[heygrow]

I have just extended the area of my vegatable plot and need to bulk it out with some more soil.... probably need to add about 6 inches deep. Should I add Top soil or some other type of soil?

The subsoil is very clay based and currently of top of that there is a mixture of rotted down wood bark and earth. I plan to dig in some manure/compost later this year as well.

[sunshineband]

Top soil is pretty expensive (check out Dandystopsoil as one of the cheaper suppliers) and you need a fair amount to raise the level by six inches.

If you are not in a hurry to raise the level, you can just do it year on year by adding home made compost, spent grow bags etc as you said.

There is not really any other sort of 'soil' you could add

[Yorkie]

Do not try to add or incorporate subsoil.  It is nutritionless and has no structure.  Won't do the plants any good at all.

[heygrow]

OK thanks for your answers. It was the guy at the local garden centre who throw me. He said 'you don't want topsoil', but suggested I fill it up with multi-purpose compost! I was not convinced.

Yorkie, what do you mean by subsoil?

[bigben]

OK thanks for your answers. It was the guy at the local garden centre who throw me. He said 'you don't want topsoil', but suggested I fill it up with multi-purpose compost! I was not convinced.

Yorkie, what do you mean by subsoil?

You would be ok adding some compost to bulk up your plot. This would add organic matter to the soil which is needed but would eventually rot down.

Sub soil is -as the name suggests- the stuff you find under the top soil. Think about what the bulldozers are pushing around when they build new roads. It is lighter coloured - often yellow with stones. It does not have organic matter in it nor worms and other soil life. Top soil is the darker layer the worms have penetrated with organic stuff that has rotted down and been incorparated into it.

[Yorkie]

+1 with Bigben's comments!

[rufty]

I thought you wanted to occasionally work the subsoil though otherwise you got a hard pan which was really bad news for drainage and any plants that needed deep roots?
Also I understood on clay soils that in small doses clay can be a good source of nutrients and good for holding moisture, the key was to make sure the clay (in small enough clumps) got brought to the surface where winter frost could break it up for you.

So that was why when you dig the soil for potato planting you did partially break up the subsoil, but because it only happened once every 4-7 years it was in small enough quantities that the rest of your soil care regime made sure that there was enough vegetable matter.

[Yorkie]

There is something in your observations, rufty.

If there is a drainage problem then I would investigate the subsoil to see whether there is a pan.  Otherwise I would not bother as it clearly isn't causing a problem.

I was taught when I did a gardening course not to try to bring subsoil to the surface in any quantities in an attempt to convert it to top soil, as that would be an incredibly long and fruitless exercise.

But trying to break up a pan by a little forking over wouldn't hurt.

[sunshineband]

The bottom end of our plot had a very hard pan of solid clay and stones about a foot down. I dug out a trench of the top soil so I could dig the sub soil without bringing it up to the top, and then filled in the trench agian with the top soil.

With a bit of barrowing, you can do this across a section quite easily --old fashioned double digging I think it is 

Worked a treat - drainiage is much improved 

[mumofstig]

called something completely different by the old boys on our site 
link here

It makes I larf **snigger**

[snowdrops]

called something completely different by the old boys on our site  
link here

It makes I larf **snigger**

Your links not finding anything.
Double digging is what was known as bas*ard trenching I believe

[sunshineband]

called something completely different by the old boys on our site  
link here

It makes I larf **snigger**

Your links not finding anything.
Double digging is what was known as bas*ard trenching I believe

I was being polite 

I think I know why it has the name --- 'cos it is a real bas$£@rd to do 

It was certainly worth it. I dug half the plot in this way, and it meant I culd take out the weed rootd and all nearly all the wireworms as well. As the plot had been deemed unusable because of the wireworm population, I got it quickly, and was so excited I did all the digging in about a month. Took out a mountain of stones too -- good hardcore for the shed base  )

(Top half was just single dug, and laid to raised beds in Year 1. Bottom half had spuds year 1, but is now rasied beds as well)

[snowdrops]

Yes I do believe that's why it's called that. Sounds like you have done enough digging for a while! You must be reaping the benefits & will have impressed all the old boys on the plot

[Grubbypaws]

I have just built a new 8 foot by 4 foot raised bed. I have filled it entirely with home made compost; cost £0. I was really pleased with my self but hope it is OK to have no top soil in it at all.

Reassurance would be most welcome!

[mumofstig]

is the bed over earth or over concrete?