@Amanda1341 I think this would be an attractive feature for guests. When I'm traveling to places with warm climates, I tend to prefer renting places with a pleasant outdoor space to have breakfast or aperitivo, since that's a luxury I don't have at home. I guess smokers who aren't allowed to light up indoors would also appreciate it.
If the garden were sheltered enough to offer some measure of privacy, I think it would increase the overall appeal and value of the listing. Only drawback is, once a feature is included in your offering, guests will judge their experience based in part on that feature"s condition. So to keep up your good reviews /ratings, you'll have to keep that side garden clean between all guests just like the bedroom and bathroom.