Flickr) and so is the rest of her garden set, by the by. Moonflowers open up after sundown. I've heard (since I don't have one of my own to learn from yet) that they become bushy and about 3 feet tall. I only have a few potted plants that I'm mothering at the moment and not enough room to house a plant that size. I'll have to convince my mother we need some Moonflower in our front garden. It would be so beautiful to come home to after a long day, don'tcha think?