Welcome to the complete guide to raised beds in greenhouses, if you have a question about raised beds in greenhouses, then you are likely to find the answer below!
Can you put raised beds in a greenhouse?
Yes, and if you ask me you should. Raised beds give you much more natural soil and come with many benefits over grow bags or pots.
To start with they will hold moisture a lot better meaning you don't need to water in the greenhouse as often.
And if you do forget to water your plants won't be in as much trouble as they would if they were in a pot or grow bag.
Secondly using raised beds all the way around the perimeter of your greenhouse really allows you to maximise the precious indoor growing space.
You will find you have much more room for plants if you use raised beds over pots and grow bags/
You will also be able to nurture much better soil when using raised beds. You can continually improve the soil and keep adding compost to it to make sure it is at its best every year.
This is harder to do with pots and with grow bags you are expected to throw them out and start fresh every year!
Raised beds also help the soil to heat up quicker than pots or grow bags would, couple this with the greenhouse effect and you will be able to extend your growing time at both ends of the usual season.
How deep should raised beds be in a greenhouse?
As you can see in the photo above I have made my raised beds three gravel boards deep in my greenhouse. These boards are 150mm deep each, so a total depth of 450mm.
I like this depth as it allows me to get plenty of soil into the greenhouse which should help with water retention and give the roots of the plants I put in there plenty of room to grow into.
It also means that when winter comes around, I have the option of growing root vegetables like potatoes and carrots straight into the raised beds in my greenhouse.
How do you build raised beds in a greenhouse?
I used gravel boards for my greenhouse raised beds. These are made from treated wood so they wont rot too fast and are readily available from DIY stores like B&Q.
I then used a post in each of the bed's four corners and screwed the gravel boards to create the bed. This is a really simple way of building a raised bed and it worked really well for me.
The greenhouse I am building in was constructed by yours truly out of timber.
Because of this, I had the ability also to fasten the gravel boards into the actual greenhouse structure. This helped make the whole structure more rigid but isn't really needed for building raised beds.
How do you layout raised beds in a greenhouse?
When laying out raised beds in a greenhouse, it is essential to think about light.
You want as much of your growing space to be facing south as possible to maximise on direct sunlight.
You also don't want to plant tall plants like cordon tomatoes or cucumbers on the south side of your greenhouse as they will block the light out from everything else.
Try and grow in a terraced style with the smaller plants on the south side of your beds and the taller ones on the northern side.
If you need help with filling your raised beds, then have a look at my what soil to put in raised beds article.
Helen Wood says
Thanks for your advice.
Tad says
Hi Daniel
I am about to build some raised beds in my greenhouse which has a solid concrete floor, I
am concerned about drainage once the soil at the bottom of the bed is in contact with the floor. Do I need to put on layer of shingle or anything else ?
Daniel says
I have mine on a concrete bed and drainage isn't an issue, but there is cracks and gaps in my concrete. Maybe drill a few holes into the concrete so excess water has somewhere to drain?