Thanks for writing. How's your soil? Peppers are considered heavy feeders, so if your soil is poor or very sandy so it doesn't hold nutrients well, your peppers may need additional fertilization to keep them growing. Or, you could also try growing them in containers with a high-quality potting mix.
Do you grow the same variety of bell pepper every year? If so, you might look at different cultivars in case the one you have experence with isn't well suited to your area.
---Justin, Senior Garden Editor, BHG.com