Blue Sky Vine (Thunbergia grandiflora) is a vigorous twining plant that grows in Zones 8 to 11. The large bluish-purple flowers appear in the spring and bloom periodically throughout the summer. Blue Sky Vine is easy to start from seed and grow.
Buy Blue Sky Vine seeds or plants from a trustworthy local or Internet nursery. Buy seeds at least 6 weeks before the predicted date of the last frost in your area. Buy plants in spring, summer or fall. See Resources for some Internet suppliers.
Plant seeds 4 to 6 weeks before the last frost. Sow 2 or 3 seeds in a small pot of fine textured potting soil. Place the pots in a bright, warm location, and water regularly.
Choose a location in your garden in full sun to partial shade with rich organic soil. Install a trellis or arbor to support the vines in the location you have chosen.
Use a trowel to dig holes for the seedlings or a shovel to dig holes for the nursery-bought plants in the ground when the temperature no longer drops below 50 degrees at night. Place the plants about 3 inches from the support, so the plants can twine around it.
Water well until the plants become established. Blue Sky Vine is somewhat drought tolerant but grows better with regular watering.
Use hand pruners to removes excess growth in the spring after the first flush of bloom to control the plants’ size and direction of growth. You may have to prune the plants several times a year to control their growth. Remove old stems when they begin to lose their vigor.
Blue Sky Vine is susceptible to attack by spider mites. If you see any spider mites, use Neem Oil at the rate recommended by the manufacturer for control.
Blue Sky Vine slows or stops growing during periods of cool temperatures. If the cold kills the top of the vine, remove dead limbs in the spring before new growth appears.