Lawn drainage solution?

bastathecat

Hi,

I'm looking for a bit of help in deciding what to do about the drainage issue in my garden.  We moved into a new house over the winter and quickly realised that there are significant issues with drainage in the back garden, particularly the lawn.  It is quite a large lawn (approx. 60 feet by 60 feet) and is basically solid clay.  The previous owners of the house had a French drain system installed at some point in the past (probably about 30 years ago I expect) but this seems to be doing little to improve the situation.  The lawn was squelchy all through the winter and is only now (mid April) beginning to dry out.  Even today it is a bit boggy in places even though we have had no rain for 10 days.  There is lots of moss and weeds but even after scarifying the grass doesn't seem to want to grow.

I've sought the advice of a local landscape gardener who advertises drainage services and he has suggested the radical solution of:

1. digging up the top layer of clay from the whole lawn

2. building three new French drain channels down the garden leading to soakaways beyond the lawn

3.  laying a six inch layer of stone chippings on the whole of the excavated lawn, covered with about 4 inches of new, good quality topsoil and then turf on top.

This is obviously going to be an expensive option but we are keen to get it right so that both we and out kids can enjoy the garden fully.  So my questions are:

1.  is this likely to work effectively?

2.  is 4 inches of soil on top of gravel sufficient or will this actually be too effective and lead to the lawn drying out excessively in the summer?

3.  any other problems that anyone can see with this solution?

Thanks for any advice you can offer!

Dan Almond

Good afternoon,

Firstly, i was in a similar position a couple of years ago, so i talk from my experience (there is a thread on here if you can find it). I moved into a new build; garden was very bland; effectively grass on soil with a high clay content; squelchy when wet. I made a start from late October through winter.

1. Removed all existing turf; opened up soil; removed large lumps of clay.
2. Double dug soil conditioned in. Unsure of quantity, but LOTS.
3. Incorporated LOTS of rotten manure into the soil (handy as i had horse paddocks at the end of the garden.
4. Left over winter to February to allow frost action on the clay.
5. I used Everedge to restrain what would be the new lawn, and imported several tonnes of rootzone (50:50 i believe), which provided a good 100 mm depth ready for new turf.
6. Laid new turf in March.

I had no scope to lay a drainage system as i had nowhere for water to discharge. Couldn't incorporate a soakaway given sloping towards the house and i doubt the water would percolate through the clay anyway.

The above didn't resolve fully, but it did help. Other lawns would puddle up after heavy rainfall, where as mine wouldn't- it did feel squelchy however. Back breaking work, but worth it if you plan on staying. I have since moved house to a place on chalk, and amazed as to how quickly the water drains away!

I think you have to work with it, rather than against!

Dovefromabove

Is this the thread you're referring to John? http://www.gardenersworld.com/forum/problem-solving/preparing-for-new-lawn-in-spring/560711.html 

bastathecat

Thanks for the replies - it was interesting to read your experiences John.

We are relatively lucky in that our garden slopes gently away from the house and there is a patch of woodland beyond the garden, so hopefully some form of drainage system should be possible.

Does anyone have any experience of using a layer of gravel under topsoil/turf to aid lawn drainage?  It would be interesting to hear any experiences of how effective this is.

Thanks again!