Nightmare lawn

[cwhaley]

Hoping for some advice on what has become a nightmare lawn.

Last summer my lawn - although uneven - was something I was fairly proud of. I'd fertilised it, laid a few new rolls of turf to the left and got rid of the moss and weeds. It looked like this:



This snow and rain this year though has taken a very bad toll. The new turf on the left was given to me free and I clearly didn't raise that side high enough when laying it. We also have soil which is full of clay and this obviously hinders drainage. As well as the slope towards the left, there are several pits in it about 3 or 4 inches deep (around the yellow areas). It now looks like this (excuse the mess, the garden is this spring's job):



So how can I level the lawn out? Can I cut out the dipped sections, fill will soil and then re-cover with turf? As for the new section which has flooded on the left, I will re-lay this - just don't want to be re-doing the whole lawn as I know it can look good!

Thank you.

 

[TicTac]

You may find you can still lift the turfs that have sunk, add some more soil, and then rebed them. And if you have to do this, then it might be a good idea to put in a french drain at the same time.

Take a look at the paving expert, but beware of the caveat at the bottom of the page.

 

[cwhaley]

Thanks for this - that website is a great resourse. The piping seems to be quite cheap which has surprised me if I'm honest. Once I've lifted the sunken areas in April-time I'll look at what I'd need to do to run a few trenches down the lawn. I had used a fork earlier in the year but I think this just compacted the soil even more.

The soil is so full of clay in areas it's possible to re-create that scene from Ghost.

 

[TicTac]

Clay keeps the moisture in the soil, and if the area doesn't dry out, then that helps moss grow. Putting holes in the ground is supposed to help aerate the soil to reduce it, so shouldn't have caused a problem. Don't wish to sound negative, but with that much clay, would it be sensible to either rotovate the soil, or dig in some roughage to help the clay areas.

We are going to get hotter summers, and may even get colder winters, so getting the ground done properly may help the grass survive better, than doing remedial pipe work that is remedial, rather than getting to the heart of the problem.

 

[cwhaley]

I agree - we had nearly a foot of snow a couple of weeks ago which lingered for a week keeping the ground very wet as it melted. Subsequent rain has also topped up the water levels. I think using the fork just compacted the soil around it - I've been told I should have used one with hollow tubes to actually remove soil.

I'm going to raise the sunken areas as you suggest, bring the left-hand side up to level, use an aerator and fill the holes with fine sand. I'll also look at French drains.

If the same happens next year then digging in some better soil and raising the lawn up may be the only option - I dread the thought of the work though! Although flood defenses put up 70 years ago have stopped flooding in the area, the ground can get saturated in heavy rain. After all we are on a flood plain within 2 miles of 4 rivers (Soar, Derwent, Erewash and Trent).

 

[StephenOak]

I've been told I should have used one with hollow tubes to actually remove soil.

The one time I used a hollow-tine aerator (c. 5 years ago) it made a huge difference.

In winter after rain the lawn was a bit soggy for a day or so (depending upon how heavy the rain was) apart form the bit at the RH side that is lower and would have visible water on the surface. Our soil is okay and the garden is on the side of a valley (house at the top) so overall drainage is not a problem. So I decided it must be compaction.

I used a hollow-tine aerator over the whole lawn, with the holes were in a square grid, lines of holes were as far apart as the gaps between the tines. From a lawn just under 100 sq. m I got out 40L of plugs of soil. After doing this I brushed in some (3? 4? bags) of horticultural sand*.

That was in the November and over the following winters we have never seen visible water on the RH side and the lawn is not soggy after rain.

I tried a couple of months earlier and could not get the aerator more than an inch or into the surface. After very heavy rain I tried again and I could get the aerator in okay. I did it over three days and the lawn dried out and became harder to penetrate so I put a sprinkler on each area before I worked on it. Even so it was incredibly hard work. If I do it again I will be very tempted to use a powered version.

* AFAIUI, horticultural sand is just sand that has a low lime content and has been washed to remove most of the salt. Lawn sand is this mixed with an iron compound which acts as a moss-killer, here the sand is a bulking agent to make it easier for you to spread the moss-killer at a low dose.

 

[cwhaley]

That's a really helpful post -- thank you. Your old lawn sounds similar to mine now; at the moment I hate going down the garden to the shed as I want to avoid a Glastonbury style lawn. In fact it's so bad my feet make clear impressions into the lawn and the grass squelches as you walk on it. Granted there's a lot of water around at the moment and it does improve after a few days of dry weather.

As I've said I'll level it out first to get a better presentation and try a hollow-tine aerator on it this spring. I'm hoping to borrow one off next door's gardener as I can't seem to find a second-hand one anywhere. Really positive to hear you had good results with one anyway. I don't mind the hard work if it's free! Also, thanks for the heads up on horticultural sand - it sounds a better solution for a lawn than ordinary fine building sand.

I know lawns can take a lot, but it was hard work getting rid of the weeds/moss and by August my vintage Atco was leaving lovely lines on the lawn. Don't want it all to be un-done!

 

[StephenOak]

Mine was never as bad as the far LH corner of yours, my underlying drainage is good so once water got through the compacted layer it went away well.

at the moment I hate going down the garden to the shed as I want to avoid a Glastonbury style lawn.

Would a pair of spiked 'overshoes'
https://www.amazon.co.uk/Greenkey-Garden-and-Home-Ltd/dp/B001NUYLN8/
help at all? Being bigger they will spread the load and might do some good at the same time.

and try a hollow-tine aerator on it this spring. I'm hoping to borrow one off next door's gardener as I can't seem to find a second-hand one anywhere.

My recollection is that aerating is best done in the autumn but I cannot remember why. There may be something on Lawnsmith.

I inherited an aerator with the house but they are not that expensive, c.£15
https://www.amazon.co.uk/Oypla-Hollow-Aerator-Outdoor-Garden/dp/B071W78311/

I don't mind the hard work if it's free!

Say that again after you have done the lawn! Putting it in is not too bad (you can use your weight) but pulling it out really kills the arms & back.

I did look to see if I could find a better solution and I did
https://www.amazon.co.uk/Step-Tilt-Lawn-Aerator-Model/dp/B00BXL6HV6
but it is American and they don't ship to the UK.

Also, thanks for the heads up on horticultural sand - it sounds a better solution for a lawn than ordinary fine building sand.

I have seen people say that they use building sand with no problem. I can't remember but I probably paid c. £5 a bag and I thought that was worth it to be a bit safer.

 

[TicTac]

If you're on a flood plain CW, then you may be faceing an uphill battle, as the water level in the ground may be having a certain affect on the lawn. I hadn't heard about the iron in lawn sand, but you can get washed sand for plastering and for block laying as well. As to the squelching going down to the shed, sounds as though some blocks in the lawn might be a good idea.

Keep us updated on this one.

 

[cwhaley]

Thanks both. TicTac - yes on a flood plain but I think the real problem is the layer of clay acting like a skin on top of the earth. I forgot to mention, but below the clay/soil (around a foot down) is a layer of sand so it's just about getting through the clay I think. British Gypsum operate a quarry (or used to) 2 miles away near the A50 purely because of the sand found easily around here.

Stephen - thanks for the links I'll have a look when I'm back home. As long as I can get the water to drain into that layer of sand I think I'll be okay. If I level the area on the left that will raise the lawn 6" that side so I shouldn't see the pooling water. After that I'll go with the best way I can find to aerate it. I've since found out the local wood yard sell sand and do the horticultural stuff at £4.50 a bag so I'll grab a couple.

I'll update this thread next month when I start work. Weather dependent of course as we're forecast 8 degrees today and -2 on Saturday...!

 

[StephenOak]

If I level the area on the left that will raise the lawn 6" that side so I shouldn't see the pooling water.

I'm not an expert and I have never had to deal with this myself, but just raising that area on top of the existing clay sounds like, rather than draining away, the water will just fill up that top 6" until it has reached capacity and then start pooling on the surface.

What I think you need to do is to make that clay layer more permeable. So when the turfs have been removed did a load of sand / organic matter into the clay.

Maybe you have that in mind and I did not pick it up. I just wanted to be sure.

 

[cwhaley]

I'm not an expert and I have never had to deal with this myself, but just raising that area on top of the existing clay sounds like, rather than draining away, the water will just fill up that top 6" until it has reached capacity and then start pooling on the surface.

What I think you need to do is to make that clay layer more permeable. So when the turfs have been removed did a load of sand / organic matter into the clay.

Maybe you have that in mind and I did not pick it up. I just wanted to be sure.

Sorry yes that is part of the plan.

As I say, there is sand below the clay - it's the same at the house I grew up in about 1/2 a mile away. If I can allow water to pass through the clay and into the sand and then raise with top soil I can't imagine I'd see pooling water again.