land drains

[tracie]

Dear All,

Happy new year to all allotmenteers. may all your weeds be small ones.

I have just taken over a third half allotment plot and have spent the last few days clearing the terrable mess left by the last tennant.

The soil is heavy clay, one side is ok with a reasonable amount of top soil. The left hand side is a shallow top soil and at about half a spit yellow clay and sodden. We have dug out a ditch of aprox two spits to try and drain the water away.

We are not sure what to do next. Does anybody have any experiance of putting in land drains, any help would be great, or would I be better filling the ditch with shingle to act as a drain. Now is the time to do it since I will make the plot into raised beds.

PLEASE can anybody help.

Thanks

A very muddy Tracie

[peter]

Only observations of farmers and contractors.

Used to be unglazed clay pipes, laid in the bottom of a trench, then covered with about a foot of coarse gravel. A mole (tubular lump on the bottom of a 1/2" X 16" mount) was then used to make side drains, a bit like a kids drawing of a fish skeleton, These could be joined up to a main drain and so on. The lie of the land was used to achieve a fall for the water to run down.
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Nowadays I believe rolls of perforated plastic tube are used.

Provided you have some fall to a ditch or drain you could try the trench and pipe method with gravel on top. Fall can be manufactured by grading your trench, I guess one foot fall over thirty feet. You might be able to get the "proper" modern perforated plastic pipe from a builders or agricutural merchant.

No use you doing it if there is nowhere for it to run though. You would get complaints if you drain your plot into your neighbours.b

[Ian F]

Tracie,

I suspect that you are seeing your plot at it's muddy worst, especially at this time of year, and that there are less drastic options than land drainage that you could attempt first.

I had very badly drained clay soil, and tackled it in two ways.

1) I also put drainage channels in, and part filled them with stone and gravel, to drain the worst of the water away. It was heavy work as I guess you have realised, and can be pricey as well, so I restricted the amount that I did to the very worst areas.

2) I also put in raised beds, and increased the soil level with the addition of course grit and organic matter. This raised the plant roots above the water level, and also deals with your other big problem, which is that clay can be a very cold and unforgiving growing medium even at the best of times.

Although it is a little bit late for this year, do not underestimate the benefit of both double digging and winter digging. I know that there is a bit of a vogue for no-dig, but on soil like yours, you need to incorporate serious quantities of organic matter, and soil dug in the back end of the year will weather down during the winter, and you will get a finer crumb in spring.

Although the amount of work can seem daunting, the good news is that once in good fettle, clay makes an excellent soil.

Happy Allotmenting

[tracie]

Thanks for your replys. I think I might put some gravel in the trench, then use the raised bed method.

My other plot next door, thinking about, it was not quite so bad when I took it on a a couple of years ago. I put in 4 raised beds and loads of manure and the soil is now a lot better. It was a lot of work but well worth it.

Thanks for your help


Tracie

[jane E]

I'm facing exactly the same problem in my garden. We go down a spit to meet the yellow clay. It's very compacted in the first spit with blue clay and a mottling of red. I roughly dug one area and manured it and sowed potatoes. Then the following season my husband made raised beds.We filled them with imported soil, manure and compost. In retrospect I think I would be carefu; about importing soil because of nasties like the NZ flatworm. However they've grown crops very well this year and we don't seem to have had any drainage problems. The next part is more compacted and wet and I'm going to lawn it eventually. I've grown potatoes on it and now I'm going to use some of that perforated pipe and gravel and drain it into the field. It's just a case of completing the rough digging and trenches at the moment and I'm a woman of 56. I use a stainless steel spade and work on a bit at a time and the bits are adding up gradually.So my advice is - have a longterm plan but don't let the entirety overwhelm you. Give yourself shortterm goals.

[oldherbaceous]

Just a little tip for anyone that has to dig any sticky clay, keep a bucket of water near you and dip the spade blade into it after every couple of uses, you won't believe the difference it makes until you have tried it.

Herby's handy tip.

[Johnboy]

Hi OH,
I can tell that you used to dig footings by hand in the past with that tip. Laying land drains by hand we used to use the same method and used a grafter spade which you are no doubt familiar with.
JB.

[Weed]

Thanks for that tip OH...very useful

My plots are pretty heavy clay too and on neighbouring plots the water does lie on the surface during the excessively wet weather.

Over the last three years I have dug in plenty of organic matter and sharp sand and this year I am trying green manures for the first time.

I have to say that although it is still heavy It doesn't get the waterlogging to the extent of other nearby plots.

[Rat]

Hi all, new to this forum after hiding in the shadows for a while. I'm a pipelayer to trade(for the next couple of weeks anyway) and for any land drains to be effective they really need to be about three feet down as their purpose is really to lower the water table. For the purposes of your lotties or gardens I would suggest that the problem is probably one of surface water not draing away quick enough and getting stuck on top of your clay pans, so I would recommend you use the ditch / French drain option, in a herringbone pattern as previously mentioned.
If you use pipe, clay tiles will "draw" water for 11 yds each side if three feet down or deeper without anything to assist other than a pea gravel bed to set the tiles on, whereas the modern perforated plastic require a good 4 inches of gravel (20mm washed gravel is what we use) to enable it to have the same draw.
Just remember to start at the outlet point and work back towards the problem area allowing a fall - you can lay pipes dead level and the water will still flow to the outlet.
Cheers
Rat

[oldherbaceous]

Good afternoon Rat, and a very warm welcome to the forum.
And may i just say what a very useful reply to this topic.
Hope you enjoy yourself on the forum, and no more hiding in the shadows please.
Please feel free to join in any of the nonsense, sorry i mean topic's.

[peter]

A hearty welcome and one of the best debut posts I have seen.

[tracie]

To Rat,

Thanks for your posting it was very helpfull. I have already dug the trench to drain the water away. Do you recomend pea gravel or could I use a larger grade of stones for the trench.

Thanmks once again