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What soil to put in raised beds?

If you have just finished building a raised bed, maybe even using my guide, then your next thought will be what soil do I put in my raised bed? Well, let me help you out and also offer a few money saving tips!

what soil to put in raised beds
what soil to put in raised beds

When it comes to filling a new raised bed you have lots of options. You could just go out and buys lots of bags of compost and fill the raised bed straight up with compost.

This would create a good growing environment for your plants but it would be very expensive and pretty pointless as the compost right at the bottom of your raised bed won’t really be used, depending on the size of the bed obviously.

Fill the bottom with weeds, soil, sticks
Fill the bottom with weeds, soil, sticks

Saving money on filling a raised bed

The bottom of a raised bed is not particularly important, at least not at the beginning of a raised bed’s life. That means that filling the whole thing with compost is just throwing money away, and you miss out on some nice benefits that come with putting other stuff in.

So what is this other stuff? Well, I like to start the bottom of raised beds with really bulky waste. So stuff like sticks and logs, really big bulky stuff that will take up a lot of space, reducing the amount of compost you need to put in your bed.

All of this will rot down over the years and provide good nutrition to your soil for years to come. On top of the logs, I like to add grass cuttings and weeds, the kind of stuff you would add to the compost heap.

Just be careful with what you are introducing here, don’t go adding horsetail roots for example or you might find yourself fighting them off for years to come. The same could be said of dandelion roots but on a smaller scale.

Adding Garden Soil

This is where some added benefits can come in. I like to add plenty of ordinary soil from the garden/allotment into my raised beds. You can see the big square of lawn turned upside down in the middle of the bed above for an example of this.

The benefits you get from this are obviously filling your raised bed up for free but more importantly, it is all the natural life you are adding to your raised bed.

There will undoubtedly be lots of worms in that soil I just dug up, now living in my raised bed. These will work away improving the soil for me from now on.

Beyond just the creatures you can see there will also be lots of smaller creatures like nematodes that feed on slugs along with all the good bacteria that make up a healthy soil.

If you just add pure compost you are missing out on all this, and if the bottom of your raised bed is sealed then how are things like worms ever going to find their way in? Add onto this the fact that some store-bought composts are actually sterilised and you then have a really strange soil in your raised beds, devoid of the usual life that helps plants to thrive.

Compost top layer

Once the raised bed is getting near to the top I add plenty of compost to give the plants that will be growing in the bed plenty of nutrition. You can use compost from your heap if you are lucky enough or if not store bought compost will do just fine. Use regular multi-purpose compost, peat free if you want to be more environmentally friendly.

Compost top layer in my raised beds
Compost top layer in my raised beds

So there we have it, a fully filled raised bed at a fraction of the cost of filling it completely with compost and the rest bed is healthier for it. A real win-win in my eyes.