Ipomoea tricolor. It is a great shame that so many gardeners confuse this tidy heirloom annual with the invasive weed Convovulus arvensis. Both share the name Morning Glory, and both have trumpet shaped flowers, but the similarities end there. Heavenly Blue morning glory seeds produce short vines bearing copious, huge, intensely blue flowers that open each morning and then fade to pink before closing for good in the evening. Every day more flowers open from mid to late summer. It looks spectacular climbing along a fence or trellis, with really large flowers that can only be described as Heavenly Blue.
Note: This variety is not an invasive weed.
It’s a shame that so many gardeners confuse this annual morning glory with the invasive weed, Convovulus arvensis, because this variety will not take over the garden. Instead, it will produce a lush abundance of big, intensely blue flowers from midsummer on. Continue reading below for tips on how to grow morning glory from seed.
Season & Zone
Exposure: Full sun
Direct sow where they are to grow 1-2 weeks after the last frost date. Or try sowing some indoors in peat or coir pots 3-4 weeks before last frost, but they do not transplant well. If starting indoors, chip the seeds and soak them in warm water for 24 hours, and then provide a constant soil temperature of 21-30°C (70-85°F). The seeds should sprout in 5-21 days, but may be longer outdoors. Be patient.
Sow seeds 5mm (¼”) deep. Space or thin to 30-45cm (12-18″) between plants.
Make sure to provide some support for these tall vines to climb up. Moist, well drained soil that is not too nitrogen-rich is ideal. Excess nitrogen leads to large, bushy vines with fewer flowers. Dry soil is tolerated. Pinch the tips of the plants as soon as you see them start to climb in order to produce branching growth.