Zinnia Seeds - California Giants - Zinnia elegans

2, 3, 4, 5, 6, 7, 8, 9, 10, 11

Zone-Specific Information
USDA Zones 2-11 - Grows as a warm-season annual across all zones. These plants are not frost-hardy and will die back with the first freeze.

Best performance in Zones 3-10 where long, warm summers provide ideal growing conditions for maximum flowering potential.

Northern zones (2-5) - Direct sow seeds after all danger of frost has passed and the soil has warmed. In regions with very short summers, starting seeds indoors 4-6 weeks before the last frost can provide an earlier bloom period.

Hot climate zones (9-11) - Zinnias thrive in heat. Plant in early spring for a summer-long show. In extremely hot areas, providing afternoon shade or planting in a location with partial shade can help prolong blooming.

Soil temperature critical - Requires warm soil of at least 70F for optimal germination, with seedlings emerging quickly once soil temperatures are consistently warm.

Growing season needs - Requires 60-75 days from seed to bloom and will continue to flower until the first hard frost, making them a suitable choice for a summer-long display in all zones.

Learn more about USDA Hardiness Zones here

When to Plant:
Direct sow seeds outdoors after the last frost date has passed and the soil temperature has reached at least 70F. Zinnias do not transplant well, so direct sowing is the preferred method. You can start seeds indoors 4-6 weeks before the last frost in cooler climates to get a jump start on the season, but be very careful not to disturb the roots when transplanting.

Location and Soil:
Choose a location that receives full sun (at least 6-8 hours of direct sunlight per day). Zinnias can tolerate a wide range of soil types but prefer well-draining, fertile soil. Amend heavy clay soils with compost to improve drainage. A soil pH between 6.0 and 7.0 is ideal.

Sowing Seeds:

Prepare the garden bed by loosening the soil to a depth of 6-8 inches and raking it smooth.

Sow seeds about 1/4 inch deep, spacing them 9-12 inches apart to allow for good air circulation and prevent powdery mildew.

Lightly cover the seeds with soil and gently water to moisten the seedbed.

Keep the soil consistently moist but not soggy until seedlings emerge, which typically takes 7-10 days.

Care and Maintenance:

Watering: Water at the base of the plant to keep foliage dry and prevent fungal diseases like powdery mildew. Water deeply once a week, or more frequently during hot, dry periods.

Fertilizing: While not heavy feeders, a balanced, all-purpose fertilizer can be applied once a month to encourage vigorous growth and abundant blooms.

Deadheading: To encourage continuous blooming, regularly deadhead (remove spent flowers). This redirects the plant's energy into producing new blooms rather than setting seed.

Pests and Diseases: Watch for common pests like aphids and spider mites. Good air circulation is key to preventing powdery mildew; avoid overhead watering.

Harvesting:
Harvest cut flowers in the morning after the dew has dried. Harvest when the flowers are fully open. The "wiggle test" can determine if a flower is ready: gently hold the stem about 8 inches below the flower and shake it. If the stem is floppy, it's not ready. If the stem is stiff, it's ready for cutting.