Polar Bear Zinnia Seeds

Sow Zinnia Polar Bear seeds directly into the garden once the last frost has passed and the soil reaches 70°F or warmer. Plant them a quarter-inch deep, 9 to 12 inches apart, and cover lightly with fine soil. Germination runs fast in warm conditions, normally 5 to 7 days. You can start Polar Bear Zinnia seeds indoors about 4 weeks before transplanting, but plants hate root disturbance, so use cell trays or peat pots that go straight into the ground. 

Polar Bear Zinnia needs full sun, at least 6 to 8 hours a day, to produce the dense double blooms. They can grow in almost any soil, but give them well-drained, compost-rich loam at a neutral pH and you will get taller stems and bigger flowers. Water deeply at the base of the plant once or twice a week, and avoid overhead watering as it causes powdery mildew. A two-inch mulch layer holds moisture in the bed and keeps the soil cool through July and August. One feeding of balanced fertilizer at planting is enough for zinnias flowers.

Pinch the central growing tip once the plants hit 8 to 10 inches tall to encourage branching. Deadhead spent blooms regularly to keep the flower producing buds from July to October. For cut flowers, use the wiggle test — grab the stem about 8 inches below the bloom and shake it gently, and if the stem stays rigid it's ready, but floppy ones need another day or two.