Seeding a new lawn

I have a friend that's asked me to help get his back lawn sorted in a brand new house he's bought. I think I know what I'm doing but wanted to check with you guys to see if you agree/suggest anything different.

He's bought a new house where the soil is quite tough and the house builders left a lot of rubble and waste in the garden. He's spent ages clearing out the rubble and waste in order to get it ready to seed. The area is square and on one level. I would say it's a good 125-150m2 that he's got. In places the ground isn't very level.

1. My suggestion is to make sure it's clear of as much rubble, rubbish and weed as possible.
2. Dampen the ground.
3. Evenly sow a good hard wearing grass seed (I've suggested - 50% Dwarf Perennial Ryegrass (Fine leaved & hard-wearing), 50% Strong Creeping Red Fescue.)
4. Put down some pegs and string to see where the low spots are.
5. Cover the whole lot with a couple of tonne of top soil
6. Build up the areas that are low with additional top soil
7. Use a long wooden batten attached to a rake to "push" the soil into the hollows and get it level
8. Walk on it to compact the top soil
9. Add a summer feed
10. Water the area with a sprinkler every evening for several weeks until it takes

My guess is that this should cost a few hundred pounds and days hard work?

What do you think?

 

Put the topsoil on first. Gives the seed something to work with. Next summer it'll need more topsoil for top-dressing to smooth out the inevitable hollows, but that's a job for another day.

You definitely don't want summer fertiliser. That builds leaves. For helping the grass to build roots, you want autumn fertiliser. And we're well into September now, so we're past summer anyway.

When the soil is level, rake it to give a good tilth. Sow the seed, and rake it in carefully to cover it, or sprinkle extra topsoil over if you've got some spare. Be extra careful not to move the soil and seed around too much, otherwise you'll get bare patches.

Your feet are going to mess up the carefully prepared surface of the soil. When you seed the lawn, get two ladder sections and use them as walking boards. Each ladder is about a foot wide, so start with one ladder section 2 foot from an edge of the lawn-to-be, and the other section a foot behind that. If you're seeding by hand, a 2 foot section is about all you can do accurately anyway. So seed and rake the 2 foot section of lawn in front of the ladder, then move the front ladder section to the back. Now you have another 2 foot section to do, and you can rake over the dents left by the ladder too. Keep going until you've covered the whole lawn - and don't put a foot on the seeded area again until there's grass on it! The result should be a perfectly prepared soil structure for the seed to root into, without footprints messing up your nice surface.

For buying seed, I totally recommend GSS Direct. I reseeded my front lawn this year, and it's come up a treat. Link below for some pictures. Their choice of seed lets you tailor it for your needs better than any garden centre box of seed too.

Buying grass seed online - a recommendation

 

Oh, and when you level it, level it with a gentle gradient towards where you want it to drain. 0.5-1cm fall per metre is about right. Use a spirit level to set up the tops of the pegs level, at metre intervals, and then mark off down each peg where you want the soil to come to. If you don't put a gradient on it, any slight hollow becomes a puddle in winter.

 

Perfect, thanks for your reply Graham.

I've taken your suggestions and made a plan which is hopefully improved. A local lawn expert said that the area my friend lives in is very "solid" and "clay like" soil (I agree as I've sampled that myself). He has suggested that aerating the soil that's already there (mechanically or manually) would really help. Once the whole area has been forked he suggested using a 70:30 top dressing to fill the holes that have been made and add a layer of the top dressing over the whole lot at a rate of 5-8 kilos per m2. This will help prepare the surface really well and improve the drainage of the soil as it'll help break down the tough starting surface. We'll be using garden forks to aerate it and I'll make sure that the fork gets a good wiggle to put in some big air pockets so they fill with the top dressing - I'm guessing this is the point.

The whole area is about 120 m2 so I've got the following arriving tomorrow:

• 1 x tonne of 70:30 top dressing (keeping some of this back for next season to level it out as you mentioned wouldn't be a bad thing would it?)
• 2 x tonne of top soil

The plan is to get a layer of top soil on after the top dressing, seed it and then apply the remaining top soil over the seed.

How does this sound?

I've also switched the feed to an autumn 4-12-12 - is this better?

I've not heard about not walking on the area once it's been prepared. I was under the impression that after the final layer of top soil was down then I could walk on it to flatten it out with a large piece of wood attached to the back of a rake and then watering every evening for a week or two.

I don't have access to ladders that's all

Good idea about the gradient, I agree. To the eyes that wont be noticeable but it will help with drainage and water run off for sure. Any tips with the pegs and level would be great. I'm guessing you mean to cut some some small pegs that stand up 10cm (or so) tall. Then get the tops all level using a spirit level/string. Finally mark them with a marker pen where the desired level will be by measuring from the top of each peg downwards to achieve the 0.5 - 1cm fall per metre? If I find that the overall fall is naturally running away from the house at a 1cm or greater fall then this would be fine to go along with? Basically, don't have it totally level as it will inevitable puddle where there's any slight hollows?

 

Why do you require a feed? There’s no need if you are preparing the site and the chances are as the seed germinates the nitrogen will have a negative effect. There’s enough natural nutrients already to give the turf a good start.
There’s also some confusion about dressing and top soil.
I’m good at turf but even I can’t get a a dead accurate fall off as soil settles which is why the preparation is important.
If the ground is solid a slope angle is pointless, you need to insure it will drain and if solid a fork which will compact the hole is pointless.
Take a step back and have a think about the situation before jumping in. You don’t want the end result poor and down the line you have issues.

 

The only reason for doing it tomorrow is due to work and family not allowing any other time. Fitting in time to a job like this is not easy.

Ok so no feed, that makes sense. Perhaps a feed at the end of October/early November would help?

This will be from seed and not turf as you’ve mentioned.

Any help and advice would be a appreciate please. Thanks.

 

If he's cleared out a load of debris, he's already dug over the site well enough. You don't need to mess about with spiking it and stuff. (And for the record, don't wiggle the fork too much to create "air pockets" - that'll just create gaps which need to settle again.) The main worry is soil compaction, and your friend has sorted that.

Level the clayey soil fairly well before you drop anything else on top. I'm even more in favour of a slight slope on soil which might not drain so freely, just to help a bit.

You can stomp over the lawn to flatten down the top soil, but the point is that you then rake it over, sprinkle seed, and then gently cover the seed. If you walk on that, you're going to bugger up all that carefully prepared soil structure and seeding. If you don't have walking boards, just keep working backwards and rake over your footprints before you seed the next bit.

Agreed with Liz that you probably don't need fertilizer. Stash it for next year. And as Liz says, top soil and top dressing aren't the same stuff.

 

So, he dug out the rubble a few weeks ago although I think a lot of it was just resting on top. The area has now settled and it quite compact. The local lawn specialist guy was the one who suggested using the 70:30 top dressing (which I’ve ordered and it’s arrived) with the idea of getting 5-8 kilos on per m2 as the soil he’s got is very solid. He said that most builders would just turf it but by doing that it’ll look good initially but the better preparation that done the better longer lasting it’ll be. So he suggested aeration first and then spreading the 70:30 so it goes into the holes and levels out the area. The reason for it is to get some uneven particles (sand) into the soil so it’s there to break it down a little and give a better starting surface to work from.

Then a layer of top soil, seed and then top soil again as you’ve suggested. I see what you mean by not walking on it. You’re suggesting that the grass see will take better of the top soil is loose/raked and then the final layer of top soil to cover it is sprinkled on too?

If I don’t use the 1 tonne bag of top dressing (which wasn’t cheap) I don’t know what I’m going to do with it. I’ll be trying to keep some back to used next year to level out any dips in the lawn too.

Yes, the fertiliser can be kept for future use.

 

Have you bought extra topsoil *and* top dressing?

Whichever you've got, if it's clay soil then a bit of something more free-draining on top will help the seed get started better. If it's top dressing then keep some back for next year. Lawns always settle, and however much you try to get the soil level, it's never perfect. Top dressing next year will sort that out.

Dense soil isn't really a problem for soil under lawns. The only problem is if it's formed a layer of hard pan which water won't drain through. If your friend has dug out rubble though, he's probably broken up any hard pan layer. If it did need that sorting though, you'd need a week of hard graft or a day with a rotovator, and then leave it to settle for a couple of weeks, and then we're getting a bit too late for the grass to do anything before winter. Have a word with your friend, but chances are you're ok as you are.

Yes, seed likes a fine grained soil to grow in. (The word is "tilth".) If you hit Google and YouTube for advice on seeding a lawn, you'll find plenty of stuff out there.

 

Perfect, thanks for your help guys.

Yes, bought the following...

• 1 x tonne 70:30 top dressing
• 2 x tonne of top soil

The idea was to spike with holes and fill them up with the top dressing and apply at 5-8 kilos all over and keep 1/4 of the tonne bag for next year levelling.

After this to apply a load of the top soil (and walking on it is fine at this point). Finally rake it to create the tilth and the sow the seed onto it followed by covering the whole lot with a final layer of top soil and then watering.

How does this sound?

 

Just go easy covering the seed with top soil. The seed really should just be raked in rather than buried under soil.

 

Got you. So you pretty much suggest getting 80% of the top soil down first. Giving it a little rake, sow the seed and the sprinkle the remaining top soil on top to create a fine covering up hide it from the birds?

Does the ground prep sound ok with the holes and top dressing approach? This was down to a local lawn guy saying that this will help improve the soil/clay that’s there already.

 

If you want to follow that guy's instructions, you really need a hollow tube aerator to remove soil from the little holes. As Liz said, if you just use a fork, you're making a hole by compacting the soil sideways - and if you're trying to improve compaction then that's not exactly going to help.

Honestly, if your friend has already dug it over a bit, you may not really need this. Still, it can't hurt.

The fact it's a new house makes me less worried, because regardless of how the soil has been compacted during building, it was probably a farm until recently, so it's probably basically OK. I've had to do the same as you in a garden of an ex-council house where nothing much had been dug over since it was built in the 60s, and that soil was *solid* and completely lacking in any goodness, and smelt foul with a big layer of hard pan. I don't think yours should be that bad.

 

You need the seed covered so it germinates. But not too deep so the shoots can get to daylight as they sprout.

Funnily enough, birds don't eat it. Seed eating birds almost all won't eat from the floor. Funny thing, but you look at the bottom of a bird cage, and they just don't eat what falls out of the feeder. Chickens will, of course, and sometimes pigeons, but that's about it.

The worst thing for messing up a seeded lawn is cats. Dogs too, but you can keep them out more easily. Cats are a bugger though, and the nicely raked soil looks like a perfect litter tray for them. If your friend doesn't have a deep and abiding dislike for stray cats in his garden, like most gardeners, then it's time for him to develop it now.

 

Cool, that makes sense about not forking it. Would you suggest laying a layer of the top dressing as suggested? I’m guessing there will be some gaps and cracks in the surface so some will be lost in the cracks and the rest will form a layer on top. I’m guessing that over time the layer of top dressing will start to sink into the base to help that break down a bit over time?

As I’ve got it and paid quite a lot of money for it I’d quite like to use it.

And of course keep some back for next year once it’s all had the chance to settle to its level.