Moonflowers and morning glories are twining vines belonging to the Convolvulaceae family. Both plants produce trumpet-shaped flowers. Morning glory flowers are unscented and grow in several different colors. The sweet-scented moonflowers produce only white flowers. These vines grow quickly and easily by preparing the seeds before planting. Morning glories are so named, because the blooms open in the morning, while moonflowers open in the evening. Plant them together, and enjoy morning glory blooms during the day and moonflowers at night.
File or chip the hard outer shell of moonflower and morning glory seeds, and soak them for 24 hours in warm water to speed up germination. Soaking the seeds softens the hard outer shell for faster germination. Filing or chipping the outer shell, before soaking, guarantees even greater success for speedy germination.
Start the seeds indoors at least six weeks before the garden soil warms. Plant the well-established seedlings in full sun. To grow hardy seedlings indoors, plant the seeds in peat pots or containers with potting soil, and place them in a sunny window or under fluorescent lights. If you place the seeds in a window, move them away from the cold window at night. Your growing room must be warm for successful germination. If the room is on the cool side, place heating units under the growing containers. Heating units are available over the Internet, and they can be expensive.
Plant moonflower and morning glory seeds in average, well-drained soil, in full sun and sheltered from strong breezes. Provide a sturdy support such as a trellis or fence for the vine to climb. Moonflowers are vigorous, heavy vines and can break down a weak support. Cover the seeds lightly with about 1/2 inch of fine soil. Firm the seeds lightly, and keep them evenly moist for successful germination. The seedlings emerge in about seven days. When they reach 1 to 2 inches tall, thin the seedlings to 12 inches apart.
Moonflower vine climbs by twining. If you live in a region with a long growing season, the vine can grow to 30 feet high. In short-season areas, you can expect it to reach a height of 6 feet. The flowers open all at once with a faint popping sound.