[TPKIRK]

I have a lot of weeds which are taking a lot of effort to remove because a lot are really deep routed.
I am enjoying getting them out, but i think i will be bored if i carry on having such slow progress for a long time.

I am worried that if i use any weed killers that i won't be able to use the ground for quite some time.
How long does it usually take to kill the plants, and how long after can i start planting?

Cheers!

[allotmentor]

The general recommendation for glyphosate is two days but if you want to make sure that it has had time to be transferred to the roots (from where it can kill the whole plant) from the leaves, it may be worth waiting 3-4 days before damaging the above-ground parts of the plant - glyphosate's action relies on the plant actively growing after application and you may not see any effects for a few days and it may take a week or more for the plant to die.

Don't forget that you can also deal very effectively with weeds, without chemicals, by covering with black plastic or something like cardboard or weed membrane covered with a good thick mulch. If you did this on part of your plot, and hand-weeded and planted the rest this year, you could then swap over next year, by which time any perennial weeds should have died...you might still have to hoe off any annual weeds that spring up from seeds in the soil when you uncovered it though.

[TPKIRK]

I had no idea that worked so quickly, i thought i would be waiting months before being able to use the soil.

You mentioned glyphosate, would you suggest i use this and do you know how much i would need to weed a patch approximately 90x30ft?

[simonwatson]

With glyphosate you can use the ground very quickly, as any that doesn't end up on the leaves of the plant will end up adsorbed (stuck to) soil particles and so won't be absorbed by subsequently planted plants. It takes a couple of weeks to kill the target though.

[allotmentor]

Glyphosate's certainly the least nasty of the weedkillers, although the jury's still out on whether it's completely safe. What I perhaps should have mentioned  is that you may have to do one or more repeats on larger/deep-rooted weeds (dock, bindweed, etc) and it won't kill everything (eg. horsetail)...you could always just dig the survivors out. Application rates will depend on the product I would think - an excuse to visit the garden centre?

[TPKIRK]

I would be more than happy to dig out the deeper tougher ones as long as it takes down quite the bulk of it.
With the risk i wouldn't mind so much as i would assume the risk is low.

Typically what is the price of Glyphosate? (Don't wanna get ripped off or buy the wrong stuff)

[allotmentor]

I reckon you'll nee about 10l of normal strength (c10g/l) glyphosate to treat your roughly 300m square plot which would probably cost you £30-50 if you bought packs (e.g Tumbleweed/RoundUp) with a sprayer built in...but do double chcek the active ingredient to make sure it's only got glyphosate in it e.g:http://www.primrose.co.uk/-p-45644.html?adtype=pla&kwd=&gclid=COWb_5ro2bcCFc3HtAodS0oAMA. If you're prepared to mix and spray it with a backpack (or similar) sprayer, you can probably get it for <£20 e.g: http://www.millracegardencentre.co.uk/garden/weedkillers-plant-food/weedkillers/glyphosate-concentrate-1l.html

[Lincolnshire Floyd]

I have a lot of weeds which are taking a lot of effort to remove because a lot are really deep routed.
I am enjoying getting them out, but i think i will be bored if i carry on having such slow progress for a long time.

I am worried that if i use any weed killers that i won't be able to use the ground for quite some time.
How long does it usually take to kill the plants, and how long after can i start planting?

Cheers!

Some good advice already so hardly anything to add. Put it this way.....if you sprayed a plant with glyphosate and then went and had a cup of tea and then suddenly realised that you'd made a mistake and wanted to keep it....and doused it with water to wash it off you would be too late. I know that from experience so I've got that t shirt. Some plants are more susceptible to it than others. Don't let it get anywhere near gooseberries as they will keel over just from the thought of it.
The waiting time is basically to let the weeds wilt so that you can dig them in or scrape them off although that is not really necessary either. But as somebody has already said I would give it a couple of days just because that is what it 'says on the tin'.
And watch out for drift if you want to get on with your neighbours.

[willp]

I reckon you'll nee about 10l of normal strength (c10g/l) glyphosate to treat your roughly 300m square plot which would probably cost you £30-50 if you bought packs (e.g Tumbleweed/RoundUp) with a sprayer built in...but do double chcek the active ingredient to make sure it's only got glyphosate in it. If you're prepared to mix and spray it with a backpack (or similar) sprayer.

I would suggest avoiding the built in sprayers and sprayers in general unless you can spray on an absolutely windless day. You`ll risk getting some on wanted plants and you`ll make enemies on the plot extremely fast(and not totally unjustifiably either) if it goes on anyone elses veg.

A special (bright red so you don`t use it for anything else) watering can is a good alternative and is actually very quick to use.

Will

[allotmentor]

@willp makes a very good point about wind/spray drift. The problem with watering it on is going to be making sure the solution contacts the leaves of all plants...as @simonwatson pointed out, it's not going to do a lot once it hits the soil. @willp - what application rate/concentration in your red can did you use? I guess you could always use a combination of spray (on a windless day) on most of the plot except the edges and then do them with the watering can?

[Yorkie]

Glyphosate is said to be inert on contact with the soil.

This means that there is no specific replant delay on soil.

However, in order to be effective on a plant down to the roots, I usually allow 10-14 days for the chemical to work its way through the system, and not 2-3 days.

[Nobbie]

@willp makes a very good point about wind/spray drift. The problem with watering it on is going to be making sure the solution contacts the leaves of all plants...as @simonwatson pointed out, it's not going to do a lot once it hits the soil. @willp - what application rate/concentration in your red can did you use? I guess you could always use a combination of spray (on a windless day) on most of the plot except the edges and then do them with the watering can?

It works well when watered on, just use a fine head on the watering can. I found it a lot quicker to apply than by sprayer and it was very effective, particularly where there is a lot of vegetation on the ground

[Totty]

Always better to spray, you only need to mist an area to get a couple of droplets on the weeds and that's all it takes. Wait until you can visibly see the weeds dying, then I strim it and turn it over and plant.

Totty

[stainesbloke]

With Roundup (glysophate) you can use the soil quite quickly after application. I sprayed the couch grass infested part of my new plot, waited 3 weeks to be sure everything was dead, then rotavated, manually digging out all the pieces of dead roots. Then I planted stuff which is all doing fine.

[TPKIRK]

Thanks for all the information guys, and sorry i took a while to respond.
I have had a quick look and found thishttp://www.amenity.co.uk/total-systemic-weed-killers/rosate-36-5l-glyphosate.html?utm_source=google&utm_medium=organic&utm_campaign=google_shopping&gclid=CKGawuir4bcCFXMPtAodomQAdw

Is this agood price? From reading the description it will need a very small amount, but i would like to save some too.