Raised bed depth


Will be building my own raised beds soon, not because of drainage issues but due to small garden and I'd like to make them a feature.

How deep is ok?  I am going to build about 18 inches deep ?

Length will be about 20 feet (again back fence and side fence)

width will be about 2 feet (24 inches)

Any advice is welcome!




  • I would vary the depth of your beds, the minimum depth needed for raised beds is 12 inches however some root vegetables for example need 18- 24 inches. Itwould be more pleasing to the eye if the ends of the beds, for example, were much deeper and separate, maybe filled with ericaceous soil, it would also give you the opportunity of growing trailing plants aswell.

  • Thanks for reply, going to go for 18 inches I think then I am in the middle.

    Plan is to grow

    Tomatoes, Onions, garlic, potatoes (growing in pots), french beans, spinach, rocket, might have a crack at carrots, would like to grow brussel sprouts but believe they need alot of room around each plant.

    Thanks again.

  • Sprouts do need space but it is firmness of the soil which is most important and brassicas are susceptible to so many pests they can be more work than they are worth, don't forget to incorporate some flowering edible plants. Your onions and garlic will probably be best left till the spring now as far as planting is concerned as most varieties are either Autumn or spring planting bulbs.Happy planting!

  • I have built 2 raised beds 6 ft by 4ft and 6inch deep not sure how much compost i will need to fill them, thinking of using compost from my local DIY store. Plus should i include some manure, being a novice would appriciate some advice.

  • Big RedBig Red Posts: 1

    In my calculation you will need 12 cubic feet of a mixture of compost, quality topsoil (screened), and garden manure for each of these beds, hope this helps.

  • MikegmMikegm Posts: 2

    I have been using raised beds for a couple of years, using off-cuts from my local timber yard (cheap) This year am using 6' gravel boards, (6" wide planks) Actual dimensions will be 6'x3'  I appreciate some veg may need 'extra' depth but so far the 6" depth seems ok. Obviously the deeper the beds the more they need to be filled!!

  • Thanks for the advise will be a great help.

  • MagicHMagicH Posts: 11

    I have 3 beds each 10ft long and 4ft wide. They are made with old scaffolding planks from a builder. They cost £3 each. The depth is 10" and I used 4ton of topsoil and 12 75 litre bags of multi purpose compost thats 4 bags for each bed! I had fantastic results last year and I hope good results this year. I was told by a very experienced  gardener as long as you do not make them wider than 4ft you can make them any length you like. The width of 4ft is so you can reach the middle of the bed with ease.

  • The longer you make raised beds the further you will have to walk to get to the other side. I agree 4ft wide is the widest to make them.

  • Antonio2Antonio2 Posts: 5

    You can clink the link bellow and it will tell you everything that you need.



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