Using tarpaulin to kill grass

pjwizon

I'm planning to have a mini wild flower 'meadow' at the bottom of my garden. The ground is spectacularly bad (it's just stones, with about a one inch layer of poor sandy soil). The grass doesn't grow in it at all well - it's thin, parched, and reaches only 3 or 4 inches tall if left uncut for months. 

To sow/plant wild flowers I need to kill the grass and leaving a sheet of tarpaulin over it for a couple of months seems the best option. However, there are tree roots passing through the grass, so can anyone tell me if tarpaulin will kill the tree as well as the grass? 

Hostafan1

why do you want to kill the grass? "Meadows" have grass in them.

josusa47

No it won't.  The tarpaulin will kill the grass, and other small plants, by excluding light.  Plants absorb light through their leaves, so the trees will be fine.

Fairygirl

Just scarify the grass, so that you have a suitable medium for the  wildflowers. No need to do anything more to the grass 

pjwizon

Fairygirl said:

Just scarify the grass, so that you have a suitable medium for the  wildflowers. No need to do anything more to the grass 

If that will work I'll do it, but as I understand it annuals need a reasonably fertile fine tilth. My garden soil is like a one inch layer of dry dust and is horribly compacted. I suppose I could scarify and break up the soil, and then rake some bought top soil into it. 

Hostafan1

I'd germinate them in trays and let them get a wee bit bigger then plant them into the grass when big enough.

pjwizon

pjwizon said:

Fairygirl said:

Just scarify the grass, so that you have a suitable medium for the  wildflowers. No need to do anything more to the grass 

If that will work I'll do it, but as I understand it annuals need a reasonably fertile fine tilth. My garden soil is like a one inch layer of dry dust and is horribly compacted.

Edit: well, I've just scarified a little of the grass and it is possible to leave about 50% bare soil. The process does leave a lttle tiltn, though it's just a very shallow surface tilth, so to speak. Attempting to decomoact the soil with a garden fork is if limited use as I can getting the fork more than one or two inches into the griund requires a herculean effort. I suppose every little helps though. 

Thanks Fairygirl, you've convinced me this is the way to go.

Loxley

The usual problem with meadows is too rich soil, resulting in grass that outcompetes the wildflowers, so it sounds like you might have more luck than most.

Fairygirl

I'd also do the same as @Hostafan1 suggests though - sow some seed for planting out inspring. That will give you a back up. Some seed sown will inevitably disappear over winter, so a belt and braces approach is ideal.
It's usually a case of trial and error too. Pick seed that suits your conditions. If you can , although it's probably a wee bit late now, take a look at what grows naturally in your area - along verges and lanes if you have any. Do a bit of research into different types of plant. That's what I'm doing just now, as I'm creating a small area of wildflowers, just like you are 
As @WillDB says, soil that's too rich isn't ideal for most wildflowers. 

Dovefromabove

And decide which type of ‘meadow’ you’re going for ... a traditional ‘hay meadow’ has flowering grasses and perennials ... ladysmock, cowslips, clovers, buttercups ... and there are different seed mixes to suit your conditions https://britishwildflowermeadowseeds.co.uk/

or you you can go for a mix containing annuals such as poppies and cornflowers https://www.meadowmania.co.uk/wild-flower-meadow/cornfield-annual-seed.htm which need more bare soil and fertility.  

pjwizon

Dovefromabove said:

And decide which type of ‘meadow’ you’re going for ... a traditional ‘hay meadow’ has flowering grasses and perennials ... ladysmock, cowslips, clovers, buttercups ... and there are different seed mixes to suit your conditions https://britishwildflowermeadowseeds.co.uk/

or you you can go for a mix containing annuals such as poppies and cornflowers https://www.meadowmania.co.uk/wild-flower-meadow/cornfield-annual-seed.htm which need more bare soil and fertility.  

Thanks for that. Given how poor and sandy the soil is I was going to use Emorsgate's meadow mix for sandy soils.

https://wildseed.co.uk/mixtures/view/8

One question I have is this: the existing grass is thin and doesn't grow well. Can I sow a meadow mix of 80/20 grass/flowers into the scarified ground, or does an 80/20 mix demand grass free soil? The advice on the Emorsgate website states a bare soil tilth should be used, but a number of people here are saying different things (I hope they're right).

Another issue is including Yellow Rattle in the mix. If I'm sowing into existing, scarified grass (albeit very, very poor grass), should I include Yellow Rattle to limit the existing grass?

I still come back to the shocking state of my poor soil and disbelief that any wildflower meadow planting could grow in it.