Morning glories are early risers, unfurling their magnificent trumpets with the first light. Each flower lasts only a day, but the vines produce many pink, blue, white, or fancy bicolor flowers daily. Plant seeds when night temperatures are consistently above 50°F, and thin them according to package directions. Three vines on a trellis or tepee will be plenty. They grow fast, twine lustily, and bloom until frost.
Morning glories grow from hard seeds; many gardeners recommend nicking the seeds with a file or soaking them overnight to encourage germination (use this trick with sweet peas, too). Soak for a maximum of 8 hours, and nick them if you like—but waiting until warm weather arrives is more important than either, Shepherd says.
Alternative for night owls: Moonflowers are comparable to morning glories in every way, except they open at dusk. If you time it right, you can watch the fragrant white blooms open before your eyes. They flourish in areas with long, hot summers.