Creating a seedbed

Hi Kajazy
I have not actually made or used an outdoor seed bed but if I were to I would create a raised bed maybe 1Mt x 2Mt but the size does depend on how many seeds you intend to sow. Ensure that it has good drainage by by installing some sort material below the compost (stone, drainage tubes etc.) Then I would fill it with either a good multi-purpose compost or John Innes seed sowing compost (recipe below) to a depth of about 6"-8". I think I would also make a cloche type cover for it in order to have some sort of control over temperature and watering.

John Innes Seed Sowing Compost
Sterilised Loam   2 parts   
Peat                      1 part and,
Sharp sand      1 part

Hope that helps

It would be useful to know what plants you're thinking of.

As Yorkie implies, the leap from a conservatory to a seed bed is a big downward one, temperature wise.

They should be fine, but you won't be able to do the early sowings - that's all 

brassicas will be better in a seed bed outside as they will be stockier as the ones sown in higher heat(as some clever person told me on this site last year) become spindly and are more prone to being knocked about by the wind.

I'd swerve topsoil if you can afford not to use it as you'll just import weed seed which will find it's way there by it's own.