Flower of Ipomoea alba, the moonflower, photo by Lyn CoxThe night-flowering moonflower vine is a twining climber from tropical America, that can grow to a spread of 5 to 10 m. Grown from seed in early spring, it rapidly ascends any nearby frame or fence. As summer days heat up, the moonflower will develop long, slim buds like unfurled parasols, and each evening a few flowers will open. The huge scented blooms, with petals like some superb fabric, actually unfold before one's eyes over the period of a few minutes at twilight (click here to see it happening in real time), and then they collapse around 8.30 or 9 am. They would be worth holding a party for, so that all one's friends could admire them! They bloom for several months. I have read that the flowers are quite resilient and can be picked to arrange indoors for an evening display, though I have yet to try this. I enjoy growing mine on the pool fence, which I can see from my bedroom window, so I can see the moonflowers each morning before they wilt.
Moonflower seedlingIt is best to nick the seeds with a scalpel or Stanley knife then soak the seeds overnight before planting them directly into the soil, as they are extremely hard. A sunny position is best, with a sturdy support nearby for the vine to climb up. They can also apparently be planted in a large pot, though I haven't tried this. They need a reasonable amount of moisture; otherwise the leaves may wilt on hot, windy days. Perennial in their natural habitat, I gather that in our climate the moonflower is an annual, being sensitive to cool winters, and it is probably just as well, because otherwise it might go berserk. I would advise pulling the old plant out at the end of autumn and making sure the seedpods are removed so that it can't self-seed where you don't want it or escape into bushland. Save some seeds to plant out next spring. Note that the seeds are poisonous if ingested so keep these away from children and animals.
Best grown from seed.