Waterlogged soil and lawn

Hi All,

After some much needed help here. I have moved into my house 5 years and I am finally getting round to trying to get my garden sorted out.

This has been mostly prompted by my fence posts rotting underneath the ground due to how wet the garden is as my house is at the bottom of two hills.

My garden is roughly 1/2 acre in size. I previously had put in a drainage channel and while installing it I discovered that my garden is filled with hardcore 1.5 foot below the top of the garden. The drainage channel did not work very well at all. The drainage channel had a sufficient fall and had drainage gravel in along with the pipe.

Last weekend I went out to dig a small hole in my garden to test how far down I would have to go to get to the hardcore for putting in the founds for a garage. The lawn was soaking wet and when I put the spade into the ground I could hear air rushing in. This has made me wonder is the main issue with my garden not draining to do with the topsoil being too heavy and not being sufficiently aerated? I am wondering if that is possible?

I am replacing my fence with hedging and planting trees; I have picked plants that will grow in wet ground so I am hoping that this should also aid the drainage.

Any advice will be gladly received

Cheers Keith

 

Almost sounds like a mini version of artesian wells. Solar powered sump might help.

 

That's sounds like an interesting idea. Would make for a cool water feature.

 

Aerating it certainly wouldn't do any harm but if the soil is clay on top of compacted hardcore, you'll forever have problems with saturated soil after periods of rain, especially during the colder months. With it being at the bottom of two hills, it compounds the problem significantly.

Your idea of planting trees is a great idea and would make nice focal points with circular borders and some perennial plants, bulbs, shrubs or whatever takes your fancy. Mowing around objects in the garden isn't ideal, especially if you like a striped lawn, but with a bit of practice, you'll pick it up.

Some trees that like water are dogwood (fanstastic red stems in winter), river birch, alders, poplars and weeping willows.

Poplars grow to incredible heights and willows are beautiful but can grow huge too, which can create shade issues. Also, willows tend to make more of a mess than other trees as their leaves are so small and difficult to rake up, plus the small long leave stems that fall clog up leaf vacuums. But they are so beautiful this can be forgiven, at least in your own garden .

 

The good thing in terms of leaves is that we are far enough from neighbours for it not to be an issue.

Going to have to find away around the clay soil long term. Not too fussed on having striped lawn so it's not too bad having to cut around trees.

 

As an update to this I had dug a small hole about 3' x 3' and 1.5' deep. I dug this hole to get an idea of how deep I would have to dig to get to the hardcore for founds for a garage. When I dug out the hole the soil was wet but when I dug down there was no water lying. I got down to where the hardcore is. Now the hole has filled with water. I know it rained a bit last week but from memory it hasn't rained for a few days now. So the water is not draining. I am wondering what is my best way of sorting this out long term?

Cheers Keith

 

I'd normally say incorporate as much organic material into the clay as possible, but if it's a foot and a half thick that'd be a hell of a job.

If you can get hold of some sort of corer or post holer, then you could drill several holes and fill them with gravel to help drain the clay.

 

Might sound crazy but I'm considering getting the garden ploughed. Then add organic material and gravel and sand. Then repeat with a rotivator. Don't know if that is likely to help?

 

I'd have a word with the builders that built your house on a landfill site first

 

The builder added the hardcore. I think he was trying to use it to aid the drainage.

 

More likely saving on skip costs

 

Normally I'd agree but from what I've been told by the local farmers the builder brought the hardcore from a house someone else was taking down.

My lawn is mostly moss due to the wetness. It also has rushes in the garden.

 

Plouging sounds like a drastic measure and would unearth a huge amount of hardcore (and bury some again), which would be a problem when rotorvating. Hopefully there aren't any building foundations down there! May be worth asking around your neighbourhood if there were any former buidlings on the site.

It may be worth scraping up a few areas of turf (to save for laying again later) at various points in the garden and do a bit of digging around to see how compacted and deep the hardcore layer is. And beyond that, dig some more. You may even find there is a high water table underneath.

 

I've asked already there never was a house on my site before. So it shouldn't be founds.

Some of the garden is draining and dry and as I'm digging up for a hedge at the moment I can see there is plenty of sand in the dry areas.

I decided today to perform a mason jar soil test on one of the wet areas. I can see very little sand and almost all clay. I think that might be my issue. I need to figure out the best way to add sand to the soil I think. Here is the results of the soil test with and without flash.

 

What sort of sand should I add? Is it just builders sand?

Cheers Keith