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Soil/compost mix for raised vegetable beds?

Last post 08-12-2007 12:25 PM by bogweevil. 3 replies.

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  • 06/12/2007 05:48 PM
    • Harris
    • 06 Dec 2007
    • 1
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    Having recently moved to a new house in on the Hants/Surrey border I wish to cultivate a vegetable patch. The garden has very sandy soil and many trees with shallow roots, criss crossing the garden. I think that a series of raised beds of approximately 45cm depth would be a suitable option and have an area of the garden with good light, in mind. I would like to prepare the beds over the Winter for sowing in early Spring. My query is what mix to fill the beds with. I have no soil as such in the garden or compost heap to plunder. Look froward to hearing your thoughts.

  • 07/12/2007 01:30 PM
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    Hi Harris, Welcome to the board! :-) I'm studying soils on my RHS Level 2 at the moment, and one thing I've gathered about sandy soils is that whilst it gives good drainage, and generally warms up quicker than a heavy soil, it can lose moisture and nutrients very quickly. It sounds like you're asking the question at the right time (i.e. before you get started). You've not mentioned what PH value the soil is, or how big an area you're talking about? Whilst I can't give you expert advice, I'd be tempted to get a good thick layer of organic material on it now; leaf mulch or good garden/kitchen compost would probably be a good bet. Are you planning on then buying a bulk load of top soil to raise it up to 45cm? 45cm does sound very high; would 30cm be good enough I wonder? I know you can add powdered clay to extremely sandy soils, but I don't have any personal experience of that, maybe somebody else on here does? I'm not sure as to the timing, but there are also green manures available quite cheaply nowadays, such as winter rye, that can also be planted to help fix nitrogens in the soil, etc. With such a mild winter at the moment, it's not too late to sow these crops (I did just 10 days ago - and I'm in the cold northern area of Yorkshire, and they've already come on a treat). Anyway, that's just my layman's thoughts; I'd also be interested to hear other people's opinions who are more experienced than myself. Cheers for now, Paul.

  • 07/12/2007 03:27 PM
    • kandeakay
    • west sussex
    • 03 Aug 2007
    • 137
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    Hi Harris - we made raised veg beds three years ago - about two foot six tall - which keeps the rabbits out as well as being easy to work! They were on part of the lawn, so I simply turned the turf over and put grit on top of that - we are on clay here - then added Rolawn topsoil, delivered in bulk bags, and added whatever was appropriate to the bed - depending on what was going in it. Mushroom compost made a good addition. I added a little blood fish and bone for good measure. We have 4 beds. They do need topping up as the levels sink - I use my own compost to raise it. One mistake stands out and that was putting molehill soil from the adjacent field onto them - so allowing slugseggs in - having previously been slug free - hey ho they would have probably come in with my compost anyway! Forgot to say we (I should say my wonderful husband!) used planks to build them and they are lined with heavy duty polythene type material up the insides so the veg don't come into contact with the wood. Hope that helps.

  • 08/12/2007 12:25 PM
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    It is usual to scoop up soil from the paths around your raised beds to fill the beds adding compost or manure at up to 10 percent by volume. I have built many raised beds by this method, although I find 15cm high sufficient for my beds. Where soil is sandy raising beds 45cm high tends to make them rather drought prone in my experience as drainage and water loss is too sharp for dry southern areas. In western districts the extra dranage and water loss would be ideal of course, Thus you raise the bed by addition and subtraction if you see what I mean, saving buying in soil. I find in my own garden that it is often convenient to build a raised bed in order to use up top soil made surplus to requirements by shed building, pond sinking, patio extending and path laying. The paths between the beds can be made weather proof and easy to walk on with gravel, bark, slabs or whatever pleases you. The organic matter won't be enough to feed your crops so you will need fertiliser. As your investment in time and materials will be high you might consider a soil nutrient analysis to be sure you get the best out of new beds - the RHS offers a service where the results are interpreted for you. Boggy

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