The Story
Plant Bio
Collomia grandiflora, commonly known as the large-flowered collomia, is a native flowering plant that boasts vibrant yellow flowers and is attractive to pollinators.
Notable for its large, showy flowers that can attract various forms of wildlife, especially insects.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Annual
Height
24 inches
Width
12 inches
Light
Full Sun, Partial Sun
Zones
4, 5, 6, 7, 8, 9, 10
Water
Moderate
Humidity
Average
Lifespan
Annual
Native To
Western North America
Toxicity
Non-toxic
Bloom period
Late spring – Early summer
In flower about 2 months of the year
Planting
How to Grow
- Tuck seeds into well-draining soil in early spring.
- Mist cuttings lightly to maintain soil moisture during propagation.
- Ensure soil remains moist but not waterlogged during germination.
- Provide full sun for optimal growth, watering regularly in dry periods.
- Thin seedlings to prevent overcrowding, spacing 12 inches apart.
- Apply a balanced fertilizer monthly during the growing season.
Pro Tip
Sow seeds directly outdoors for best natural growth and vibrant blooms.
Keep It Thriving
Care Guide
Do
- Water regularly to keep soil evenly moist 🌱
- Deadhead spent flowers to encourage continuous blooming
- Mulch around plants to retain moisture and suppress weeds
Don't
- Avoid overwatering to prevent root rot ❌
- Don’t disturb roots when transplanting
- Refrain from fertilizing late in the season to prevent weak growth
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Harvest | ||||||||||||
| Plant |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Companion Plants
Multiply
Propagation Methods
Good to Know
Common Questions
Largeflower Collomia questions
What zones can Largeflower Collomia grow in?
Largeflower Collomia is hardy in USDA Zones 4–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Largeflower Collomia deer resistant?
Not reliably. Deer may browse Largeflower Collomia, especially tender spring growth — plan on repellents or fencing where pressure is high.
When does Largeflower Collomia bloom?
Largeflower Collomia typically blooms in late spring through early summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Largeflower Collomia need full sun?
Largeflower Collomia does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
Is Largeflower Collomia drought tolerant?
Yes — once established (usually after the first full season), Largeflower Collomia handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.
Keep exploring
Explore the genus
Grow Largeflower Collomia with confidence
See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.