Novice trying to make a small DIY raised bed

curious_squirrel

Hello!

I am quite new to veg growing but before the pandemic I had resolved to make a really good go of it this year. Now of course I don't have access to as many things and also need to do everything on the cheap!

I only have a concrete patio area so all I can really do is grow in containers, but I was wondering if I could make a very small raised bed using an old set of wooden shelves I have spare, to grow things like herbs, and a few radishes and beetroot. It's only about 20cm wide/ deep but that is larger than any of the pots I have the plants in at the moment. I don't want to just end up with hundreds of little pots with individual plants in!

My main question is: since it's on concrete, how would I deal with drainage? I have some bits of slate, broken plant pot, gravel etc, should I put some of that on the bottom? Then would I need to use a membrane before putting the compost on top, and could I use cotton fabric for this?

Any help appreciated, or tell me if it's totally unworkable! Thanks.

JennyJ

Welcome to the forum! I think you should be able to make something that will do for this summer at least.

I take it the back of the shelf unit will make the base of the container?  I doubt it would be completely watertight but drill some holes for drainage as well. You could use stones/broken pot as well but it would take up some of the depth. If it's a big/tall shelf unit perhaps you could cut it in two, take the back off one part and stack to make some of the sections double-height.

Cotton fabric won't keep the wood dry - perhaps line the sides with plastic. Old compost bags are good for this, but whatever you have. Cotton fabric should stop the soil/compost from blocking the drainage though, and I would use it as well as plastic if you can't get membrane. It won't last all that long (cotton is a natural fibre so it'll rot down over time) but should do a season, and in any case if the shelves are MDF or indoor-quality wood they won't last forever either. And because of that, it's probably not worth forking out for membrane even if you can get it.

Sorry if that's a bit rambling - and please post some pics of it if you can! We love a project

Fairygirl

If they're a soft wood, you can paint or varnish them. MDF will warp and twist as soon as it gets wet, so don't use them if that's what they're made of.  The backs of units are often MDF, but the weight of soil and plants will keep it steady for a season.
As @JennyJ says - you need to protect the sides with plastic, and if there's a base it needs protecting too, and plenty of holes, but you could certainly use a bit of fabric to prevent all the compost disappearing out the bottom.
It would help if you could raise it up off the ground too - just a couple of pieces of wood or brick, or anything similar. 

JennyJ

The back might be thin hardboard. If it is, I don't think it would take the weight of the compost/soil so would need to be on the ground. But if it's wood it would be OK raised.

curious_squirrel

Thank you both for your responses, it's heartening to hear that you think it's possible!

The shelves are pretty sturdy, including the back, and varnished so although they won't be completely waterproof I think they will last a while. I rent my flat so don't want to spend too much time and money making anything too permanent. Just want to make do with what I have, and make use of the surplus shelf!

I will line the sides with plastic anyway for extra protection, and raising it off the ground should be no problem. Next step will be borrowing a drill. Hope I can post pictures soon!

Thanks again :-)

JennyJ

Looking forward to the pics now .