Soil mix question

[Johan]

I have recently changed over to raised beds:
http://www.growfruitandveg.co.uk/gra...ter_76879.html

The second bed is now complete and filled with 8 inches of mushroom compost, but not digged. The first on was digged to 12 inches, giving a soil mix of 25% soil (sand) and 75% compost). This mix is 12 inches deep, above soil.

I can hear mus stuff grow. Visitors started the same sowing time as me asked me what I do to get the stuff grow so fast. My first cucumber was harvested before their's even flowered. My Swiss Chard is growing very large. The squash and pumpkins grow like never before. I however experienced signs on the pepper leaves that there is a calcium shortage, but there is no blossom end rot so far. The soil mix keep very damp. there is no signs of wilting. Even above 40 degrees of C / 106 degrees of F. I know mushroom compost is not the richest of compost but it is very good still.

What difference can I expect if I do not dig the second bed? I know the soft part then will only be 8 inches deep. I am planning to dig but I am curious.

[Bigmallly]

I would assume it all depends what you are growing in bed 2. Will they have shallow or deep roots?. As with all of us, moisture is important but more so for you with the temps you are recording. I don't think you can overdo any organic matter.