Clearing an overgrown allotment

The New Plot
So, you have been on the allotment waiting list for a few years, then finally the day arrives that you receive the offer of a plot. With great excitement you go to inspect it, expecting an orderly garden you can start work on straight away. However, when you get there you find that the expected well-ordered plot to be an overgrown jungle of weeds.

Unfortunately this is only to be expected. The reason that an allotment becomes available is mostly because the previous occupant gave up on it and let it run wild for a year or two. I did overhear one new allotmenteer complaining,”Surely the council could have tidied it up a bit for us first” ! Unfortunately that's not the way it works.

Welcome to your new allotment!

This was the situation Mrs Spud and I found ourselves in 5 years ago. Although we were a fair way down the waiting list, everyone else who had been offered that particular plot had rejected it because it was so overgrown.  There were brambles encroaching from the boundary, and a chest high forest of nettles and other weeds throughout.

So firstly we spent a couple of weekends cutting back the brambles, pulling up the top growth by hand and putting it all in a pile ready for burning. Then we marked out our first bed.

How not to do it

Both Mrs Spud and I have bad backs, but our new neighbours assured us there was no alternative to simply digging the plot over bit by bit. So I dug. First I would turn a spadeful. Then bend down and pull out all the weed roots and debris and put to one side. And then the next spadeful. And so on. It was backbreaking work, and as my back was already broken, I could only work like this for very short periods of time.  Progress was so slow it was almost non-existent.

After a while we developed a 2-man technique to avoid constantly bending up and down. I would stand upright and turn the soil with the spade, while she, on hands and knees, removed all the weed roots she could find. It was a lot easier, as neither of us had to keep bending up and down. Nevertheless it still hurt and progress was still slow. Over 2 months we managed to clear just 2 beds, a small fraction of the allotment.

How to do it.

Remembering something I had read about the use of mulches to suppress weeds in one of Bob Flowerdew’s books, I decided to try a different approach for the early potato bed. I bought some weed suppressing mulch - the kind of black woven material that is often used around shrubs and covered with bark chippings in borders. I rolled it out where I wanted a new bed and pegged it down. Then I cut star-shaped slits in the fabric and used a bulb planter to removed a core of soil. Into the hole I threw a potato, and then replaced the soil and folded the fabric back over the top.

When the potatoes started growing, the shoots pushed through the hole (together with one or two adventurous weeds, which I just pulled out.)  Potatoes are heavy feeders, but there was ample food from the rotting weeds and their roots beneath the mulch. There was no need to remove the mulch to water, because it is porous and the rainwater was able to seep through. 

When it was time to harvest the potatoes,  I simply pulled out the haulms and rolled back the mulch.  A few of the potatoes were laying on top of the soil, but because they were under the mulch they had been kept in the dark and had not gone green.

After harvest, the mulch was removed and the bed forked over.  In four months many of the weeds had died and rotted but some had survived. However, since the soil had already been loosened while removing the spuds, it was easy enough to fork them out.

I used this technique on two other beds that first year, one for maincrop potatoes, and one for courgettes, squashes and cucumbers. In both cases it worked very successfully. In fact, as the mulch did not need to come off these beds until the autumn, it was even more successful in killing the weeds than on the new potato bed.

I see no reason why the technique shouldn’t work too with things like sweetcorn, and also the brassicas, eg cabbages, brussel sprouts and cauliflower.  In fact anything you can start off and grow to a decent size in pots, and plant through a hole in the mulch.

It might be possible to use the same technique using free old carpet instead of bought mulch. I don’t know, I haven’t tried.

Carpet Mulches

We only cultivated a small part of the allotment that first year. The remainder we covered with old carpet scavenged through Freecycle (or Freeagle as it now calls it self) and ignored until the following season.  After 12 months, when the carpet was removed, the soil was completely clean apart from a few weakened and blanched dock plants, which just pulled out easily.  The other weeds and their roots had rotted, the worms had dug them in for us, and the soil was ready and waiting for planting. We did fork it over first, but I’m not sure it was necessary. 

Of course using this technique you have to wait for a year before growing other plants, like onions and carrots, for which you need the soil to be already prepared. But patience is what growing vegetables is all about.

Rotavating
Rotavating a garden can save labour on digging, but you should only consider this option once all of the perennial weeds have been removed.  If used as a quick fix on overgrown ground, all that happens is that each perennial weed root is chopped into ten pieces and the weed problem is ten times worse.

At some point, on our allotment, a previous occupant had grown some horseradish.  Then came the rotavator for several seasons. Now one of our biggest weed problems is with horseradish - deep-rooting, hard to dig out, and everywhere in the allotment.