Grass over grass & weeds

[Marley]

Hi,

 

My garden was on a pretty extreme slope so I recently levelled it out (as shown below). 
 

My plan is to now raise the level by a few inches using top soil & the roll grass over the top of that.

 

A few weeds are springing up across the current soil and there are also a few grass patches that were already fairly level so I’ve left them.

 

Am I better to put down a weed membrane then 5-6 inches of top soil to minimise the risk of the weeds coming through to the new grass?

 

Any recommendations on how to proceed are greatly appreciated!

 

Cheers,

Ian

[SteamyTea]

There will be weed seeds in the new top soil, and some will blow in as the grass is growing.

Also, if you put a weed control comer down, you cannot easily plants some early flowering bulbs.

[Marley]

Thanks Steamy.

 

So you would just add a bit of top soil, lay the grass and pull out any weeds that grow through (if / when it happens)?

[Thedreamer]

What about a load of cardboard and then top soil on top.

 

 

 

[Makeitstop]

Are you turfing it?

 

[Makeitstop]

I'm assuming you will be, as you mention "rolling it out".

 

Whack it down, keep it really well watered and let it take over a few weeks.

 

After that, and, if any weeds come through it, you can use a spot weed spray like weedol or resolva. It'll knock weeds back but won't damage grass.

[Marley]

1 hour ago, Makeitstop said:

I'm assuming you will be, as you mention "rolling it out".

 

Whack it down, keep it really well watered and let it take over a few weeks.

 

After that, and, if any weeds come through it, you can use a spot weed spray like weedol or resolva. It'll knock weeds back but won't damage grass.

Thanks! Will give it a go.

 

Cheers,

Ian

[saveasteading]

4 hours ago, Marley said:

put down a weed membrane then 5-6 inches of top soil

No.

 

All the above advice agreed.

 

Weed membrane is a plastic sheet that will be in the ground forever. its purpose is for deiveways where nothing should grow, or for the lkes of rockeries where you can cut odd holes for plants.

 

Carboard will do the same and then rot away as compost.

 

OR I think it is normal to rotovate the ground, so some roots will be killed off, then most weeds will be kept down by mowing, and some need spot weedkiller or patient weeding.

[TonyT]

You can add sand to the top soil to improve drainage….

[tonyshouse]

For me minimal topsoil, compacted and then lightly raked to form a tilth, then grass seed, 1/3oz per m2 , once 50mm high roll it, mowing regularly will kill most weeds, prick out any big ones by hand, once established lawn will be lovely, broadleaf chemical possible in the autumn, I avoid ryegrass mixes. 

[PeterW]

Sorry but as the one dissenting voice here, but I would spray the lot off with glyphosate (RoundUp, Gallup360 etc) and then top soil over the lot when it’s died back and then seed or turf. 
 

Anything else you’re just asking for it to come through. 

[Temp]

 

 

3 hours ago, PeterW said:

Sorry but as the one dissenting voice here, but I would spray the lot off with glyphosate (RoundUp, Gallup360 etc) and then top soil over the lot when it’s died back and then seed or turf. 
 

Anything else you’re just asking for it to come through. 

 

+1

 

But don't go too stingy on the topsoil.

 

If you turf make sure you have adequate water pressure for multiple sprinklers. Ideally you want someone home in daytime to move them around and keep it damp for two weeks or so. On a windy sunny day turf can shrink in an hour leaving big gaps unless kept damp. 

 

If any weeds come through use a weed killer that doesn't affect grass like Weedol or for large areas Depitox probably works out cheaper.

[Hastings]

I would ignore all the advice given above. No membrane, no added top soil, no poisons, just mow (not too short). You end up with a mix of plant species, many of which will flower and feed bees and insects, instead of a lifeless, toxic, boring monoculture that looks like plastic and will drain your pocket and your time keeping it that way.

 

Peace, not war (with nature).

 

 

[joe90]

1 hour ago, Hastings said:

I would ignore all the advice given above.

Well it depends on what you want, re wilding is becoming popular now but it’s not everyone’s cup of tea. I have a spotless lawn (mostly) but I have areas of long grass with all sorts growing.

[Thorfun]

put the long wildflower grasses on the flat roof and also have a lovely manicured lawn (tbc) as well. 😉 

 

[saveasteading]

12 hours ago, Thorfun said:

put the long wildflower grasses on the flat roof

After checking the weight and the strength of the roof, and also putting down a specific root-proof  membrane on the roof.   Or don't.

 A suitable surface of earth will add about 40kg/m2 to the roof weight, and then it gets wet.  Few roofs are designed for this weight.

[Thorfun]

6 hours ago, saveasteading said:

After checking the weight and the strength of the roof, and also putting down a specific root-proof  membrane on the roof.   Or don't.

 A suitable surface of earth will add about 40kg/m2 to the roof weight, and then it gets wet.  Few roofs are designed for this weight.

Of course, I should’ve mentioned that our flat roofs were designed to take the green roof weight. 

[saveasteading]

11 hours ago, Thorfun said:

our flat roofs were designed to take the green roof weight

You'd better put some green stuff on it then.

 

I am not against green roofs, but they cannot usually be justified on 'carbon' alone as they require the extra material in the roof, and sometimes walls and foundations too. plus the membranes.

 

For attracting insects and birds ok,  and better to look at than a felt roof.

 

What I don't approve of is an automatic tick for being 'green' if it hasn't been thought through. 

Importing  ready grown sedums in plastic trays and plonking them on a roof doesn't do much for the environment in my opinion.

But I could be wrong.

 

For an admittedly large building, I calculated the pros and cons of a green roof pre-planning. 

It added a lot to the structure and founds. On carbon it would never have paid back the input. Also it would have prevented light rain from reaching the rainwater harvester.

That pic above is clever, in avoiding growth at the edges.

 

Do keep us informed though. the choices, the logic and the practice.

[Thorfun]

23 minutes ago, saveasteading said:

You'd better put some green stuff on it then.

 

I am not against green roofs, but they cannot usually be justified on 'carbon' alone as they require the extra material in the roof, and sometimes walls and foundations too. plus the membranes.

 

For attracting insects and birds ok,  and better to look at than a felt roof.

 

What I don't approve of is an automatic tick for being 'green' if it hasn't been thought through. 

Importing  ready grown sedums in plastic trays and plonking them on a roof doesn't do much for the environment in my opinion.

But I could be wrong.

 

For an admittedly large building, I calculated the pros and cons of a green roof pre-planning. 

It added a lot to the structure and founds. On carbon it would never have paid back the input. Also it would have prevented light rain from reaching the rainwater harvester.

That pic above is clever, in avoiding growth at the edges.

 

Do keep us informed though. the choices, the logic and the practice.

for us it was a decision on aesthetics. we have 2 flat roofs, one joining the main house with the garage and is our utility room which we have a sedum roof. the other is an 'umbilical' from the main house and is our garden room. this flat roof has the wildflower meadow on it as is overlooked by our bedroom and balcony. so we thought that it'd be lovely to look out from the windows in the house and from our balcony on to a lovely green grassed roof rather than the drab grey of a single-ply membrane. 

 

hopefully the bees will be attracted to the wildflower roof but as we live surrounded by woodland the choice was not based on any carbon or nature requirements or to tick 'green' boxes or anything like that. I'm afraid we are simply shallow and was going on looks. any other benefits are a bonus. 😉 

 

we have a large main pitched roof that will be used for RWH but we also have a constant flow of water from the ground around the basement into our sump so we're planning on running that into the RWH tank as it means we will get water even in a period of no rain. the green roofs will run off to a soakaway so as to not contaminate the RWH.

 

the below photo shows the green roofs and how they fit in to the design of the house.

 

 

the pebble surround is actually a requirement for the green roof according to the roofers that fitted them. even if he's talking b*****ks we really like the edging.

 

we have had to have the hose up there recently though as we hadn't had rain for many weeks and it was really drying out. but with the recent rain the wildflower roof has really started to flourish and it is a wonderful sight to see from our bedroom and the grasses and flowers are now high enough that we can see them from ground level as well.

[saveasteading]

Excellent. Yes that will look good from widows above.

The gravel is not 'a requirement' by any rules I know but is a good solution to potential issues that are not always dealt with.

 

If plants die or trees sprout*/ birds die on the roof, have you got safe access?

*Very likely with woods around).

 

I would have thought that water from the green roof could be cleaner than direct runoff from the main roof and gutters.  If you looked in a gutter you wouldn't drink the water, but the green roof is filtering any 'deposits'. Only guessing though.

 

[Thorfun]

17 minutes ago, saveasteading said:

Excellent. Yes that will look good from widows above.

The gravel is not 'a requirement' by any rules I know but is a good solution to potential issues that are not always dealt with.

 

If plants die or trees sprout*/ birds die on the roof, have you got safe access?

*Very likely with woods around).

 

I would have thought that water from the green roof could be cleaner than direct runoff from the main roof and gutters.  If you looked in a gutter you wouldn't drink the water, but the green roof is filtering any 'deposits'. Only guessing though.

 

they're both single storey so a small ladder will allow us access to the sedum roof and we can climb over the balcony railings to get to the wildflower roof so no issues with access.

 

RWH company said to keep the green roof and ACOs separate from rainwater and not to divert it to the tank. I'm no expert so I can only go on what I've been told by the companies that 'should' know.

[Roundtuit]

On 15/05/2022 at 09:07, Hastings said:

I would ignore all the advice given above. No membrane, no added top soil, no poisons, just mow (not too short). You end up with a mix of plant species, many of which will flower and feed bees and insects, instead of a lifeless, toxic, boring monoculture that looks like plastic and will drain your pocket and your time keeping it that way.

 

Peace, not war (with nature).

 

 

Yeah, great.  The kids love rolling around in thistles and nettles... 

I think the OP was after a lawn, not a nature reserve.

[Hastings]

Nettles and most thistles don't survive regular mowing and you can hand remove any that try. But it can take a while so you need patience.

16 hours ago, Roundtuit said:

Yeah, great.  The kids love rolling around in thistles and nettles... 

 

Edited May 17, 2022 by Hastings