Care of a Thunbergia Grandiflora

Place a trellis in rich, well-draining soil in a sunny spot that receives afternoon shade. Dig a hole with a shovel near the trellis, so that the hole is twice as wide and the same depth as the root ball. Place the root ball in the hole and gently cover with soil so that the top of the root ball is even with the soil’s surface.

Water the vine keeping the soil moderately moist. Adding 3 inches of pine needles or bark mulch to the soil preserves moisture. Keep the soil consistently moist but not waterlogged. Water it thoroughly every week or two during drought periods.

Add 10-10-10 fertilizer according to label instructions in early spring and early summer if soil tests indicate nutrient deficiencies. Skip this step if the plant has lush, dark-green foliage and is vigorously growing. Avoid heavy fertilizer use, which may cause this vine to develop excessively long stems that spread into other garden areas.

Secure the rapidly climbing stems to the trellis with twine. Train the stems with twine to direct plant growth within desired boundaries.

Control pests, such as spider mites, scales and whiteflies, by washing them off with water or by applying pesticides. These tiny bugs feed on stems and the undersides of leaves and cause leaf discoloration and defoliation. Apply bifenthrin, permethrin, pyrethrins or horticultural oils according to label directions.

Prune back unwanted growth with lopping shears whenever the vine develops gangly, out-of-control stems. Prune dead, frostbitten stems and foliage to the ground in the fall. The vine resumes growth in the spring.