I grow several types of beans in the garden, but the growing season is too short for chick peas. If I use a different bean - e.g., kidney, navy, cannelini, turtle (black) beans - do I need to make changes to a "standard" falafel recipe?
I know this question has been answered but I wanted to add that Akara is Nigerian dish similar to falafel and is made with black eyed peas instead of chick peas. There are also regional variations across Africa, Brazil and the Caribbean with different names.
Recipes for Akara in addition to those for falafel may help you come up with some better ways of using the beans and lentils you have available to you.
Yes, you can, however if you want to use red kidney beans, or white kidney beans (cannellini), please boil them at least 30 minutes at 100 °C, otherwise you might suffer from food poisoning. Source: https://en.wikipedia.org/wiki/Phytohaemagglutinin
Regarding taste, in the original recipes there is no need for eggs as an binding agent, so you can taste as you go. Go with the usual onion, garlic, fresh parsley, coriander, cumin and flour (+ obvious salt and pepper to taste), but you can add also a bit of mint and/or rosemary that goes nicely with the beans.
Also, you can do test ping pong ball sized specimen, fry em up, and taste which one is the best, then season accordingly the whole batch before frying.
Green lentils are a good replacement for chickpeas in falafel. There are many recipes available online for such a substitution. Like chickpeas and unlike many other beans, lentils do not require boiling (you can just soak them for a long time) to make falafel. I can also confirm from personal experience that green lentil falafels usually taste great.