Before I talk about some of the methods for making money online, I wanted to address the role of pain versus pleasure. Every decision that we make in life is weighed on a pain-versus-pleasure scale. We will always do more to avoid pain than we will to gain pleasure, plain and simple. However, this is also what holds us back from succeeding in any endeavor.
I think you can do well with this business if you start with people in your neighborhood and ask them if you can have an opportunity to perform this service for them. Word of mouth will travel fast if you provide a good value. I think the key to doing very well here is to package your service. For example, try to find a price that works for mowing, weeding and fertilizing altogether.
You could try advertising more, for example, by putting up signs around the neighborhood, posting about it on social media, or having people you know spread the word. You could also try doing it in a different neighborhood that might have friendlier people, or do it in a time and place where there's likely to be a lot of people walking around the area (e.g., near a church before the end of a mass).
Start a photography business and sell your photos online. If you have a nice DSLR camera and take good photos, do photography sessions or take photos of events, like parties and weddings. As another option, create fine art photos that people may want to hang on their walls, or take stock photos to sell online on sites like iStock Photo, Shutterstock, or Alamy.