Raised beds...on a brick patio? Is this a good idea?

[K8-EEE]

My friend ordered the same square foot raised bed as mine, I told her I would help set it up.

But now she tells me the only part of her yard that has sun is a brick patio!

The thing is....the bricks are laid in sand, not cemented in, so wouldn't it be better to pull them up? Under the bricks is mostly tree roots but I figure drainage wise, even if we loosen it up just a couple of inches where the roots aren't, it's way better than setting the thing up on bricks, right?

Also we live in a really hot dry climate so I think whatever hassle it is to take the bricks out now would be a fraction of the hassle of having your stuff dry out 2 hours after you water it all summer! Maybe the 12"side would be OK but half of it is only 6"! Six inches of soil on bricks in the valley sun? That's not good, right?

Although I've seen rooftop gardens so....there must be a way but I'm guessing those are deeper than 6"!

oops, edited for careless glaring spelling error in title!

[Kolesar]

1. I think you have this figured out

One wants a garden to be on soil so that the roots can reach a little deeper and so that water from the deeper soil will "wick" up to the surface soil through capillary action. If the patio was laid on a deep bed of compacted and crushed gravel (and layers of sand near the surface), then your friend is not going to get those capillary effects. I would recommend digging out those rock and sand layers and adding better soil from somewhere else. From the sounds of it, your friend has a simpler installation without all the rock layers. I would recommend deep-forking or spading up the lower layers so that her garden gets the capillary effects.

You could put sun shades over the plants so that they don't get super-blasted by the hot midday sun. Spun row cover cloth can be obtained that admits 70% or 85% of the sunlight. Your plants will still have enough sun. The sunshade could be set to the southwest so that it admits direct morning sun, but shades the garden during the hot part of the day. All of those bricks are going to store the midday heat and make that a hot place as they reradiate infrared heat.

If you have seen roof top gardens, then that would be container gardening. I would imagine that one would set up drip irrigation or a soaker hose laid across all of the containers and give the plants frequent watering. People put timers on their outdoor faucets for such an application. happy gardening!

[K8-EEE]

2. Thanks!

Well she has as of this morning been talked into it, LOL. I've never done any gardening except in my own yard and people visiting me assume I'm an expert gardener but really I'm only an expert in my own yard!! I'm nervous doing somebody else's - already issues are coming up that I've never had to deal with.

[Arkansas Granny]

3. Have you ever heard of straw bale gardening? You can apparently

grow a variety of plants in straw bales, even on concrete driveways. I'm going to give it a try this year with tomatoes and see how it works. It sound really interesting.

http://www.no-dig-vegetablegarden.com/straw-bale-gardening.html

[LiberalEsto]

4. Wow, that sounds interesting

I've tried lasagna gardening, which worked beautifully. The past few years I've been doing the square foot method, which is amazing.

We were talking about extending the planting areas beyond the existing square foot bed in order to plant melons and squash. But my back is getting worse, and I just can't deal with bags of peat moss and compost any more. If my daughter and her boyfriend get the bales and set them in place, this sounds do-able.

Thanks!

[Arkansas Granny]

5. There are apparently some limitations on what you can plant, but I'm

going to try tomatoes and peppers in the straw bales and maybe an eggplant. I'm going to be doing more container gardening this year, although I will probably put a few things in my raised bed, too. I just want to cut down on as much weeding and bending as possible.

[K8-EEE]

6. Wow! Super interesting.

I'm really curious to see how that works out, hope people post pix of their straw bales!

[Ernesto]

7. Not a problem....

I have 12 1' deep grow boxes all on concrete slabs. The boxes average 30 square feet each. I put them on concrete to keep tree roots from invading and have had a huge success.