Growing potatoes - No Dig method on weedy ground

[Wonderfulcheapfalafel]

Hi, this is likely to be first of many posts asking for advice on various things to do with allotment growing! My new plot is covered with couch grass so I am planning on putting a plastic mulch down to kill as much as possible this first year. I'm going to try the 'no dig' method, and plant straight through the plastic in one area for a crop of potatoes.

Just trying to work out which variety (I think I want a second early) and when I need to start chitting the seed potatoes for this. I'm going to start in a space big enough for about 20 plants...

Any advice, especially from anyone else who practices No Dig, would be appreciated!

Having cleared a lot of plastic from my plot -
whixh will never be clear… - do think twice about plastic mulch. I inherited a horrendously weedy plot, and potatoes were a great weed suppressant. I covered w thick (3+) layers of cardboard, then about 4 inches of manure. Planted potatoes through the card (which actually I think was a bad idea - better on top) and then hand weeded while the plants were small. Once growing they pretty much out competed everything else - just a few v weedy thistles came through.

I agree this is a better plan for getting a plot up and running. Make sure the cardboard is thoroughly wet before you put the potatoes and mulch on.

Oh! I was planning on only leaving the plastic sheet there until no longer needed and then potentially re using, rather than just letting it degrade into the ground. My budget is pretty limited at the moment so can't really afford a big bulk of compost which is what I'd really like. Will potatoes out compete couch with just cardboard mulch? That would be great!

Cardboard every time. Big sheets, double thickness with staggered joints. If you can't afford manure you can cover it with anything you'd normally put on a compost heap. Where do you live? Think creatively about what local enterprises are likely to have bulk waste you can collect. Round here I get well rotted manure from local stables and wood chip from a joinery.

Couch is a pig to eliminate completely but cardboard weakens it to the extent it comes up easily.

There's no rush to start chitting yet, I'd be using the next few weeks to research potato varieties. If you buy the smallest size packs of seed potatoes you'll be able to try 3 or 4 different ones.

We do the same as pp, thick cardboard layer, I add raw wool from sheep fleeces I collect, then a thick layer of well rotted compost.

Potatoes are ideal for growing on areas infested with couch grass. They help to reduce its vigor.

We only use plastic sheeting to cover fallow to prevent annual weeds until we re sow the area.

Plastic is a nightmare, they weeds still come through and the plastic strings get completely entangled and you can never fully remove it. It’s a scourge on our apartment, wiser than couch grass. I also swear by thick wet card.

Thanks everyone, am annoyed at myself for ordering the plastic sheeting now! Just to clarify though, I'm using the thick black polythene type plastic sheet stuff, not the stringy weed suppressant stuff which I agree is a pain in the arse!

It's a big plot so I may just use it to cover the half I'm leaving for now ( starting small so I don't get overwhelmed!)

If you use the thick sheeting you have a watering problem, plus you basically kill the soil. Which feels good for weeds, but is not really any good…

my plot had the stringy stuff (aargh) and also a membrane stuff that has totally fallen apart, so I find centimetre to inch fragments everywhere.

how big is your plot? I would say get on w clearing just as fast as you can - otherwise it will be a job you do for years. I was totally astonished w how well the cardboard method worked for me - you do need SOMEthjng to go on it tho. I’d be inclined to put potatoes and then later squash everywhere this year, if it allows you to have a clear plot in a year.

I see your point with sourcing compost. As people have said the thick pond liner type polythene won't let water through-itd be great for putting on an area you're just not going to use at all this year though. And if you don't cut holes in it it'll reuse much better!

If you have very little mulch I've done bulb planter in weedy ground, potatoes in holes, cardboard, then a thinner layer of compost. You won't get the yield you'd get with weed free ground or a thick layer as there'll be more of a fair fight with the weeds, but you'll get some and you can remove weeds as you harvest. Honestly, it's all a bit of a trade off with available time and all worth a try!

Let the potatoes dig the ground for you. Mentally portion the plot, start with the potatoes them
move them across each year.

Lasagne planting is good- a layer of card, then sticks, then hedge clippings, then grass cuttings. It will break down eventually.

I would go cardboard.

But whether cardboard or plastic I wouldn't cut holes and plant through it - the weeds just grow through the holes.

Potatoes will do fine on top of cardboard - just a couple of handfuls of compost each to get them started then mulch with grass clippings, added a thin layer attached time so they don't get too hot.

You could definitely put your plastic on top of the half that you’re not using this year, and weigh it down with bricks or such instead of growing on top of it.

Agree with PPs - plant on top of, rather than through, the weed barrier. The roots of your plants will eventually grow down through the cardboard but the weeds underneath will struggle to grow up through it without sunlight. You can then add another cardboard layer on top each season. I’m a complete convert to no-dig and planning to try straw bales this season :)

The opponents of “no dig” claim that annual digging is necessary to control pest populations, that it works fine for a year or two, but after that pests build up to uncontrollable levels

I have sheets of Mypex (plastic woven ground cover) that I use with no problem, but only as temporary ground cover. Cardboard all the way though especially for new beds.

I never dig and never have and have no problem with pest build up.

I’ve started new beds in Virgin field by slicing and turning a thick layer of turf and planting the potatoes in the exposed soil then putting the turf over the top upside down.

the trick with woven plastic is to burn the cut edges, don’t just cut them. I have a little blow torch soldering thingy that I use which does the job, otherwise the frayed ends are a nightmare.

@MereDintofPandiculation
As an agriculturalist I can say that in the UK the only pests turning the soil really helps with are perennial weeds species. Digging may expose some larvae but it also reduces the beneficial fauna in the soil the cost is greater than the benefit in gardening terms.

We used to, and sometimes still do plough and dig to make it easier to plant larger areas, aerate the soil, clear the ground, and improve the soil structure for young plants. No dig methods bypass this with the use of weed suppressants and compost leaving the soil to retain it's natural structure and soil inhabitants to live their lives unhindered.

Allowing a plants natural defence mechanism to flourish is key to reducing pests attacks on plants. Healthy plants taste better too.

@MarkingBad Totally agree with you. Very glad to see you say this, as the post was followed by several saying “I do what the farmers do. They’ve been growing for centuries”.

Out of interest - I see that you don’t necessarily agree - what pests might those be?

Slugs, cutworms were mentioned.

Thanks @MereDintofPandiculation - slugs and curl grubs (our invasive pest equivalent to cutworms) are already at plague proportions in my garden, so I think I’ll take my chances ;)

Interesting, I've never heard of turning the soil as a control for either slugs or cutworms. I can only think that it is to clear the area of weed species that might harbour them.

It would also bring slug eggs to the surface, where they might dry out or be eaten by birds.

I grew new potatoes in a new large black plastic dustbin. I'd do that and use allotments for growing carrots, onions, salad leaves in the summer, tomato plants and herbs.