Look, your neighbor was gracious enough to loan you their power equipment for the job you wanted to do on your own home. It really should go without saying but it was, in fact, your responsibility to return it back to him as soon as your were finished. This not only shows your gratitude but also helps maintain your neighbor's confidence in you and others when someone needs to borrow it the next time.
Don't until it's too late
It might feel like it's been so long and you're too embarrassed to return the equipment and because of this, you opt to wait it out in hopes that it never comes up in conversation. This is unlikely. You can rest assured that someone who loaned you something likely never forgot about it, even if they never bring it up.
Normal people hate the idea of owing something to another person. The mere thought of it eats away at them and the reality is almost too much to bear. It's precisely for this reason that they do everything in their power to return borrowed items back to their rightful owner with a sense of urgency. You should make every effort to implement this very practice.
Do the Right Thing
Whether it's a leaf blower, hedge trimmer, lawn mower, or even their ladder, your neighbor did you a solid. The least you can do is return the item to it's rightful owner without them needing to ask. Return the things you borrowed in the same or better condition than it was when you borrowed it. This will help ensure it's available for you the next time.