Planting on top of concrete ?

I am considering creating some raised beds or Hugel-beds on top of some concrete.
I want to begin my Urban permaculture on some leased property. Since I don't own it, I can't tear up the area; only build on top of it. I'm not sure how well beds would work on top of the concrete.
I need some help/suggestions/criticism.

Of course trees would be out of the question but shrubs and bushes might do okay.
Drainage issues?
Please help. What do you think?

I just made the strawbox of potatoes that is recommended by Bill Mollison in his permaculture techniques pamphlet. It is listed somewhere within the first four pages of the pamphlet and he says that it can also be built on concrete.

I used a regular store-bought straw rather than organic herbicide free straw -- I may regret that. But otherwise I think it is a pretty cool project. Here in the hot sunny south I would recommend places this box where it gets morning sun, maybe a little at noon, but afternoon shade - especially on concrete.

Here is a link to the post, picture of the straw box and the pamphlets strawbox of potatoes

Here in the hot sunny south I would recommend
...morning sun, maybe a little at noon, but afternoon shade...

That is sound advice, particularly with the thrown in humidity.

The morning exposure to the sun dries off the night's dew. Prevents many mold, mildew, fungus problems.

We have had demo strawbale gardens growing on concrete and asphalt...It is an easy way to grow..On the concrete we have found the heat creates the need for a bit more watering.You could also look at doing some square foot gardens which do great on concrete as well..

I watched a youtube episode of growingyourgreens that had a community garden that was in your exact predicament. One good thing about concrete...you don't have to worry about weeds growing up from the ground! I don't think drainage would be much of an issue unless you seal the bottom of the raised bed for some reason(and I can't really think of a reason to do that).

http://www.youtube.com/watch?v=PtcmR4ltv6Y&feature=results_video&playnext=1&list=PL1280D4A4EBB48C52

We're sort of planting on top of concrete all the time. We live on a mountain where most of the soil depth is measured in a few inches down to the bedrock or ledge. I've made a great deal of compost to deepen this in the gardens. It works but not very deep rooted.

Cheers,

-Walter Jeffries
Sugar Mountain Farm
Pastured Pigs, Sheep & Kids
in the mountains of Vermont
Read about our on-farm butcher shop project:
http://SugarMtnFarm.com/butchershop

Many people plant dwarf trees in pots ..so they could go on concrete..pretty much anything can be grown in a container, except maybe the largest trees...if the container is large enough.

So, somethin' to be aware of is constant water on cement can damage the cement. Learned that in an irrigation class. Don't know how long it takes to damage. Maybe put some tarps or somethin' down to keep the cement protected or have the plants and soil lifted off the ground.

Good luck!

the slab is a huge heat sink. The absorbed and reflective heat will be tough on your plants - but it should be doable with care.