Hi

I am preparing my raised beds for some early spring sowing. I put in some manure a few months ago. Over the last year or so the beds have really settled down and so there is plenty of room to add more to them.

I was wondering if it is better to add pure compost or topsoil or a mix of both. Does pure compost have all the nutrients a vegetable needs, and do the nutrients last very long, or is topsoil longer lasting? Also, what is a "soil improver"?

My soil is tending towards to clay side of things.

Thanks for any advice.