Topic: Weed suppression - black plastic?

[Sago]

I've just taken on an allotment and it's quite neglected. The person who showed me round suggests strimming it and covering much of it in black plastic to kill off the weeds at first and then working it bit by bit. I'm not sure this is what I want to do but if I did I'm not sure what to use - type of material, thickness etc..

I'm also not sure if it's too late to plant veg crops for this year. I've had a small garden veg patch for years and wouldn't normally be thinking of planting at this time of the year, but the allotment is much sunnier and as I'm in London I expect it's generally quite warm too.

Thanks

[claybasket]

Hi Sago, our first lotty had thick blk /plastic covering it and it did kill of some of the weeds but it was bad with thick brambles! so we turned the plastic back 2ft at a time and my oh dug and I weeded and planted as I went, we soon got through it doing a bit at a time, you can plant sprouts cabbages ,salad things ,if you bye it in you'll get more growing time get going . ps good luck clay.

[Jayb]

Hi and welcome to A4A Sago 

Covering the ground will stop most weed growth so if you are tackling a little bit of your plot at a time it keeps the covered part in check while you get on and make a bit of ground usable.
I'm just trying to get a piece of overgrown ground ready for planting this autumn and the remainder next spring. I've strimmed the long grass and I've covered it with cardboard, which will get a topping of grass clippings as and when I have them. The remainder of the area has been covered with I think it's called 'Mypex' it's a water porous ground cover to prevent the weeds growing. Hopefully come late summer autumn part of this will be ok to work and I can remove any perennial roots etc before planting.

[craggle58]

A fellow plotholder uses black plastic all the time to suppress weed growth and not just for ground clearance. He plants all veg in holes in the porous plastic (except potatoes). I am not sure how good this can be for the soil. Does anyone recommend this way of growing veg? For my own part I think that it is a lot of trouble and effort to avoid a bit of weeding.

[antipodes]

Cardboard is good and free :-) 
If you clear some of it now, you can still sow French beans, lettuce, late carrots (like Autumn King), beetroot, turnip, and various cabbages and caulis for the winter and in July start the Asian greens, swiss chard etc. Now is a good time to plant out leek plants (you can buy them in bunches on markets and in garden shops) also.

[BarriedaleNick]

Welcome to the site Sago!

At least looking at your site at this time of year will give you a good idea of the types of weeds and plants growing!  I guess there are a few approaches to clearing an overgrown plot.
Some people will just napalm the whole plot with Roundup, give it a few weeks and then strip back, dig etc.  However you risk killing anything nice lurking under the weeds and not everyone likes covering the plot in roundup.
You can of course try and cover with some sort of membrane or sheeting to kill off the weeds.  This may take some time and may prove to be expensive.  In my experience weed suppressing membrane doesn't always work well - it tends to let couch grass and bindweed through (unless I have a dodgy batch!).  If I was going to go down the cover route I would use some thick cardboard weighted down.  It is pretty organic, does the job and wont be impossible to remove!  It is surprising though how many perennial weeds will survive a period of cover - it will stop them growing but doesn't mean it will kill them

I would tend to go for a mix of approaches but there is nothing like a bit of digging to get one familiar with the soil and weeds. So I would start with digging out some small areas so you can at least get some stuff in this year and I would cover other areas with cardboard so the weeds dont grow too much.  Then you can work your way down your plot saving any weedkiller for any real nasties!

There are still plenty of things to get going this year - esp if you can find some plug plants in the garden center.  Even with out that you can still get a start with lettuce, radish, beetroot, dwarf beans amongst other and of course there will be garlic, onion sets and any overwintering stuff to go in as well.

[Russell]

A few years ago I took over two patches of land at this time of year with lots of perennial weeds, particularly couch grass. When I started to dig the weeds out I nearly lost the will to live. it was such hard work.
I decided to leave the second patch alone until the next spring and concentrate on the first patch which was a right handful.
The second patch was occasionally strimmed meanwhile. When time came to clear it, the same perennial weeds which had been so fearsome and hard to eradicate in the first patch were easily dealt with. Occasional strimming seemed to quite knock the stuffing out of them.

[Sago]

Thanks everyone - I think I get the picture. If I've understood I should cover with myplex/cardboard/old carpets until the weeds die back and then dig it over in chunks, planting whatever as I go.

So I had my first session there today. The good news is nearly 3kg of gooseberries - jam made and the rest frozen in batches - and enough blackcurrants for a small crumble, plus a few raspberries. There will be blackberries by the kilo too in maybe 8 weeks time - though of course that means a lot of brambles need removing too.

The bad news is when I tried a bit of digging I couldn't even get the spade into the matted grass for quite a while, so I don't think digging it now is the right idea. Or should I simply persist and clear a smallish bit at a time?

Or should I hire a rotavator  - about £35 for a day - and just turn it all over now and then put the myplex on top of that?

Thanks

[Borlotti]

Not carpet.  Need some rain and then it will be easier to dig.  After digging it all up when it was banned from our allotments I will never use carpet again.

[craggle58]

I totally agree about carpet. When I first got my plot it took weeks to get the half buried carpet out. Still finding odd bits years later.

[GrannieAnnie]

No carpet. What a pain to remove later and things can still grow on top of it, things you don't want, that is.

I have really become enamoured with putting down layers of wet newspaper and cardboard to kill the weeds/grass then adding layers of manure, cut seed-free weeds and vegetable matter (lasagne gardening). Then plant in holes cut through those layers. It enables getting some flowers/ tomatoes/ peppers etc started and by the end of the season the earthworms are moving into the papers and making some fine soil. By next year it is just dandy to plant in.

[Sago]

Thanks for the replies re carpet, cardboard and newspaper.

What about using a rotavator? Any views?

I've got about 70 sq metres to cover straight away, and don't have a clue where I could get so much cardboard. We don't read newspapers anymore so that's not an option.

I'm happy to cover it and leave most of it over the winter to improve, but I'd also like to do some planting and it really doesn't look like I could do that with a spade through the matted grass. I hadn't thought about rain - but apart from a time last winter it doesn't rain very much here in SE London.

Thanks

[BarriedaleNick]

Rotatvators are fine for breaking up soil but you really have to make sure you have cleared the site first or you will end up chopping lots of weed roots into bits that will just grow again.

[Redalder]

We used a rotavator to clear our 1/4 acre plot which was full of couch and fireweed. We ran it over and then raked the chopped weeds out, repeated this several times, planted up fairly sparsely and then over the rest of the season went round pulling up any weeds growing in the by now fairly loose ground. We repeated this the next year and after that we were as under control as one gets and used the rotavator to turn it over each spring. Now moved to a much smaller veg plot and the rotavator has been retired.

[craggle58]

I Agree with BarriedaleNick. Only rotivate after thoroughly clearing the site by hand first. Rotivating a weed covered plot just does a very efficient job of evenly redistributing the weed. Unfortunately there is no more effective alternative than the initial back breaking slog of clearing the plot by hand. It sounds really tedious but is actually very satisfying when completed.

[ancellsfarmer]

I'm at this stage with my "new "plot. Its a couple of chunks of an old established walled garden, and sometime nursery. Between the areas I have ground elder, couch grass, nettles, brambles, root suckers from prunus and blackthorn  and more molluscs than my share.
So far all areas have been treated to Weedol2, and the worst areas, glysophate. 70% dug over since May 8th and planted, except an area for brassicas which had the spray and then limed and the top "grubbed" off with a mattock before planting . This may be sprayed again with glysophate  as the next crop is prepared for, probably early spring.but only if necessary.  Meanwhile, any errant shoot is hoed and hopefully control maintained.
I have a rotovator rusting in the shed but its only used for seed bed preparation on clean ground.
Seriously, digging is a basic routine, not servile punishment and the ability to bury, 30cm deep all the " trash" while introducing organic material as FYM, &or compost is the norm.
I also use no-dig when building up raised salad beds, etc but only after deep cultivation in prior years.
It just depends on how determined you are to get the best for your efforts, obviously those with impediment must do the best they can but for the majority, there is no short cut that will really give the full result.

[Sago]

Thanks everyone - I'm starting to get the idea. I've ordered the black plastic to cover the ground and started digging an area yesterday to plant now - with the fork not the spade. This was quite easy, and the soil looks really good - much better than the garden. I'll cover most of it by early next week I think. My next neighbour turned up and gave me a courgette plant, and another offered strawberries, though I'm not quite ready for them yet. Next week a friend is bringing 2 rhubarb crowns and I think some pumpkins - not sure. I'll try to find some french beans in the next few days, and put in some salad crops. So this year's small plantings will be all be in soon.

I'm now wondering about the brambles. There's a huge patch of brambles and nettles at the top end  - about 18sq metres  - under the trees, with what look like old compost heaps, and various abandoned buckets and bins all buried in there. No crop plants mixed in. I asked my neighbour who said it hadn't been worked for at least 2 years, so I expect I'll need to find out if the compost is any good.

To deal with the brambles I think I need to cut them all back to say 30cm and then use a strong weedkiller to kill them off. Is this right? I'm also not sure how this fits with covering the ground - for the nettles etc. After spraying can I cut them right down and cover, or will they grow through the plastic. Perhaps it's better to let them die off and cope with the other weeds around there as and when for a few months they continue to grow through the plastic?

I also have brambles next to and among my fruit bushes and am not sure how to deal with these. As I sad earlier the gooseberries and blackcurrants seem quite productive so I don't want to simply kill the lot off. Is there a selective weedkiller?

Thanks

[chriscross1966]

Unfortunately not, even ion the professional world I doubt there is something that will kill brambles and not blackcurrants...

[ancellsfarmer]

I'm now wondering about the brambles. There's a huge patch of brambles and nettles at the top end  - about 18sq metres  - under the trees, with what look like old compost heaps, and various abandoned buckets and bins all buried in there. No crop plants mixed in. I asked my neighbour who said it hadn't been worked for at least 2 years, so I expect I'll need to find out if the compost is any good.

To deal with the brambles I think I need to cut them all back to say 30cm and then use a strong weedkiller to kill them off. Is this right? I'm also not sure how this fits with covering the ground - for the nettles etc. After spraying can I cut them right down and cover, or will they grow through the plastic. Perhaps it's better to let them die off and cope with the other weeds around there as and when for a few months they continue to grow through the plastic?

Cut back the brambles , about 150mm above the ground. Use either a "flasher"(or machette) and drag the tops away. Walk over the area and clear the debris, buckets etc. You can dig out the main roots, with a spade and a mattock. Let a couple of weeks pass and then survey the re growth. Try to identify what has popped up and decide whether to spray( with glysophate ( for couch grass, bindweed, ground elder and soft brambles and green weeds) or whether to dig over as previously done on planted area. Possibly consider this as an area for preparation for a "flying start" next Spring. If you can get it clean in time, you might do well to green manure it , with mustard or wheat. If the old compost heaps are turned over, you will discover anything untoward( such as roots from couch or bind weed), Sort, sieve and spread. You can also restack as layers in a new compost heap if you find part rotted woody stems e, prunings etc. This will not only introduce vital microbes to the new heap, but also hold open and aereate the heap. Remember its best also to turn the heap at intervals(about 10 weeks?)

[Robert_Brenchley]

If the brambles are too well established, you could cut them back to ground level and put black plastic over the whole lot. Cut back anything which emerges from underneath, and leave them till they're dead.