Some good choices are: zinnias, pentas, lantanas, marigolds, petunias, torenias, and impatiens. Annual vines, like cypress vine and morning glory, will grow rapidly and bloom through the fall. Vegetables: Tomatoes, cucumbers, peppers, zucchini, broccoli, and lettuce and greens are good candidates for pots Here are the common problems a gardener may have with a rooftop garden.Accessibility to water and drainage issues.A way to bring gardening supplies to the roof.Storage.More extreme weather exposure to your plants.Privacy.Structural issues with the roof.