You can even sell the crops you grow at the local farmer's market on Saturday mornings. If you already have the land and the desire to do this, why wait. Start it part-time if you want, but you may find dozens of outlets for your goods if you are up to the test. The risk is bad weather, of course, but it's a chance worth taking if you love gardening. Commercial building maintenance people are often on the lookout for good help in this area.
People hate to do windows.
You can charge per house or per hour for commercial buildings. If you're good at giving massages, consider getting a license or certification to be a massage therapist. Health clubs, running clubs, and conventions are all good candidates for your work. Arm, hand and back strength are particularly important. If you like to cook, consider the catering business.