ᐅ Preventing weed growth on excavated areas

Created on: 5 Jul 2021 10:18
C
Colorblind
Hello everyone.
We are currently planning our outdoor area and are doing as much as possible ourselves.
We have already had the future lawn area excavated, since large trucks cannot easily access the site after the terrace and other surfaces are installed. Early next year, we plan to fill the area with 20 to 30cm (8 to 12 inches) of topsoil once all the paving and other surfaces are completed.

Now we have a serious problem with weeds, especially thistles, and I have been considering covering the excavated area. The question is: Is this effective, and can it help control the weeds well? Would it be better to use an opaque landscaping fabric or a tarp for this purpose?

Thank you very much and best regards 🙂

Baustelle im Freien mit aufgeschütteter Erde, Kieshaufen und Wald am Rand.
M
Myrna_Loy
5 Jul 2021 11:05
With thistles, I would handle it before filling in the area – once the seeds start to disperse, it becomes very difficult to get rid of them.
C
Colorblind
5 Jul 2021 11:08
Thank you so far, I am currently just looking into planning and have found a silo liner that roughly fits the size and is lightproof. I think I will order it and lay it out once the ground has dried a bit.
H
haydee
5 Jul 2021 11:15
I would recommend removing thistle by digging it out.

Use a plastic tarp or herbicide, or mow weeds very short so they don’t go to seed.

Tilling can actually spread some weeds more, such as ground elder.
rick20185 Jul 2021 11:44
It makes sense to apply herbicide after removing the topsoil. You can also sow seeds immediately afterwards. Whether you want to do that is up to you. Alternatively, you can cover the area with a tarp for 1–2 weeks. You will always have some weeds, so frequent mowing and hand weeding are necessary. In the current state, it doesn’t really help because the light-dependent seeds will all be covered later.
M
Myrna_Loy
5 Jul 2021 11:49
rick2018 schrieb:

It makes sense to apply chemicals after the topsoil. You can also sow right away. Whether you want to do that is something you have to decide yourself.
Or just cover with a tarp for 1-2 weeks. You will always have weeds. Regular mowing and hand weeding are necessary.
In the current condition, it doesn’t really help. The light-dependent seeds will all be covered later anyway.

It does help insofar as preventing this year’s seed spread across the property, which could later blow back onto the area. Especially with thistles, it’s important to prevent seed dispersal. I’ve had personal experience with this—the landscaping planner assured us that 30cm (12 inches) of fresh topsoil would be enough to stop the regrowth of unwanted plants. But everything came back anyway.
H
halmi
5 Jul 2021 12:12
However, the material definitely did not sprout through the 30cm (12 inches) but was either in the topsoil or simply ended up there again.