2015 Lawn thread
Discussion
jagnet said:
Was a pre seed fertiliser added with the new turf? If not, then a 6-9-6 starter one to promote root growth would still be beneficial. Avoid adding high nitrogen fertilisers to the new turf until it's established.
Blood, Fish and Bone. Cheap as chips and all natural. Stimulates root growth.All my efforts seem to have taken a turn for the worse. My entire lawn, which was making very good progress, is now covered in Poa Annua and I have a horrible feeling it might have been from the seed I over seeded with from B&Q about a month or so ago as it is so evenly spread throughout the lawn.
As far as I can tell there's little I can do to control this weed grass and it can't be selectively targeted.
Any advice would be greatly appreciated.
As far as I can tell there's little I can do to control this weed grass and it can't be selectively targeted.
Any advice would be greatly appreciated.
Poa annua is a pain in the proverbial. Cultural control is a slow but effective way to deal with it. It thrives in a disturbed environment but dislikes stress, so avoid excessive raking and cutting too short causing scalping.
Versus the finer fescues, Poa annua has shallower roots so will be prone to drought sooner - avoid over irrigating, let the ground dry enough to stress the PA without stressing the fescues and allow their competitive abilities to crowd out the PA. Avoid over feeding - the slow growing fescues need far less nitrogen than the PA. PA is a prolific seeder and will take advantage of any bare ground quickly so over seed any bare areas asap with desirable grass seed.
I would try to pull a few Poa annua clumps whenever I'm out on the lawn and collect grass clippings if possible to avoid spreading the new seeds.
There was mention of chemical control earlier in the thread (a product called Rescue iirc?), but I've not tried that.
Short of killing everything off, there's not much you can do this year other than manage the situation. Get all your end of season scarifying, raking, overseeding etc done this autumn rather than next spring to give the finer grasses much longer to develop whilst the PA dies back and before its seeds have chance to germinate next year.
There's some excellent articles by Henry Bechelet (The Disturbance Theory), written from the perspective of managing Poa annua in favour of fescues and bents on golfing greens but imho equally useful to the home lawn enthusiast:
Do Not Disturb
Changing the Nature of Your Greens
Food for Thought
Irrigation - The Tool of Agronomic Change
Rhubarb and Custard
Where I didn't get much chance to look after the lawn last year, Poa annua was able to get a foothold on the more trafficked areas and now I'm seeing just how much seed it produced in that time, so you have my sympathies.
Versus the finer fescues, Poa annua has shallower roots so will be prone to drought sooner - avoid over irrigating, let the ground dry enough to stress the PA without stressing the fescues and allow their competitive abilities to crowd out the PA. Avoid over feeding - the slow growing fescues need far less nitrogen than the PA. PA is a prolific seeder and will take advantage of any bare ground quickly so over seed any bare areas asap with desirable grass seed.
I would try to pull a few Poa annua clumps whenever I'm out on the lawn and collect grass clippings if possible to avoid spreading the new seeds.
There was mention of chemical control earlier in the thread (a product called Rescue iirc?), but I've not tried that.
Short of killing everything off, there's not much you can do this year other than manage the situation. Get all your end of season scarifying, raking, overseeding etc done this autumn rather than next spring to give the finer grasses much longer to develop whilst the PA dies back and before its seeds have chance to germinate next year.
There's some excellent articles by Henry Bechelet (The Disturbance Theory), written from the perspective of managing Poa annua in favour of fescues and bents on golfing greens but imho equally useful to the home lawn enthusiast:
Do Not Disturb
Changing the Nature of Your Greens
Food for Thought
Irrigation - The Tool of Agronomic Change
Rhubarb and Custard
Where I didn't get much chance to look after the lawn last year, Poa annua was able to get a foothold on the more trafficked areas and now I'm seeing just how much seed it produced in that time, so you have my sympathies.
Hi Jagnet, I've not pre-treated any of the soil before laying the new turf, just kept it well watered. The grass has never been fed, just cut at regular intervals. I'd put the turf down to re-model, as there had been two flower beds that were well past the use by date (and were the ex-wifes idea, so part of it was to remove the last remnants of her gardening aspirations). The garden is used by a dog that has toxic wee, so the grass will end up with patches, but I'd like to manage it the best I can. I'm not expecting putting green standard, but just presentable and looking cared for will do!
I can see the dog going stupid over blood, fish, bone etc scattered into the lawn!
I can see the dog going stupid over blood, fish, bone etc scattered into the lawn!
Blood, fish and bone can be an issue with dogs.
The grass burn from dog urine is down to the high nitrogen levels, which is why the dead grass is surrounded by lush green growth. The special rocks that you can put in their water bowls sometimes help a little but really the only defence is to dilute it down as much as possible as soon as they've been on the grass. Have a hose or a full watering can on standby. Any patches that do turn brown should be raked free of dead grass and over seeded. It's a never ending repair process so having a fast germinating seed mix is a good idea therefore luxury lawn ones with bents and fescues only aren't really suitable, but hard wearing and fast germinating rye grasses are. The ryegrasses are better able to cope with damage from the dog running around as well.
Any patch repairs during the summer are going to stand out, but an autumn over seed across the whole lawn with the same grass blend will help even it somewhat. Cutting high will also help hide colour and grass type variance. If you want a really green ryegrass to overseed with, Germinal's A26 So Green is really really green and with 60% ryegrass it's going to stand up well to use.
As for fertilisers, with soil that's going to be really quite depleted in nutrients, regular watering in of dog urine and frequent patch repair, I'd probably go for quite a balanced slow release one like the Lebanon 18-4-12 here which will also be fine to use on the new turf. That's a fairly big bag of it so smaller packaged alternatives would be fine so long as they've got reasonable proportions of P and K to N to help root development, stress resistance, etc.
I probably wouldn't worry about putting down a starter fertiliser on the new turf now if using the above fertiliser, but it might be handy to have some to hand to add a little to any patch repairs (although if you use them, the repair products like Miracle-Gro Patch Magic already have starter fertiliser added).
The grass burn from dog urine is down to the high nitrogen levels, which is why the dead grass is surrounded by lush green growth. The special rocks that you can put in their water bowls sometimes help a little but really the only defence is to dilute it down as much as possible as soon as they've been on the grass. Have a hose or a full watering can on standby. Any patches that do turn brown should be raked free of dead grass and over seeded. It's a never ending repair process so having a fast germinating seed mix is a good idea therefore luxury lawn ones with bents and fescues only aren't really suitable, but hard wearing and fast germinating rye grasses are. The ryegrasses are better able to cope with damage from the dog running around as well.
Any patch repairs during the summer are going to stand out, but an autumn over seed across the whole lawn with the same grass blend will help even it somewhat. Cutting high will also help hide colour and grass type variance. If you want a really green ryegrass to overseed with, Germinal's A26 So Green is really really green and with 60% ryegrass it's going to stand up well to use.
As for fertilisers, with soil that's going to be really quite depleted in nutrients, regular watering in of dog urine and frequent patch repair, I'd probably go for quite a balanced slow release one like the Lebanon 18-4-12 here which will also be fine to use on the new turf. That's a fairly big bag of it so smaller packaged alternatives would be fine so long as they've got reasonable proportions of P and K to N to help root development, stress resistance, etc.
I probably wouldn't worry about putting down a starter fertiliser on the new turf now if using the above fertiliser, but it might be handy to have some to hand to add a little to any patch repairs (although if you use them, the repair products like Miracle-Gro Patch Magic already have starter fertiliser added).
Poa annua... Hmmm... That's another candidate for what I've got.
For many years I've identified the coarse, velvety bluish grass in my lawn as Yorkshire Fog, but I think that identification is wrong since it seems to disappear in winter - hence my weed grass must be annual.
To be honest, mine could be hairy crabgrass or Poa annua - I can't tell the difference from Google images. All these broad-leaved weed grasses look the same to me!
Either way, I now think that "Rescue" would be a waste of a lot of money against annual grasses. Sure, I guess it would kill off this year's crop, but their seed bank would be left in the ground to germinate next year.
I'm now banking on a pre-emergent herbicide, which targets newly emerging embryo plants as they germinate. The one I've ordered is Scotts Halts Crabgrass and Grassy Weed Preventer, which strangely doesn't seem to be available in this country but is being delivered from the U.S. I won't know until next year whether it works, because the time to use it is early spring.
The other thing to try, which I'm experimenting with, is sodium bicarbonate. It definitely kills the weed grasses but the jury's still out on whether it destroys the proper grasses or just weakens them a bit. I suspect it's a case of getting the dosage right, so that the broader leaves of the weed grasses catch more of the bicarb than the finer grasses - in much the same way that some granular weedkillers work. I'll report back in a few weeks. One thing is for sure: you only need a very light dusting of it, and it works in just a few hours!
For many years I've identified the coarse, velvety bluish grass in my lawn as Yorkshire Fog, but I think that identification is wrong since it seems to disappear in winter - hence my weed grass must be annual.
To be honest, mine could be hairy crabgrass or Poa annua - I can't tell the difference from Google images. All these broad-leaved weed grasses look the same to me!
Either way, I now think that "Rescue" would be a waste of a lot of money against annual grasses. Sure, I guess it would kill off this year's crop, but their seed bank would be left in the ground to germinate next year.
I'm now banking on a pre-emergent herbicide, which targets newly emerging embryo plants as they germinate. The one I've ordered is Scotts Halts Crabgrass and Grassy Weed Preventer, which strangely doesn't seem to be available in this country but is being delivered from the U.S. I won't know until next year whether it works, because the time to use it is early spring.
The other thing to try, which I'm experimenting with, is sodium bicarbonate. It definitely kills the weed grasses but the jury's still out on whether it destroys the proper grasses or just weakens them a bit. I suspect it's a case of getting the dosage right, so that the broader leaves of the weed grasses catch more of the bicarb than the finer grasses - in much the same way that some granular weedkillers work. I'll report back in a few weeks. One thing is for sure: you only need a very light dusting of it, and it works in just a few hours!
Edited by Dr Mike Oxgreen on Thursday 28th May 07:59
Dr Mike Oxgreen said:
I'm now banking on a pre-emergent herbicide
I'm tempted to give that a go in the spring as well since you mentioned it before. I think it'll depend a lot on how much moss develops over the winter and whether I'll need to over seed much come the spring. If it's just a few patches I can put the pre-emergent down over the bulk of the lawn and avoid the seeded areas.I reckon your theory about the sodium bicarbonate is spot on, with much greater leaf area on the weed grasses to make contact. My neighbours already think I'm nuts spending so much time on the lawn, I doubt they'd bat an eyelid watching me trying to leaven the lawn
I think this is my first post in this thread, have been reading for a few months since we bought our first house and inherited our first lawn. Previous place was sleepers, gravel, decking, bark and patio!
This was the photo from the agent when we viewed the house..
The day we moved in, the grass was really yellow and 'flat' as if a tent or similar had been on the grass but there wasn't actually a tent mark. Weird. There was also LOADS of moss. Anyway, we applied a 4 in 1 type moss killing product and after raking we were left with this..
After a couple of months, a couple of types of seed, some topsoil, some fork action and its now looking like this..
A few thin patches to sort, but its looking pretty good!
This was the photo from the agent when we viewed the house..
The day we moved in, the grass was really yellow and 'flat' as if a tent or similar had been on the grass but there wasn't actually a tent mark. Weird. There was also LOADS of moss. Anyway, we applied a 4 in 1 type moss killing product and after raking we were left with this..
After a couple of months, a couple of types of seed, some topsoil, some fork action and its now looking like this..
A few thin patches to sort, but its looking pretty good!
Edited by Max M4X WW on Thursday 28th May 12:47
GP335i said:
PH lawn gods, how do I fix this mess?! I left it for about 3 weeks without a trim and it took some effort to cut. The grass felt almost waxy.
The waxy feel was most likely due to the lack of rain/watering. Aerate the soil with a fork inserted at an angle and lift. This will allow the compacted soil to be able to absorb water better and introduce air for soil bacteria to flourish. Water well for at least an hour a day, but not so that it puddles. In a week report back. Then a good weed and feed.
thouse.Max M4X WW said:
After a couple of months, a couple of types of seed, some topsoil, some fork action and its now looking like this..
A few thin patches to sort, but its looking pretty good!
That's a noticeable improvement to put it mildly A few thin patches to sort, but its looking pretty good!
Shade is going to be your biggest headache looking at that, hence the large amounts of moss that was there and the slower germination nearer the fence. Keep it on a high cut especially over winter. Have you used shade tolerant grasses in your mix?
Philemon said:
GP335i said:
PH lawn gods, how do I fix this mess?! I left it for about 3 weeks without a trim and it took some effort to cut. The grass felt almost waxy.
The waxy feel was most likely due to the lack of rain/watering. Aerate the soil with a fork inserted at an angle and lift. This will allow the compacted soil to be able to absorb water better and introduce air for soil bacteria to flourish. Water well for at least an hour a day, but not so that it puddles. In a week report back. Then a good weed and feed.
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