I have some leftover from last year and I wonder if it is still good?
I hope so. That's what I've been using!
Does innoculant really help? I never use it and don't seem to have much of a problem. What does it do for the plants that compost doesn't? Does it increase yield?
I really had difficulty getting beans & peas to germinate & grow before the first time using inoculant. It's suppose to supply some beneficial bacteria to the plants, giving them more rigorous root growth. I used some on the new section of the garden that hadn't been planted before. Using it once is suppose to ensure that the soil has the right bacteria to promote root growth.
From what I've read here, it has helped some people (like me!) but most don't see any significant difference. If you are already growing beans successfully, you probably don't need it.