Grow plants and sell them. Pop them outside and sell from your doorstep or advertise online. Collect and sell seeds from your existing plants. Become a garden designer. Offer your skills if you have a talent for garden design Sell garden produce. If you grow too much sell the excess from the front door. Start a blog, place ads and earn money by writing about your experiences. Grow and sell Pumpkins at Halloween. Make Jams and Chutneys. Sell cut flowers fresh from your garden. Keep Bees. Sell Honey Got a large garden? Hire it out for camping. Or hire it out as allotments. Keep Chickens. Sell eggs. Create how-to Youtube videos.