So, how do I go about this? My soil is fundamentally clay, but I want to grow terrestrial (meadow) orchids that don't like a too high fertility. Wet/moist isn't so much a problem since they like that.
If I had to guess I'd remove the turf, dig it over to a fork's debt and then sow some heavy feeding crops to draw out all possible nutrients. After that remove the dead/dying crops and dig in leaf mould; to build some humus and soil life, but without all the nutrition. No?
Or perhaps keep the turf, scratch it vigorously and let it grow wild while planting the orchids in between. Mow it in autumn and remove the clippings without ever fertellizing?
