[Eightball]

I got an allotment in september (half plot). The previous owner was on the committee, actually think he is the chairman but anyway it has a problem with drainage. The whole site slopes from south to north. I think there is a SLIGHT slope from east to west as when i dumped some water from bed 1 behind the shed (there is a tree there) the water flowed down from there and back into bed 1 where it came from! Anyways yes the previous owner moved to another plot so obviously that doesn't bode well. I think he wasn't well for a while or something because the treasurer (person ive been dealing with on the committee) told me the plot hasnt been worked for about 8 months. Anyways here is a picture of my plot.


where my bike is north and where the shed is south, so the slope is in that direction. I have 3 beds and have labelled them accordingly 1, 2 and 3. The plot hadn't been used for almost a year so there were a lot of weeds. I have been clearing them slowly but surely. The treasurer mounded up the earth in the three beds so the water seems to run off into the areas I have circled. Also I should add there is a band of clay running through the allotment site and it goes through my beds (1 and 2 mainly)


In bed 1 I was working my way down to the end and was clearing the trench of weeds but had to stop halfway through. After that it rained like crazy again and because I had dug part of the trench the water pooled as you can see from the above/below photos.



It has been like this ever since that time because it wont stop raining. At one point it did start to go down but then BAM! it rained loads again and filled up. I have been scooping up the water from bed 1 and moving it via buckets onto bed 3 as it seems to drain a little better there. The water does pool in the small trench in bed 3 but seems to drain unlike the other 2 beds.

Bed 2 doesn't flood as bad but its still a problem at the bottom end of the bed. see pics below:


I have been waiting patiently for the soil at the end of the beds to dry a bit but decided enough was enough with bed 1 as it was starting to smell, I guess because the water was mixing with the mud unlike the ditch in bed 2 which is filled with grass. I decided to dig a longer trench in bed 1 to hopefully stop the water standing in one small area (see pic below)

Not sure what I did was the right move but not really sure what else to do. Should I just leave that area until next year and hope we get a dry spring so i can do something with the ground? Any advice is welcome. My plot seems to be the ONLY plot with standing water. Everywhere is wet but nothing like mine. Probably because it hadn't been cultivated for a while and was very weedy, mixed with the clay and maybe some compaction. I don't think french drains would be a solution either because im surrounded by other plots so not really anywhere as an outlet as I can't go digging through other peoples plots!

So anyway are these trenches that were dug a good idea? i'm starting to think not and they seem to just invite water to sit there and stagnate (it smells!). I'm planning on double digging the whole plot when I can. Waiting for the allotment to get a delivery of compost in november so i can work that in as I go. Just need some advice on where to go from here. Don't really want to write off part of my plot.

Should I fill the trenches in and try and raise up the whole bed with compost?

PLEASE HELP!!

[Eightball]

Its not all doom and gloom though as I have planted LOADS of onions where the netting is and plan on getting some garlic in the rest of that bed in the next week or so.

[sunshineband]

The bed you've planted up seems in good condition  

Clay is not the end of the world, as lots of us have found. Diggin in lots of organic matter and sand helps, or some have made 'lasagne' layers over it and planted into that.

Either does the job, just make sure you have poked down as far as you can with the prong to make sure there is not a solid pan of soil near to the surface, or areas will fill up like sumps.

Your drainage ditches look like they are doing the business

[Fisherman]

You don't say where you are located Eightball so perhaps you could update this on your profile as it does help understanding what part of the country you are from in order to give advice. This year has been unusually wet so it may be best to just dig over your beds when conditions permit and then see what the ground is like next spring. Adding compost, manure, sharp sand etc will help the drainage. Also take advice off other adjacent plot holders.

For information - my plot has been exceptionally wet since April and I have an underground drainage system. Point is your plot may not be as bad as you perceive it to be under normal weather conditions.

[angelavdavis]

As sunshineband says, you can raise the beds which will help the drainage.  A lot of plots have suffered with heavy rain this year - even the water butts are overflowing!  Improving the soil with composting material, sand and fine grit will help with drainage in clay soils.  I use the lasagne bed method mentioned to great effect on my clay soil.  

It is a concern over the smelly water/soil though.  It could just be stagnant from heavy standing water mixed with manure, but it could even indicate a leak from a pipe somewhere.  Do you have manure stacked nearby? (I couldn't see anything on the photos).

Any way of finding out if there is a sewer or drain near your plot?  Does your committee have any sort of site map indicating drainage across the site?  

[syks grower]

I had the same problem on my first plot.

I found that digging deep sump holes realy helped. i dug holes 24 " square 30-36" deep using the topsoil on my beds, I put some wood over the top to prevent anything falling in.

4 of these down the outside of the plot really made a difference.
they were always had water in even if we had no rain for weeks

[TerryB]

I'd dig a good deep trench along your southern fence, line it with weed fabric and fill it with stones, broken glass, etc.
Top of with wood chip and this can be your main path on to the plot.
The soil can be put on the beds.
If need be you could also put some trenches alongside your beds.

[TerryB]

Sorry just read your post again a realised the north fence is the lower so put your trench along your north fence.

[gremlin]

I sympathise. My plot was much the same when I took it on. I think the Oxford clay covers Berkshire too.  I think the problem is that the top surface of the soil has been compacted by walking on it and wont let the puddles drain. Once I had dug over the whole of my plot to one fork depth  and left it loose, I don't get puddles any more. Some manure and compost has gone in, but not that much really

The joy of my clay is that when it dries out it suddenly sets like concrete and needs a pickaxe to dig it. Seriously.  I have a very narrow weather window in spring between undiggable bog and undiggable concrete.

The good news is that if it was the ex Chairman's, it is probably one of the better plots on the site.

[angelavdavis]

I noticed a tweet from RHS on drainage and thought it might be useful to some (no big surprises from the suggestions already made on here but it is here if anyone is interested):

http://apps.rhs.org.uk/advicesearch/profile.aspx?pid=475

[Eightball]

Thanks for all the advice. I think i'm just going to leave it for now and see what the situation is in spring/summer with that end of the allotment. Maybe improve the trench if it fully drains at some point.

I will work on the areas that aren't so bad and try and incorporate manure, compost and sand into the soil when I can. If the water still doesn't fully drain by summer I might just use it as a mini pond and put water plants in it to filter the water, I was thinking maybe water hyacinth as they are supposed to be very good at filtering water.

I am going to double dig my plots and incorporate sharp sand and then manure/compost into the trench. Hopefully that will improve the soil. Toying with getting rid of the grass paths inbetween my beds and putting in woodchip paths but i think i will wait on that till next year.

and in answer to your question before angelavdavis I haven't seen any manure pile and don't know about any drainage map. I will see what next year brings tbh.

[Kieronl]

Looks very much like our plot. In the end we went for raised beds with a couple of land drains in, but still its been underwater much of the summer.
Its odd how water can behave my plot is much wetter that my neighbors which is downhill so to speak of mine.
As others have said sand and organic matter  dug in may help, but for me raised beds allowed me to get good crops
But good luck and have fun

[Eightball]

how much sharp sand should i work into the soil? I plan on double digging and adding sand and compost to the trenches. Two of my beds are roughly 2m x 5m and one is around 2m x 2m.

Wickes have an online deal where if you buy 10 bags of sharp sand they are £1.18 a bag. Would 10 bags be enough for this kind of area?

[crh75]

I don't know a definitive answer, and it would depend on your exact conditions anyway.

Ten bags works out at less than half (0.42) bags per square metre.  I would think you would be best using more like 1 bag/m².