Zinnia 'Giants of California' Seeds

If you want flowers that look like Dahlias but grow as easily as daisies, 'Giants of California' is the variety for you. Bred specifically for size, these plants produce massive, semi-double to double flowers (up to 12cm across) on tall, sturdy stems. The flat, overlapping petals come in a vibrant fiesta of colours: cherry red, bright orange, canary yellow, violet, and pink.

These are the kings of the cutting patch. Just a few stems fill a vase with bold, architectural colour. They are heat-loving, sun-worshipping plants that get better and better as the summer gets hotter, flowering tirelessly until the first frost.

Why Your Garden Needs 'Giants of California'

We love this plant for its "vase value." Zinnia stems are hollow but stiff, meaning they don't flop in arrangements. They have an incredible vase life, often lasting 7-10 days in water. This variety has been bred with longer stems specifically for floristry.

It is also a top-tier butterfly plant. The large, flat flower heads act as stable landing pads for larger butterflies like Peacocks and Red Admirals, allowing them to feed on the nectar-rich centre with ease.

Understanding the Plant: What is a Half-Hardy Annual?

Zinnia is a Half-Hardy Annual.

It originates from Mexico, so it loves heat and hates the cold.
The Golden Rule: Do not rush to sow! Zinnias dislike cold, wet soil. If you sow them too early, they will sulk. Wait until late spring (April/May) to sow, and only plant out when the nights are warm (June).
Top Tip: Pinch them! When the young plants are about 20cm tall, pinch out the central growing tip. It feels scary to snap the top off, but this forces the plant to branch out, giving you triple the amount of flowers.

Growing Guide: How to Sow and Grow

Zinnias grow very fast but resent root disturbance.

🌱 Germination:
Sow indoors in April/May or direct sow in late May/June. Sow 5mm deep. Keep warm (20°C). Germination is rapid, usually 5-10 days. If sowing indoors, use module trays to minimise root disturbance when transplanting.

Where to Sow:
They demand full sun and a sheltered spot. They need rich, fertile soil to fuel those giant flowers. If growing in containers, use a large pot and keep them well-fed.

Care While Growing:
Watering Rule: Always water at the base of the plant, avoiding the leaves. Wet leaves can lead to mildew.
Support: These "Giants" grow up to 1 metre tall. In a windy garden, they will need a stake or netting to keep them upright.

Plant Specifications

Here is a quick reference guide to the key features.

My Recommended Garden Companions

Zinnias are bold and stiff, so they need softer, airier partners to create a balanced bouquet look:

• ❄️ Ammi Majus (Queen Anne's Lace): The florist's essential. The flat, white lacy heads of Ammi break up the bold, blocky colours of the Zinnia. Growing them together creates a ready-made arrangement in the border.
• ☁️ Cosmos 'Purity': Soften the look. Zinnias can look quite rigid. Planting feathery white Cosmos nearby adds movement and softness, and both plants thrive in the exact same sunny conditions.

📅 Sowing & Flowering Calendar

Sow indoors in spring. Plant out only when warm. Flowers mid-summer to frost.

(↔️ Swipe chart to see all months)