Not bitter at all, my father loved the salad. Was nothing left, and he is more sensitive to bitter things then me. He wont eat just Arugula or anything like it even with dressing.
Dandelion greens, lettuce+arugula flavor with slight bitterness at the end (2 or 3 out of 10 for bitterness). I make sure to harvest younger tender dandelion greens with less bitterness (I have been selectively culling bitter tasting dandelions in the garden, I let the the good tasting ones stay and go to seed. About 30% or so of the salad.
Malva. sp is a very neutral lettuce type taste green. Great additional to any salad does not overtake any taste and enhances the texture and subsistence of the salad. About 20-30% of the salad was this. 1 out of 10 for bitterness.
Nasturtium has a peppery spinach flavor on the leaves, flowers are a sweet peppery flavor. About 10% of the salad.
Silene inflata has a mellow arugula taste with a slight herbal aromatic finish, bitterness is on the lower end on this (2 out of 10). 10-20% of the salad.
Plantago coronopus, has a great mild lettuce like taste. 1 out of 10 on bitterness. About 5% of the salad.
Plantago common, has a unique earthy nutty taste with a sharp finish. I make sure to get young leaves to reduce the bitterness. Bitterness 4 out of 10. About 5% of the salad.
Garlic chives, excellent flavor added with no bitterness. Just a nice slightly sweet garlic+chive taste.
On the bitterness scale I would say Spinach is a 2 out of 10, and Arugula is a 4-5 out of 10. Raw Aloe vera with skin is a 7-8 out of 10.
I find when the salad is well balanced with different greens the bitterness factor goes down by a lot. The next salads are going to become more creative
, with Kale, Toona sinensis, and others.