ᐅ How can I improve clay soil?

Created on: 10 Apr 2024 10:16
F
FrankChief
Hello,

we have a newly built house and are experiencing waterlogging issues in the garden.

There is about 50 cm (20 inches) of topsoil, which already contains some clay, followed by approximately 1.5 m (5 feet) of a thick clay layer.

The clay layer only allows water to pass through very slowly, so the garden remains waterlogged for about 1-2 days. Excess water can drain away through a French drain (soakaway) as long as there is a slope, but the soil also settles unevenly.

However, waterlogging still occurs in the soil itself, especially within the top 40 cm (16 inches), which plants do not tolerate well.

We cannot loosen the clay layer even with a rotary tiller. How can we improve the soil? Would it be sufficient to spread, for example, 10 tons of river sand over approximately 180 m² (1,940 sq ft) and incorporate a soil activator by tilling it in?

What else can we do?

Would it help to plant deep-rooted plants for one year, till the soil again next year, and then finally plant the lawn?
S
Schorsch_baut
17 Apr 2024 13:42
Better to remove the excess now than to have to get rid of overgrown grass later.
Tolentino17 Apr 2024 13:47
This may sound harsh, but with all the questions in this forum, I don’t understand how such an unplanned rush job can happen….

Rent an excavator. Remove about 30cm (12 inches) of mixed topsoil from one half of the area. Then remove the excess clay soil (directly into containers). Do the same on the other half by redistributing the topsoil.

Everything else is nonsense—you just want to finish at some point.
C
chand1986
17 Apr 2024 15:48
Tolentino schrieb:

Rent an excavator. Remove about 30cm (12 inches) of mixed topsoil from one half. Then remove the excess clay (directly into a container). Do the same on the other half by redistributing the topsoil.

This would be the practical approach using heavy machinery.

Based on experience, lupines cause some subsidence in heavy soils, especially since there is sand underneath here.
The downside is, you only find out later if it’s enough. With the excavator, you know immediately.

Why would anyone want to dispose of 180 sqm (about 1,940 sq ft) of turf?
K
kbt09
17 Apr 2024 17:08
However, if the lawn area is higher than the terrace, you should also consider that heavy rain events might flood the terrace, and I am not sure how effective the waterproofing towards the house is.