Zinnia
Seed # 151
Basic Information
- Seed Number
- 151
- Seed Name
- Zinnia
- Variety
- California Giant
- Category
- Flower
- Plant Family
- Asteraceae
- Plant Type
- Giant-flowered zinnia (Zinnia elegans)
- Planting Method
- Direct Sow or Transplant
- Seed Status
- In Seed Bank
- Created
- 2026-08-14 00:50:34
- Updated
- 2026-08-19 15:35:29
Planting Information
- Start Planting Date
- Apr 7
- Last Recommended Planting Date
- Jul 15
- Plantable Months
- April, May, June, July
- Indoor Start
- Apr 7 – Apr 14
- Direct Sow
- May 6 – Jul 15
- Transplant
- May 12 – Jun 15
- Indoor Start Weeks Before Frost
- 4 weeks
- Transplant Weeks After Frost
- 1 weeks
- Germination Days
- 3–7 days
- Harvest/Maturity
- Not recorded
- Succession Planting
- 14 days
Growing Conditions
- Ideal Soil Temperature
- 70-85°F
- Planting Depth
- 1/4 in
- Plant Spacing
- 12-18 in
- Row Spacing
- 18-24 in
- Thin-To Spacing
- 12-18 in
- Sun Requirements
- Full sun
- Water Needs
- Moderate water; irrigate at the soil line and avoid prolonged wet foliage
- Soil Preference
- Rich, well-drained soil with good air circulation
- Minimum Container Size
- 3-5 gal
- Plant Height
- 3-4 ft
- Perennial/Biennial Status
- Annual
- Container Friendly
- Yes
- Trellis/Support Needed
- No
- Frost Tolerant
- No
- Heat Tolerant
- Yes
- Drought Tolerant
- Yes
- Pollinator Friendly
- Yes
- Medicinal
- No
Garden Uses
Container Cut Flower Pollinator Seed SavingCompanion Planting
| Plant | Relationship | Notes |
|---|---|---|
| Basil | Good Companion | Not recorded |
| Basil | Good Companion | Not recorded |
| Basil | Good Companion | Not recorded |
| Dill | Good Companion | Not recorded |
| Marigold | Good Companion | Not recorded |
| Marigold | Good Companion | Not recorded |
| Marigold | Good Companion | Not recorded |
| Marigold | Good Companion | Not recorded |
Storage
- Seed Source/Brand
- Ferry-Morse; MSU Extension; UMN Extension mildew
- Packet Year
- Not recorded
- Quantity Notes
- Not recorded
- Purchase Date
- Not recorded
- Expiration Year
- Not recorded
- Storage Box
- Not recorded
- Container
- Not recorded
- Envelope
- Not recorded
- Row
- Not recorded
- Slot
- Not recorded
- Storage Notes
- Not recorded
Notes
Original Planting Method: Direct sow after frost, or start indoors 2–4 weeks early. Zinnias grow quickly and do not need a long indoor start.
Original Start Planting Date: Apr 10 – Apr 25 indoors; ~May 15 direct outdoors
Original Last Suggested Planting Date: ~Jul 20
Outdoor / Direct Sow / Transplant Window: Direct sow/transplant ~May 15 – Jul 20.
Days to Harvest / Bloom: ~35–75 days to bloom; fuller flowering often ~60–75 days
Container Friendly: Yes; ~18+ in container; plants can become tall
Pollinator Friendly: Yes; excellent for bees and butterflies
Medicinal / Herbal Use: Ornamental/cut flower
Succession / Reusable Notes: Sow every 2–3 weeks through early/mid-Jul for fresh blooms. Deadhead/cut often. Saved seed may cross with nearby zinnias.
Zone 6B Notes: Plant after frost and once soil warms. Zone 6B has enough season for multiple sowings; fall frost ends the plants.
Companion Plants: Dill, basil, cosmos, marigolds, vegetables, other flowers that benefit from pollinators
Avoid Planting Near / Watch Outs: Avoid crowding and frequent overhead watering. Watch for powdery mildew and leaf spot. Frost kills plants.
Sources: Ferry-Morse: https://ferrymorse.com/products/zinnia-california-giants-mixed-colors | MSU Extension: https://www.canr.msu.edu/news/growing_zinnias_in_your_flower_garden | UMN Extension mildew: https://extension.umn.edu/plant-diseases/powdery-mildew-flower-garden
[[RESEARCH ENRICHMENT START]]
Zone 6B: Direct sow after May 5 or start indoors approximately 4 weeks before transplanting. Succession sow through mid-July for continued flowers until frost.
Germination: Warm soil produces rapid germination, typically within about 3-7 days.
Harvest: Harvest fully open flowers once stems are rigid enough to pass the wiggle test.
Seed Saving: California Giant is an open-pollinated zinnia type, but it crosses readily with other Zinnia elegans cultivars. Isolate for true seed.
Special Care: California Giant is traditionally a tall, large-flowered strain. Provide good airflow to reduce powdery mildew and pinch young plants for more branching if desired.
Research Source: Baker Creek Heirloom Seeds — https://www.rareseeds.com/store/plants-seeds/flowers/zinnia-seeds — Zinnia elegans giant-flowered heirloom types and general zinnia classification
Research Source: Johnny's Selected Seeds — https://www.johnnyseeds.com/flowers/zinnias/ — giant zinnia cut-flower use and general zinnia production
[[RESEARCH ENRICHMENT END]]