Days to maturity can be affected by quite a few factors. Lima beans require warm weather to grow well and mature. If conditions are cool, they may take a long time to develop pods. Some varieties mature faster than others. Most are rated at 75 to 90 days from emergence to first production of harvetable seed pods. It normally takes about another month beyond that for the pods to completely mature and dry down if you're wanting to harvest dried limas rather than baby limas.