Hard clumpy Greenhouse soil

I have very hard greenhouse soil which despite digging over wont break up. any ideas to improve it, thin it out? I usually end up putting a cover of potting soil down and putting plants into this (talking bout vegetables not cannabis). greenfingers

Gypsum can break apart hard, compacted clay.

In addition to gypsum, add as much compost and earthworm castings as you can without over-fertilizing the soil. AACTs would be the next thing I would start tossing down.

A last resort method that can be considered is to get a tine fork and loosen the soil a bit without too much compaction. Then follow pretty much all of the former advice. Sometimes a site can benefit from a ONE time soil loosening either by hand digging or tillage, even as detrimental as those methods are. Gypsum will take forever! But will eventually work. Bare soil should never occur with compacted clay soil, always keep some form of mulch or cover over soil, especially after you have added lots of compost or ewc. I like to collect all of my woody herbaceous material at the end of the year and shred it, makes great mulch and compost starter too.