Weed Control

Seeding after weed killing - how long shall I wait?

 

Jim – A tricky one this

Weed killer can seriously affect the germination of seeds so it’s going to depend on what you’ve used. If you’re renovating and  killing the whole lawn with a glyphosate product then you could in theory seed the next day though you’d get better germination of your new seed after the old grass has died and been scarified to clear the lawn surface.

If on the other hand you’re using a selective weed killer on your lawn it will depend on how thorough you’ve been and what you’ve used. As a general guide it would be best to leave it at least a month but if time is important leave it a day or two and go for it, the chances are a reasonable proportion will germinate.

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Clover and thin grass problems

 

My back grass is never as thick and healthy as my front (front was turfed back seeded when I moved in) I treat with weed and feed, scarify etc but it just never thickens up.

I also am trying to find a specific product to target clover but can't seem to find one. Can you advise please?

Hi Chris

The fact that one lawn was seeded and the other turfed isn't the problem - turf is, after all, grown from seed! The main factors will be differences in soil, shade/light, grass species and mowing. Though you may mow each the same way, if the grass species are different from front to back then they need to be cut at different heights so read Good Lawn Mowing Practices.

In a way I'm glad you admit the weed and feed doesn't work, I hate the stuff! Clover likes low nutrient soils so it appears the 'feed part' isn't  raising nutrient levels enough and the 'weed part' isn't killing the clover! Clover is relatively  easy to kill so have a read of this paragraph on White Clover

To summarise, you seem to be on the right track and caring for your lawn but perhaps review your mowing get some good fertiliser into the soil and use our recommended weed killers for the clover. Other factors such as soil and shade may not easily be changed.

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Clumps of thick tough grass in my lawn

 

New lawn laid late last year. Turf looked ok, been mowing for a few weeks this year, looked ok. Now within two days of mowing, these thick clumps of grass are shooting up much quicker than the normal thin stuff and are a much lighter green. Looks awful. My wife has taken my belt and shoelaces so I cant do anything silly, but its driving me mad. Desperate of Dartford

Hi Dave

Did she let you keep the flame thrower though?

Sounds like a weed grass called Yorkshire Fog. Have a read, may not look similar being young plants but if the leaves are pale green, slightly hairy and very soft then that’s it so start digging or kill it with glyphosate..

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Controlling exotic or unlisted weeds

 

My lawn has been invaded by Pratia from an alpine rockery. It is well established in the lawn. Is there any selective weedkiller to control it? I have used Verdone 2, this doesn't seem to touch it.

Graham - Interesting question.

There are always going to be weeds that I classify as 'unlisted'. In other words, the species cannot be found against any particular weed control chemical. And remember, a weed is just a plant in the wrong place, ergo, there are millions of weed species!

You therefore need to try all the weapons available to find the best one. Sometimes the best one may only be modest control:

  1. There are other chemical groups available to you: Verdone is one so try Vitax and  Bayer Advanced
  2. Mow the grass on the high side - better for the grass and puts the weed in shade
  3. Iron or Ferrous Sulphate has always been used to exert some control over broad leaved weeds. Spray the whole lawn at the highest rate on a cool day with plenty of ground moisture. The grass loves it  and the weeds don't!
  4. As pratia is a creeping weed it will not like regular scarifying
  5. As with many creeping weeds they can often shoot from cuttings so make sure you collect all debris after mowing or scarifying

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I fed my lawn with a weed & feed treatment and it's now gone black!!!

 

Because I am new to gardening I was unaware that if I did not water the lawn within a couple of days, it would burn. The result being that 75% of my lawn has gone black. What can I do to solve this problem? James

I suspect you and several thousand others have done the same. Combined weed and feed products by their very nature need care and accuracy in applying which is why people give up treating the lawn because they see it as a hazardous excercise (and who can blame them)!

Unfortunately it is hard to tell at this stage what will happen as you may have killed the grass or it may just be damaged and therefore a temporary problem. Waiting to find out might also be a bad idea because weeds and weed grasses will start to take over the dead or damaged grass. I would therefore over sow with new grass seed to be on the safe side. You may need to water the lawn or wait for rain if the lawn is dry.

Hopefully you and others will take a different approach after such an experience by applying fertiliser as one treatment and a liquid weed killer as another treatment. This way as long as you have some soil moisture you don't need to water it in or worry about rain. Have a read of this section for fertilising, this section for weed killing  and you will find safe lawn care products in our shop.

Finally, learn from this don't give up. You've got brownie points for trying.

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Pasture grass

 

Lawn feed and weed is fine for broad leaved weeds, but I think my problem is 'pasture grass'. It is slightly lighter in colour than the lawn and starts to flower shortly after mowing. Is there anything I can do to get rid of them?

Hi Nick

Frequent or over use of 'feed and weed' can have a detrimental affect on grass - some species more than others. Have a read of About Lawn Weed Killers

To answer your question, the grass that has colonised your lawn is annual meadow grass - have a read of Rough, Couch and Other Lawn Weed Grasses

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Self-heal

 

I've applied selective weed killer on my lawn, but with very little affect against the above weed. I've attempted digging the blighter up, but because there is so much of it, I've given up....Any suggestions ?

Hi David

Killing last years tough over wintered weeds in these cool April conditions is going to be difficult. Try giving them a zap when they get some new growth on them - perhaps next month. The weed killer will kill it but expect resident seeds to keep throwing up new plants - self-heal is very persistent and it may be several years before you get real control.

If self heal is your main problem you could also use a ready to use weedkiller for localised frequent applications as you do need to keep on top of it.

TIP: Mow weekly when growth picks up - keep the mowing height on the high side.

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New lawn has weeds - when can I treat it?

 

Patrick – a very common situation

The answer is read the label on your weed killer. For Bayer Advanced give it 6 months before treating. For Verdone just 2 months is required.

Personally I’d treat around May for a lawn sown in autumn and I’d wait until August or September for a lawn sown in spring.

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Natural or Organic Weed Killer

I would like to use organic or natural weed killers on my lawn. Can you suggest anything other than vinegar?

Hi Melanie

You can use vinegar or a strong salt solution to kill weeds, the problem is it will kill any plant, grass included so it is not ideal for the lawn. If you are going to do this be very accurate and I would suggest 'painting' the solution on the weed. If your concerns are to reduce pesticide use for the environment then I would suggest using a lawn spot spray weed killer. This way it only goes on the weed with minimal impact on anything else.

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Controlling exotic or unlisted weeds

 

My lawn has been invaded by Pratia from an alpine rockery. It is well established in the lawn. Is there any selective weedkiller to control it? I have used Verdone 2, this doesn't seem to touch it.

Graham - Interesting question.

There are always going to be weeds that I classify as 'unlisted'. In other words, the species cannot be found against any particular weed control chemical. And remember, a weed is just a plant in the wrong place, ergo, there are millions of weed species!

You therefore need to try all the weapons available to find the best one. Sometimes the best one may only be modest control:

  1. There are other chemical groups available to you: Verdone is one so try Vitax
  2. Mow the grass on the high side - better for the grass and puts the weed in shade
  3. Iron or Ferrous Sulphate has always been used to exert some control over broad leaved weeds. Spray the whole lawn at the highest rate on a cool day with plenty of ground moisture. The grass loves it  and the weeds don't!
  4. As pratia is a creeping weed it will not like regular scarifying
  5. As with many creeping weeds they can often shoot from cuttings so make sure you collect all debris after mowing or scarifying

Do let me know which does best. 

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Bind Weed

 

We've got field bindweed on our lawn, I've heard glyphosate removes bind weed but will damage the grass, is there any common lawn weed killer that I can use to control this particular weed?

Hi Laura

Convolvulus (bind weed) can be killed with any of our selective grass safe weed killers. It may require a few treatments as a lot of the growth can be underground where the spray won't reach.

Hope that helps

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Eradicating Green Alkanet or Evergreen Bugloss in my lawn

 

Kathryn

This weed as you probably know likes shady and damp areas and can have quite deep roots. As I have little experience of it you should try various control methods to give you the best or multiple control methods:

  • Many tall growing weeds can't tolerate frequent mowing. Some though can adopt a lower growing growth habit in response to frequent mowing. Try it.
  • Spray with a selective systemic weed killer. Though these are formulated for most native weeds it doesn't mean they won't work on this. Try Vitax and Verdone which are safe to use on the lawn
  • Final choice is hand weeding. You may need to do this repeatedly over a year because of the deep roots

Please let me know how you get on

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Can I rescue my lawn after spraying with glyphosate

 

I used accidentally Westland Weed Bust (contains Glyphosate on all of my lawn is there any way I could rescue the lawn. Please advise as soon as possible.

Hi Jan

As you've realised glyphosate also in Roundup kills everything including the grass and unfortunately there isn't alot you can do to stop the grass dying and the amount of damage will depend on how thorough you were when you sprayed! However, if you do nothing the chances are that the dead patches will become over run with coarse weed grasses and weeds. You need to re-seed the areas but to do this you may need to scarify the lawn first. Please read the section All About Lawn Scarifying which also covers over seeding with new grass seed. Do this in August or September when the heat of the summer has gone and after rain.

Finally, don't feel too bad, several thousand people do the same thing every year but make sure you have grass friendly weed killers on hand for the future.

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Birds-foot trefoil and clover

 

I have two weedkillers Vitax and Verdone but neither have touched Bird's-foot Trefoil in my lawn.  Some of the clover seems untouched as well.  Do you have any suggestions as to a better approach?

David

A good and timely question. Lets start with the easier one; Clover. Both products will kill it and the problem you are having is due to one or more of the following:

  • This year (2011) is the driest on record and as the weed killer works by over stimulating growth a lack of moisture reduces effectiveness
  • You say some clover remains - without seeing it, the clover has possibly been missed by the sprayer or was young growth not exposed at the time of spraying. To get effective control repeat applications are often required and unfortunately your treatment does not stop new plants establishing
  • Check your concentrations

Consider your next application after rain and fertiliser. For small surviving patches try Ready to Use Verdone. Please persevere as you can get very good control of clover with these products though patches will re-occur next year from May onwards.

Your other problem is best answered by reading this page on Birds-Foot Trefoil. It's not easy to kill so I'm not surprised you're having difficulty nor is it a listed target weed on either of the products.

Hand weeding works if you haven't got too much otherwise regular targeted applications of Ready to Use Verdone offers some hope. Because frequency is important you must keep the spray confined to the weed and off the grass. Apply perhaps every 4 to 6 weeks. Keep to the recommended dose and don't over spray or else you'll kill the grass. When the weed starts looking sickly don't treat anymore as the chances are it's on the way out.

Finally, most trefoils are very persistent and complete erradication is virtually impossible. The best you can hope for is perhaps 90% control in any year.

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What order for fertiliser and weed control

 

I have read quite a bit of your site but not too sure about order.  Moving into new house with a lawn that was seeded in April 11. Has been cut but not fed or weeded. Have spot weeded worst offenders. Lots of Yorkshire fog (whichI can live with for now). I'm on board with separate weed and feed. Which do I do first and  do I use an autumn feed please? 

Hi Guy, glad to hear you're converted.

It's not critical which way round you do it and of no consequence if you are just spot spraying individual weeds.

However, if you want to spray the whole lawn for weeds (rather than spot spray) then fertilise first and wait one to two weeks before weed killing. You will find this page on How to Kill lawn Weeds will give you the guidance you need.

As regards fertiliser you will find that the Fertiliser Products in our shop are always in seasonal order and at present Autumn is first so that's the one for the next couple of months.

Hope that answers everything

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How to get rid of "mind your own business" in a lawn?

 

Gerry, the short answer is with difficulty.

Boiling water, strong salt solution and glyphosate all work but should NOT be used on the lawn. You are therefore left with cultural control which means keep the mowing height up and rake out and overseed heavy infestations. Maintaining a good lawn care regime will also help so spend a bit of time reading our advice sections.

Perhaps not the answer you're looking for but you can make a considerable difference this way.

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