rasied bed question

[ninny]

I wasn't sure where to put this at.

Im thinking of making rasied beds for next year. The best place i have to put them is on cement though. Would that be okay? I would be making them with bricks. How high should i make them and how big?

Thanks!

 

[patandchickens]

There will be two main factors you're contending with.

One is heat... an 'island' bed surrounded by concrete will be hotter, especially at root level, than one surrounded by lawn or soil. Provided you water them enough, heat-lovers like peppers and eggplant might *appreciate* that situation; but expect poor performance from things that prefer their roots cool (e.g. peas) or their whole selves cool (e.g. lettuce or spinach).

The other factor is that unless you have a whole big lot o' bricks and can make your wall quite *thick*, you'll need some wood or something like that, forming a SOLID wall to the raised beds. Although of course you could put bricks outside of it for looks if you want. If you try to make a normal, thin, nonmortared, just-stacked-bricks retaining wall for a raised bed more than 4-6" high or so, the pressure of the soil wanting to slump outwards will just push it apart over time (and rather messily). Because of the heat issues involved I would suggest making the bed deeper rather than shallower; 12" would be about the minimum I'd try, personally, on a slab.

Good luck, have fun,

Pat

 

[ninny]

Thanks pat! I have tons of bricks just laying around so i figure i'll just put them to use. I was reading where someone put hay on the bottom then soil. Why would you do this and could i use straw instead?

 

[vfem]

Thanks pat! I have tons of bricks just laying around so i figure i'll just put them to use. I was reading where someone put hay on the bottom then soil. Why would you do this and could i use straw instead?

I am concerned about how deep you are going with concrete being the base of your raised bed? Many plants send their roots very deep and they won't be able to get what they need going through concrete? Things with shallow systems won't mine, like lettuce and such... but what about tomatoes?

For more info on straw or hay as a base for any gardening search for hay bale gardens and you'll see how they work those options. Might be worth looking into.