I'm starting to think about fall vegies - can you grow beets and carrots in 511, or will the texture of the mix deform the shape of the vegie?
Should grow just fine.
The 5-1-1 is much looser than the typical garden soil, so I can't imagine any deformation
occuring. I think you'll want to use deep pots.
I recently started reading ROOT DEVELOPMENT OF VEGETABLE CROPS by WEAVER and BRUNER 1927. The hand-drawn charts showing root depth and spread for certain ground-planted vegetables are as beautiful as they are informative.
I am also reading other more modern web based resources about vegetable root depths and container gardening and looking at my results here in year one of container gardening on raised tables.
Disclaimer: I am only recently experimenting with 5-1-1 so I have little to report on that factor other than the fact that I did use 5-1-1 to rescue a tomato plant that had the misfortune of being transplanted to a "Georgia clay bowl" with almost no drainage. My purpose of joining this post is to discuss the limiting factor of container depth on vegetables. Better soil, drainage, fertilizer, watering practices, light etc. will all help plant health -- I love the picture and discussion about limiting factors here: http://forums2.gardenweb.com/forums/load/contain/msg0921071615772.html -- but if the container depth is too shallow for the particluar plant it will suffer and the other factors will only be able to help so much.
So back to depth and veggies... lettuce and herbs like basil seem to do OK at 8 - 12". I have several 3' x 2' x 9" containers and my lettuce did well and basil did very well. My watermelon flopped. Canteloupe / Muskmelon... I got maybe three tiny but tasty melons. Cherry tomatoes did OK but I expected more. Beefstake tomatoes... yields have been poor but I'm getting some. Eggplant... doing better now that I've thinned them and moved some to other deeper containers but still no fruit; flowers are dropping; I have changed fertilizer and they are looking much better, we'll see how it goes.
My carrots and beets which the original poster inquired about have not done well at all in their 3' x 2' x 9" containers. According to WEAVER and BRUNER mature beets can go as deep as 11 feet at the tap root and 2 - 4 feet around the beet will root and then go down up to to 6 feet. Well, so much for my 3' x 2' x 9" container producing a good beet yield; indeed they look puny today and I planted them 3 months ago. Too many in one container, too - I forgot that each "seed" is really a cluster of seeds and I should have thinned. In any case my 9" deep container probably has little chance of success.
In my 18" containers I am having success with Yukon Gold potatoes, slice cucumbers, and Ace VF 55 tomatoes although the tomatoes I transplated to the ground for comparison's sake are doing even better. I have to bend over to tend to them which defeats my purpose of building a raised container garden but I wanted to compare the results.
For my fall crops I am going with more 18" containers and even deeper if I can find them but I do need to remember that I will have to put dirt into them and take dirt out of them. My whole set up is geared towards minimizing the need to bend my back. I may well build some deeper containers with doors for thrashing soil; should be great for potatoes, e.g.
My 9" containers will be for lettuce and herbs next year and I'm not sure what else just yet.
Here is a link that might be useful: Beet root diagrams and discussion from 1927 book
FWIW, I had a left over pot and some 511, and grew some radishes. It worked fine. I'm tempted to try carrots. They'd probably be huge since roots move so easily through 511.