The Accidental Smallholder Forum

Smallholding => Land Management => Topic started by: chrismahon on October 28, 2019, 07:24:08 am

Title: Weed control by flooding
Post by: chrismahon on October 28, 2019, 07:24:08 am
We have a small area, perhaps 15 m2, which looks like it was once a pond. Over time it has silted up and the rainwater that it once collected has been taken by a vegetable plot constructed on the bank above it. This tiny area is a problem with weeds that are in soil too deep to dig out- brambles, creeping thistle, dandelions and dock. I've tried, but they keep coming back. I won't use weedkiller and I know that using a membrane will be a haven for field voles which the foxes (and our dog) will try to dig out.


With Winter coming up we will have plenty of water overflowing the butts. I wondered if an alternative to continually cutting and digging would be to flood the area by pumping rainwater so keeping it boggy for 3 months. Would this cause the roots to rot and die? Does anyone have these weeds in boggy areas? The land here is generally bone dry for many months and the aforementioned weeds survive drought well, but will they survive under water?
Title: Re: Weed control by flooding
Post by: landroverroy on October 28, 2019, 04:13:04 pm
Well I guess they have 2 chances - they'll either drown or not. But as these weeds do not normally flourish underwater, I would imagine you'll have a good chance. What about putting down a weed membrane before flooding as well?
Title: Re: Weed control by flooding
Post by: Fleecewife on October 28, 2019, 05:22:59 pm
I think they would need to be drowned for longer than 3 months, as that happens in nature and the weeds come bouncing back in spring. Couch roots need to be drowned in bucket of water for a year before you can safely add them to a compost heap.   By flooding, you would though kill off any creatures such as worms, soil bacteria, etc and make for a dead area with no oxygen in the soil.
I found that having a bog garden is impossible, as it quickly gets taken over by noxious weeds and grass which can't be weeded out.


Is there perhaps still a waterproof membrane in the bottom of the ex-pond, deep down (about 3 feet or so?  If so, then you could dig out all the existing soil plus weeds plus membrane, and start afresh.  Just a hope.


I was going to suggest covering the area for a couple of years, but the brambles would still poke through I think.
Title: Re: Weed control by flooding
Post by: sheeponthebrain on October 28, 2019, 06:58:18 pm
why not blast graze it all spring summer and strim anything thats left. if it was once a pond then flooding it will only give the old weed seeds from the pond a chance to grow
Title: Re: Weed control by flooding
Post by: arobwk on October 28, 2019, 07:03:39 pm
Not very optimistic remarks so far !
Some various thoughts: 

Would Spring/Summer flooding be more effective than Winter flooding (!???) - I have clients with an old punctured membrane pond which still stays quite "boggy" all year round;  I have to deal with a few nettles around the margin, but no invasion of nettle or bramble etc into the boggy bits after several years of membrane failure;

If not interested in re-planting anytime soon, maybe add a good load of vinegar and, if desparate, salt as well (both will obviously wash out eventually);

And, of course, weed membrane will help while also keeping the foxes and doggie happy !!;

And just keeping at it, very very frequently, with a strimmer or burner or similar will EVENTUALLY work as well.

So, I don't really have a clear answer  :(
Try everything and double/triple/quadruple up methods to whatever extent possible is all that I can suggest (if you are adamant that no commercial herbicides will be used on your land - ever)  :-\


 
Title: Re: Weed control by flooding
Post by: chrismahon on October 29, 2019, 06:58:37 am
Unfortunately flooding in Spring and Summer isn't possible without using expensive tap water as all the rain water goes to the vegetables. Our tap water contains a lot of Chlorine (undrinkable) so that may affect the soil?


There won't be a membrane down there- were looking at a 50+ year old farm pond.



Sounds like flooding won't work. Perhaps I'll have to dig deeper? I've been streaming it flat for a year to no effect. Can't use a burner as it gets very dry here and the fire risk will be too high. I think that's one reason why hay is cut so early as we can get dry lightening strikes in Summer.
Title: Re: Weed control by flooding
Post by: doganjo on October 29, 2019, 05:10:34 pm
Wouldn't work.  The garden of the house I've just bought was saturated.  Had to get new field drains installed, a roadside manhole, gullies(branders to the northern scottish amongst us) at a cost of about £2K.  As well as the reduced sized rhododendrons and elder bushes, there were nettles, thistles, reeds, ragwort, brambles, dandelions and goodness knows what else.  So the excess water from the underground springs did them no harm whatsoever.  I am hoping that intead of spongy grass my rhoddies and elders will now flourish, and I'll, be able to plant fruit bushes and climbers along the fence that my gardeneres should soon be able to complete when it dries out enough for postcrete
Title: Re: Weed control by flooding
Post by: arobwk on November 01, 2019, 04:48:51 pm
@chrismahon   A year won't do it without herbicide:  I can vouch from experience that repeat and 'religious' strimming or slashing and as much pulling as you can manage (half a root out is better than not giving it a tug at all) will get you there in the end over a few years.  At grave risk of teaching granny, just don't let any broadleaf stuff put on enough foliage to allow it to put energy back into the roots. 
 
Title: Re: Weed control by flooding
Post by: chrismahon on November 02, 2019, 06:59:47 am
We've just watered some newly sown grass seed (100m2) and now realise that we will need to do a lot of water pumping from the butts to get enough to saturate that small area- probably less time to keep digging and slashing anyway. An alternative idea is to buy another chicken net and fence off the area to allow us to use weedkiller without the risk to dog, chickens and wildlife.
Title: Re: Weed control by flooding
Post by: doganjo on November 03, 2019, 12:20:12 pm
We've just watered some newly sown grass seed (100m2) and now realise that we will need to do a lot of water pumping from the butts to get enough to saturate that small area- probably less time to keep digging and slashing anyway. An alternative idea is to buy another chicken net and fence off the area to allow us to use weedkiller without the risk to dog, chickens and wildlife.
One of my tradesmen has access to weedkiller that is safe for farm animals - so would that also be safe for .domestic ones?  He seems to think it is and has used it extensively here with great success.  No idea what it's called though.  But most 'off the shelf' stuff says it's safe for pets after being dry for 10 minutes anyway