Have you ever tried growing spinach in mushroom compost? I did that one year, and it produced 100% better than any other combo.
Funny you mentioned mushroom compost— I saw it at Home Depot and remembered your post on the subject. Didn’t buy it but I added my own homemade compost to the clay soil and tried both seeds and transplanted spinach seedlings but zippo. My gal pal she buys her spinach plants and has better success when transplanting. So maybe next time I’ll use your mushroom compost suggestion—hey maybe for the Fall planting. Maybe the swiss chard will work well too in it since mine went the spinach bust route too. Danke....