Raised bed advice

[Laurasanford111]

Hi all

Getting railway sleepers delivered next week for two raised beds, one for cut flowers and the other for veg, I am a beginner at veg growing apart from tomatoes in greenhouse.

I think the beds are going to be fairly deep, my question is what do I fill them with, top soil, compost etc, all a bit confusing to me. Didn't think about the cost of filling them haha.

They won't be put on grass, there are weed mats down from previous owners so will be putting beds straight onto those and ha having gravel around them etc

Thank you !

I’d remove the weed mats first personally. If they’re the waterproof kind they’ll stop the beds from draining.

Not an expert on what to fill them with, but just a top tip - once they’re filled make sure you cover up any bare soil or it will become a giant litter tray for all your neighbourhood cats - they love fresh bare soil.

I'd remove the weed mats too. They will hinder worms and things getting into your beds (though they will find their way in eventually) and you will want lots of worms.

I'd lay down a layer of cardboard on the bottom (ideally the plain brown kind used for things like packing boxes).

I'd then lay down a layer of well rotted manure - about 5cm+ deep.

On top of that I'd put a top soil to fill them up. By the time anything you plant gets down to the cardboard layer it will have rotted away. In the meantime, it'll just prevent any very determined weeds coming up. The manure will provide this year's nutrients so there is unlikely to be any need to feed futher unless you grow very hungry plants. Next year and beyond, I'd add a top dressing of well rotted manure each year.

And yes, filling the beds is often the most costly bit. It takes so much 'stuff' to fill them up - order in bulk!

Be aware, if you grow veg, that it is not always wise to grow the same category of veg in the same spot year after year (e.g. root or brassica). This is because that veg will take the same nutrients out year after year - these can be replaced obviously. But also because it encourages pests specific to that veg to really get a hold. It may be that you would benefit from rotating what you grow a bit.

The cheapest way is to bulk order topsoil. You want a topsoil/compost mix although in my experience there never seems to be much compost, so make sure you add some yourself. As time goes by you will gradually improve the soil by adding your own compost and other organic matter.

Agree with PPs, ditch the weed membrane and put down cardboard.

Look at YouTube channels for advice. Charles Dowding is brilliant on soil, and I recommend Huw Richards too for loads of useful tips.

Have fun!

PPs have good tips. I agree about taking up the weed mats. I would put down quite a thick layer of old cardboard boxes or newspaper or both. Then a thick layer of manure - whatever is cheapest. Then all your leaves, garden clippings, vegetable peelings and so on. Depending on the depth that needs to be filled, I might not buy topsoil but would throw in any leftover from digging in other areas of the garden. Then proper compost. Then a thick layer of mulch such as pea straw.

The level of the bed will go down as the organic material breaks down, so next spring when it’s time to replant, you clear out any persistent weeds, and repeat all the layers and so on for the following springs.

I only started trying no dig veg beds a couple of years ago and I’m very happy with how it is working.

As PP have mentioned, check the weed mats are water permeable (you can just pour a bit of water on them and make sure it goes through) as if they're not, you're going to have a big issue with drainage. If they're not water permeable, I'd cut out the sections where the beds will be and put down a cardboard layer for weed suppression instead. If they are good to go, depending on depth of the beds, you can fill some space with twigs/old raked leaves etc to add to organic matter as they break down, and then for soil do a mix of compost (we do mushroom compost) and garden or top soil (just be careful of the quality of top soil - it can be pretty filled with rocks and other stuff you don't want if you're not careful.)

What I would add (not sure if anyone else has already sorry) is that railway ties/sleepers are known to be coated in a bunch of chemicals and as such are not at all recommended for using for food producing beds, because they will contaminate your soil and ultimately your food. Could you use both beds for flower beds and do another food safe option for the veggie bed? Sorry.

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