Soil mix for raised bed?

(Question)

Hi there – I live in Vaughan, am new to raised beds, have read around and am looking for advice on the soil mix for a raised bed to grow vegetables.

Bed dimensions: two legs of an “L”, 16″ high, 22″ deep and multiple sections about 8 feet long. The bed is being built against the fence by the way, and I will be reinforcing the fence for this.

My ground is a bit uneven so the first layer will be a few rocks, then gravel covered by weed fabric.

Moving up, I am looking at providing a couple of inches of wood chips and grass clipping, covered with untreated cardboard.

What do I use as my top/ planting layer. I was thinking of getting triple mix in bulk and mixing in some compost or manure. Is there a better medium?

Thanks

(Answer)

Raised beds are a great addition to a garden – not only are they easier on the back and knees they also protect your soil from compaction and erosion. It sounds like you are well on your way to making a fantastic raised bed.

What you are adding all sounds great. The only layer I would leave out is the layer of wood chips and grass clippings because as they break down they are likely to tie up nutrients (nitrogen namely) that your plants will need. Triple mix with compost sounds fantastic. If you want, broken down wood chip mulch would be valuable on top of the soil in between and around your plants – this will retain moisture and add nutrients but won’t tie up necessary nitrogen.

For further reading see some of these great links with some other possible soil mixes:

https://eartheasy.com/blog/2014/04/3-useful-soil-mixes-for-planters-and-raised-beds/

https://www.gardeninginraisedbeds.com/raised-bed-soil-mix/the-perfect-soil-mixture-for-filling-your-raised-bed/

https://growingrealfood.com/how-to-make-garden-soil-for-raised-beds/