boy, juicing spinach, with all that acidity, must not be fun. Chard has
similar amounts of oxalic acid. Why not try pea shoots? They grow all
seasons. I plant them whenever I have a bed free for a month. Buy the
peas for sprouting, not the expensive ones. You can jucie them until
they are 10 inches tall. Hoe them under after five weeks. If you want
fast growing and very spicy, mustard is a tremendous weed. Beet greens
are a possibility, though they will not be available immediately. They
might be amongst the best tasting. Kale tastes mild enough that I would
try that too. And if you like bitter, chicory takes off really fast
right now. if you are already picking carrots, their greens are a
possibility (a bit sharp).

I only juice the collard stems in the winter, and that only thoroughly
mixed with apples, celery, carrots or beets. Right now watermelon is
the best juice.