TO START OUTDOORS
In late spring, once weather is warm and settled and nights stay above 55°F (13°C), plant seeds in a sunny spot in ordinary garden soil 2 to 3 inches apart and 1/2 inch deep. Firm soil over seeds. When seedlings are several inches tall, thin to 6 to 8 inches apart.
TO START EARLY INDOORS
Sow indoors 4 or 5 weeks before last expected frost in individual pots of seed starting mix. Cover 1/2 inch deep and keep warm and moist. Provide a strong light source until seedlings are ready to plant outdoors. Plant out only when nights reach 55°F (13°C). Transplant seedlings 6 to 8 inches apart, taking care to avoid disturbing roots as much as possible.
Morning glory seeds have a very hard outer shell. To improve and significantly hasten their germination rate, it is worth the extra effort to use a nail clipper and nick each one just enough to break the seed shell so soil moisture can enter more easily. Alternatively, you can rough these hard-skinned seeds with a file. At planting time, erect well-anchored supports at least 8 feet tall. Morning glories bloom abundantly beginning in mid to late summer once days begin to shorten.