Zinnia - 'California Giants'

Overview

Zinnias are one of the easiest flowers to grow, shooting up quickly and blooming heavily. Zinnia flowers can create a massive burst of color in your garden, and they attract beneficial insects to your garden such as butterflies. 

Conditions

Zinnias prefer fertile, well-draining soil that is rich in organic matter. Consider adding compost before planting to amend the soil. For optimal blooms and large plants, provide full sun (6+ hours of direct sunlight per day).

Planting

Zinnias are most commonly started indoors and transplanted into the garden. Use our grow calendar tool to find specific planting dates for your region! Seeds germinate quickly in 3-10 days.

Plant seeds indoors in starter pots or trays 4 weeks before your desired transplant date. Plant ¼" deep and keep the soil surface moist until emergence. Do not allow plants to become root bound, as zinnias are sensitive to transplant shock. Transition outside (harden) for 7 days before outdoor transplant. Space 9-12" apart for most varieties. 

In warmer climates, zinnia seeds can be directly planted outdoors in the garden. When the soil is warm, plant 6 seeds per foot, 1/4" deep. Cover lightly but firmly. Keep surface from drying out until emergence. Thin to 9-12" apart after the first true leaves appear.

Pests and Disease

Adequate spacing is important to keep proper air circulation and prevent powdery mildew.

Care & Harvest

It is necessary to cut and remove old flowers (a process called deadheading) to encourage new flower growth. Zinnias can be left in the garden through blooming or cut for flower arrangements shortly before flowers are completely open.