Zone 5 and until I did a recent soil test, would've bet the farm the
garden was 100% clay.
Now I now it's only a little clay, but you could hurt yourself in the
middle of summer if you try to dig out there!

I have recently found the best thing I can do for my garden is to
compost in-place. The two beds I did that to are now almost
potting-soil consistency. Really good stuff.

I've tried:
Adding peat, adding sand, adding leaves tilled in in the fall, manure
overwinter, green manure, bringing in topsoil, digging, cultivation..
none of this work can match whatever the compost does.

Raised beds, 2.5-3 feet wide. Currently have 3 beds with 2.5 feet of
rough compost on them, 8-9 inches of straw and aged manure on it over
asparagus beds, back corner where weeds got ahead of me this year.

2 cold frames, one is empty the other has sorry looking lettuce
remnants that if I'm lucky will go to seed this spring in another 7-8
weeks.

Hoophouse looking forlorn with the 40-50 degree temps lately and
nothing planted in there..