Hi Charles
I too have had considerable problems with New Horizon multi-purpose peat free compost. I sowed sweetcorn, summer and winter squash and cucumbers in large modules at the beginning of May. When I opened the bag I knew I was in trouble because the texture was so coarse with recognisable twigs and uncomposted wood about 3cm long. Within 4 days the surface of the compost was covered with a white mould. Later, once the seedlings appeared, tiny mushrooms also developed. The compost holds a lot of moisture and even though the surface may dry out, underneath this crust the compost is very wet.
The plants look pale and puny; the sweetcorn leaves are thin and yellowing at the tips, I don’t think I can use them.
( As an aside: Is it too late to direct sow sweetcorn?)
The squash is also pale and has taken an age to develop their true leaves. Does this indicate a mineral deficiency? This compost is supposed to have enough nutrients for 4-6 weeks growth.
Reading around this subject on the web the common complaint about peat free compost is inconsistent quality and the absence of an industry standard to refer to.
I noticed Charles that you have done several comparison trials on compost in recent times, but if each company isn’t providing the same product from one year to the next the trial results are very quickly obsolete. New horizon MP compost, for example, was reformulated for 2014, which may explain Dan’s problems.
Is there a peat free compost you would recommend?