rotavating clay soil

Hi everyone, I'm new to this site, and new to gardening as well. I have just bought a new house with a small garden (roughly 10x10m), the previous owners didn't really care about gardening and they built two huge sheet metal sheds at one end of the garden, put loads of paving slabs at the other, and put a gravel pathway down the middle. Well, to cut a long story short, 3 months later, we have a small patio area, the sheds and the rest of the slabs are gone and we're left with a plot of land that has had nothing growing on it for at least 10 years. the soil is very heavy clay and we've dug in the gravel and the sand that was under the paving slabs, we want to rotavate and then put down some topsoil so that we can grow a lawn etc... now i heard somewhere that it's not a good idea to rotavate clay soil, is this true??
(sorry about the long post).

 

Hi there and welcome - have I gardened on heavy clay for more years than I care to remember and thinking of the action of a rotavator, it could compact when wet as well as break up - but I haven't heard that its contra-indicated.

The method that works for me especially at this time of year - is to use a spade to turn large clods and allow frost to break it up (saves the blisters of breaking the clods up) - then after that spread a good mulch of composted organic material, or even grit and fork it in - and repeat every time autumn and spring.

I have never used top soil, as clay usually has so many nutrients that it is not really necassary - the critical thing is to get it to a workable consistancy - and that needs introducing something that will break the particles up and stop them sticking together - reduces the waterlogging in spring, and cracking in summer.

 

Hi Kira,

I'm also new to this site,what a good find.The garden in my old house was heavy clay and I purchased some powder from my local garden centre
which helps brak up the clay.Sorry I cannot remember the name but it was really successful and made light work of a otherwise difficult job.Patience is the key,because you have to leave the powder on the clay for several weeks before.
digging it over.
Happy digging!!

 

don't rotovate the soil unfortunately the only way to improve it is to hand dig it and add as much organic matter ie mushroom compost, well rotted manure as possible, theres no need to add topsoil when you dig the soil, rotavating just compacts the soil.

 

I would agree with the above comments. The problem with clay is poor drainage because the particles are exceedingly fine. It ideally wants a good helping of sharp grit or any other odd shaped bits. These create weaknesses, allowing the clay to break more easily, and make drainage channels. I put about three tons of 10 mil gravel on my borders in a garden of your size. Agricultural grit would have been a bit better, but your average builders yard does not have that. Sharp sand is also good, but I am told that ideally you want something more irregular.

Also you want to dig in as much organic matter as you can. It does two things. The bits have the same effect as the grit, they make channels. But also over a period of time organic matter combines with the very fine clay particles making them coalesce into larger particles, and hence better drainage. Organic matter also provides nutrients, but clay is already nutrient rich - so you are not doing it for that reason. I suspect the chemicals you can buy also make the clay particles coalesce.

Digging will make drainage channels. But if you do not alter the constitution of the clay, it will go back to what it was before. Do not walk on wet clay. Walk on boards if you must work in the wet. Whilst digging makes drainage channels, squashing wet clay removes them.

 

Just to add, the more rough breaking up you do and the more organics you incorporate into the soil the more you will encourage worms. They really are your gardening friends and over time will do a lot of the work for you if you give them a helping hand.

 

I have 2 flower beds about the same size as your plot. Over 25 years I have tried everything to reduce the blue clay (when the children were at home we used to model and fire it) to a more managable soil. What worked best was introducing peat and compost in fairly large quantities over the years, patience is your greatest asset.

 

Frogesque and Jaycee are quite right. Worms are your friends, throw them a party, with spagetti and party streamers!

Thereafter, you don't need to dig the organic matter in, just lay it on top as a mulch, and tell the worms to earn their keep. They will pull it down into the soil for you.

 

organic matter is far more important than grit in the grand scheme of improving clay soils. organic matter will help retain the moisture. clay has next to no organic matter in it which means it dries out quickly in hot weather. but also doesn't drain in wet weather.peterS is spot on with the worms, let them do the work for you, they will do far more good for your soil than any rotovator

 

wow, thanks for all the replies and advice. I've got a much better idea of what needs doing now. I also know where to come with any more questions! thanks everyone. x