Running out of gardening room? Try the roof. This one is lit at night and it looks good day and night. The evergreens give it year 'round appeal. There are no chickens, dogs, cats or sheep in it. Goats could be in it. I think they could jump on a low flying plane if they wanted. They are big time jumpers and munchers.
Unfortunately some roof top gardens are the unwanted ones. Sprouting tree seedlings in rain gutters. Rain gutters always need to be cleaned of debris to keep them from clogging and filling with water. The weight of water will cause them to pull away from the house.
Other gardening spaces are windowboxes and movable pots. Pots are great because you can move them (providing they are not too large) around an shaded outdoor dining table when entertaining and then move them back into full sun the next day.
Have fun in your garden wherever it is.