[simpson-allen]

Needing some advice please. Cleared a massively overgrown allotment plot using a combination of Roundup and a petrol strimmer. Dug over twice trying to remove as many roots as I could but there's still millions in there. As the plot is very clayey and therefore also very boggy I've decided to create raised beds.  

Questions I have are as follows.

Will the weeds and grass roots left in the original soil underneath the planned raised beds, still eventually grow through or will 8” to 9” of soil on top of the old ground be enough to ensure they remain dormant and eventually rot away?

If the answer to the above is yes they will grow back, what should I cover the original plot with before constructing the raised beds. Obviously if I use plastic then the new raised beds could become waterlogged and it presumably also means I am restricted to the size of crops I can grow as the plant roots wont be able to grow any deeper than 8” to 9”where they will meet whatever barrier I put in. Someone suggested cardboard as although it will rot away eventually, it will stay intact long enough to smother any weed roots still active in the old ground.

In any event until it does rot away what crops should I avoid planting because of the temporary restriction on depth.

Any thoughts?

[jack russell]

Hi and welcome

remove as many roots as possible i would not use anything to separate the layers just keep on weeding and you will get there in the end it will be hard at first but rewarding in the end

there isn't a miracle out there that can help or an easy fix IMO.

do it right first time

[eco-friendly]

keep pulling weeds up as you see them they will eventually give up. i dont think covering the whole plot with plastic is a good idea as you said it would become waterlogged.

[Dominic]

In my planting areas, I'm digging down about a foot, completely removing everything bulding raised walls, and then filling with clear soil and new stuff.

If any roots are lower than that, and there have been a few, (I went down almost two feet for one and then gave up, it was still an inch thick, I put on a rock on top and gave up) I'm just hoping they wont be able to grow through a foot and a half of soil without getting any sunlight.

If they do, I'll just lop the heads off till they give up.

[compostqueen]

black plastic sheet mulch is permeable

I'd put double thickness layer of cardboard under the raised beds. You can get this from business parks or your local leccy shop