Zinnia Giants of California
Zinnia Giants of California
Couldn't load pickup availability
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 and substance, these plants produce massive, semi-double to fully double flowers—up to 12cm (nearly 5 inches!) across—on tall, sturdy stems. The flat, overlapping petals create perfect, almost geometric blooms in a vibrant fiesta of hot colours: cherry red, bright orange, canary yellow, deep violet, hot pink, and coral.
These are the undisputed kings of the cutting patch. Just a few stems fill a vase with bold, architectural colour that lasts for 7-10 days. They are heat-loving, sun-worshipping plants that actually get better and better as the summer gets hotter, flowering more prolifically as temperatures rise. They bloom tirelessly from mid-summer right through to the first killing frost, providing months of non-stop cutting material.
Read More
🌿 Understanding the Plant
Zinnia elegans 'Giants of California' is a Half-Hardy Annual (H2). Originating from Mexico, it thrives in hot, dry conditions with intense sunshine. In the UK, it is the ultimate "summer performer," truly coming into its own from July until the first sharp frosts of autumn.
The "Heat-Worshipper" Rule: Zinnias absolutely detest cold and wet conditions. They will "sulk"—turning yellow and refusing to grow—if planted out too early into chilly UK soil. Success depends on waiting for the genuine warmth of June.
Wildlife Champion: These giants are a major draw for butterflies and bees. Their large, flat-petalled landing platforms and rich nectar supply make them a high-energy feeding station during the peak of summer.
🌱 Growing Guide
Zinnias grow rapidly once the weather warms up, but they require a gentle hand during establishment.
How to Sow:
Option 1 - Indoor Sowing (Best): Sow into module trays or individual pots from mid-April to mid-May to minimise root disturbance. Sow 5mm deep and keep warm at 20°C; they germinate quickly in 5-10 days. Option 2 - Direct Sow: Sow directly into prepared beds in June once the soil is warm.
Where to Plant:
Plant out in early June in a sheltered, full sun position. They require rich, fertile, free-draining soil. Because they reach up to 100cm, they benefit from support—run horizontal twine between stakes to create a supportive grid.
Ongoing Care:
Pinching: When plants are 15cm tall, pinch out the central growing tip to encourage branching and more flower heads. Watering: Always water at the base of the plant. Wet foliage encourages powdery mildew, which Zinnias are susceptible to in humid UK weather. Feed every two weeks with a liquid tomato fertiliser once they start to bloom.
📋 Plant Specifications
| Botanical Name | Zinnia elegans 'Giants of California' |
| Common Name | Giant Zinnia / Youth-and-Age |
| Plant Type | Half-Hardy Annual |
| Hardiness | H2 (Needs frost protection) |
| Light Requirements | Full Sun ☀️ (Essential) |
| Height | 90cm - 100cm (Tall florist type) |
| Spread | 45cm |
| Spacing | Plant 30cm apart |
| Flowering Period | July to October/November |
| Perfect For | ✂️ Premier Cut Flower 🦋 Butterfly Magnet 🔥 Hot Colour Schemes 🏗️ Architectural Structure |
| Seeds per Packet | Approximately 100 seeds |
🤝 Beautiful Garden Combinations
The bold, rigid forms of these giant Zinnias create high-impact displays when paired with contrasting textures :
- ☁️ Ageratum 'Timeless Mix': The Texture Masterclass. The bold, waxy petals of the Zinnia contrast beautifully with the soft, fuzzy "powder puffs" of Ageratum, creating a sophisticated, multi-dimensional border.
- 🏮 Amaranthus 'Love-Lies-Bleeding': The Tropical Clash. The tall, upright Zinnia heads paired with the cascading, rope-like tassels of Amaranthus create a high-energy, exotic look perfect for late summer.
📅 Sowing & Flowering Calendar
Sow indoors in spring or direct sow in June. Flowers from midsummer to the first frosts.
| Month | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sow Indoors | ✓ | ✓ | ||||||||||
| Plant Out | ✓ | |||||||||||
| Flowering | ✓ | ✓ | ✓ | ✓ | ✓ |
🦋 Butterfly Magnet
Zinnias are widely considered one of the best annuals for attracting butterflies. The huge, flat-topped blooms of 'Giants of California' act as stable landing pads, allowing butterflies to feed easily in the heat of a summer afternoon.
📖 Want more detailed growing advice?
View our Complete Growing Guide for Zinnias →
