks for sharing.

I'm going to try the 'bale' method this year (just have to find a source of hay bales). I'll be doing it, believe it or not, in my front yard, because it gets the most sun, and frankly, I don't like looking at veggie beds from my back deck. I much prefer flowers. I love fresh toms though, so we'll see what kind of a 'court' I live in this summer, and how many tomatoes, zukes and cukes I'll harvest before the neighbours get them!
Will post as to success with this method.

Just a note, make sure the bale does not contain seeds otherwise you'd be having fun picking out the weeds.

Because of my lack of space and because the only area I can set my garden is routinely flooded by my neighbor's downspout, I have to resort to the bagged vegetable garden method. This method utilizes bagged earth with an large squared opening were one can grow vegetables. I can then mulch the bag with straw (sans the seeds) to make them look decent and to reserve moisture.

ianna

Thank you all for the great advice. I had considered raised beds, but decided against them. You have convinced me to revisit the idea and now I'm all for it! I am planning on making the beds 4' wide out of 2"x8" lumber. I know 2" may seem a little heavy, but i figured it would be more versatile. I'd like to have the option of adding additional frames with glass or plastic (to convert to a cold frame), or chicken wire or row cover to keep out critters and pests. Also, I am planning to build a chicken tractor for two barred rock hens. So.... I figured if I make my tractor 4' wide I can roll it right up on top of the raised beds (since I have heavy 2" lumber sides to support it) and benefit from the chickens "working the soil".

excellent choice... I would suggest that you do some further research by getting yourself a good book because simply setting up the bed would not be enough.. There are many aspects concerning soil,fertilizing, plant rotation, disease, insects, pests, plants that do well together (and plant that dont), irrigation, plant covers (for frosty nights and for insect protection), etc.. For instance my problem has to do with rabbits and raccoons.. Some may have to contend with mice, birds and deer. You could create a removable frame with chicken wire to protect your plants from birds and other such pests.

Also try to learn how to grow your vegetables from seeds inhouse because many may require sowing before the last frost date.

Also another good site to check out is Mother Earth News. Your idea for rock chicken is something else. (by the way, avoid using fresh chicken poop as fertilizers because they are far too hot, if not too concentrated... In fact, don't ever add any fresh manure to a garden bed, it has to be completely composted first) Wish you much luck on your endeavours.

I just read this article this week on the Mother Earth New website about building a chicken run around the garden to keep out the bugs & the weeds. Because it's only 3 or 4 feet wide, the author said that hawks are reluctant to land because the fences are too close together. He also built a culvert under any gates so the chickens could go all the way around.

Here is a link that might be useful: The Chicken Moat

Mother Earth News is a 'motherload' of information. I just love that site.