Heavy clay soil, drainage, and trees

AnthonyB

I have heavy clay soil, and the drainage is very poor as a result, despite loads of drains having been put in at the time my house was built a couple of years ago. Water sits for days above the grass (two acres of it) after rain, the grass itself grows very poorly, and having planted loads of trees (literally hundreds, including whips) many of them have died, and the rest are struggling really badly. One tree I dug up after it died (it was in the ground 12 months) was shaped exactly like the way it came out of the pot, and was sitting in literally 4" of water.

I am thinking of putting in a series of additional land drains with smaller finger drains, and connecting them all to the main drains that keep the immediate footprint of the house dry (they do this very effectively). However, I don't know how this will solve my problem with the poor soil. While it should take the water away quicker, will I still have the problem with the trees because the base soil is heavy clay? I know I can get healthier more vigorous grass, but what I really want is trees, and it's killing me not to be able to grow them.

Any help appreciated!!

Thanks..

AnthonyB

woodoo

Have you thought about getting a digger in to chew it all up to about 8inchs to 1 foot. Mix in sand etc.

AnthonyB

woodoo wrote: »

Have you thought about getting a digger in to chew it all up to about 8inchs to 1 foot. Mix in sand etc.

It's been done. We had the place landscaped a couple of years ago after we built the house. Thinking of putting in a load of land drains now. My big fear is we plough more cash into the thing and it still won't let trees thrive in particular.

just do it

http://www.teagasc.ie/publications/2012/1334/Solohead_Open_Day_2012.pdf

Good article in here on land drainage. Mile plough to encourage surface water to drains is probably what you need.

whizbang

http://www.teagasc.ie/publications/view_publication.aspx?PublicationID=1334

bbam

We farm on heavy clay soil so I know your pain.
The drainage will work but the key is the spacing. No more than 2-3 feet between drains will give you a good result.
Don't be thinking your going to have a top notch job. All you can do is make the best of the clay soils.

You mention planting trees from pots, I wouldn't recommend this. Plant bare root and choose only vigerous varieties for poor soil.

AnthonyB

Thanks all for advice - though I couldn't see a whole lot in that teagasc paper on land drainage..just someone complaining about poor drainage on page 27...

I've just walked it again with a friend of mine who's done a bit of work on this, and really we have very poor topsoil in places, and mostly it's mixed in with the clay sub soil. Also, when building the house I covered in an open drain (I put in a French drain instead) that ran the length of the site in order to reclaim the 5m of my site that it was taking up - that seemed excessive. In hindsight it may have been foolish.

I think we're going to dig some open trenches to lower the water table. Then, I'm going to dig holes about 1m deep, 5m diameter, and fill them with top soil. I'm going to create mounds with the spoil. I'll put land drains into the bottom of the holes, leading to the trenches. Then I'll fill the holes with top soil, cover the mounds with topsoil, and plant trees in the holes, vigorous shrubs on the mounds. That will get us the wind cover and screening that we want. We may also dig a pond.

Most importantly though we need to recognise the land for what it is, and its shortcomings, and plant accordingly...so no beech wood that wifey had been dreaming of, unfortunately

AnthonyB

Oh, and I did call Teagasc a few weeks ago and asked them if someone could come and look at the land and advise me on drainage before planting...they said they'd get back to me. Then they left a voice mail, and said - with no hint of irony - "we're sorry, but we can't help - it's really not our field!!!"

just do it

Here is the Teagasc booklet I was thinking of. I see my link is broken.

I've never planted trees but what you describe sounds like it should do the trick, along with choosing suitable trees of course;). But you've that covered. Have a look around your locality to see what is growing in similar terrain.

Best of luck!

AnthonyB

just do it wrote: »

Here is the Teagasc booklet I was thinking of. I see my link is broken.

I've never planted trees but what you describe sounds like it should do the trick, along with choosing suitable trees of course;). But you've that covered. Have a look around your locality to see what is growing in similar terrain.

Best of luck!

It's funny...there are half a dozen great big 50 foot beech trees right on the corner of our site. I think we completely f%*^ed up the land when we landscaped and all that. It would probably have been fine had we decided to take the spoil from the build off site, but that would have cost us 10k. I think I'd pay that now!! (Did I mention we "pulled back" all the top soil and then buried the spoil from the build? I should probably have mentioned it if I didn't...)

Well, we'll live and learn.

AnthonyB

Another issue has come up - given the amount of digging and mounding and all that stuff we did on the site with the house, we may have shifted the water table around a bit. That's according to one sage local anyway...and that perhaps a hydrologist could do some tests. We may consider that... more to chew over!!