The Story
Plant Bio
Chrysanthemum x morifolium 'Mammoth' is a bushy, perennial flowering plant characterized by its large, daisy-like flowers in various shades, and finely divided, dark green foliage.
This series is distinguished by its exceptional winter hardiness and its ability to form a large, shrub-like mound covered in flowers without pinching.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Perennial
Height
36 inches
Width
48 inches
Light
Full Sun, Partial Sun
Zones
4, 5, 6, 7, 8, 9
Water
Moderate
Humidity
Moderate
Lifespan
Perennial
Native To
Asia
Toxicity
Toxic to dogs, cats, and horses.
Bloom period
Autumn – Late fall
In flower about 2 months of the year
Planting
How to Grow
- Tuck seeds or cuttings into moist soil in early spring.
- Keep soil consistently moist but well-drained.
- Provide full sun for optimal flowering.
- Fertilize monthly during active growth for best blooms.
- Pinch back early growth to encourage bushier plants.
- Mulch around the base to retain moisture and suppress weeds.
Pro Tip
Use well-drained loamy soil and avoid overwatering to prevent root rot.
Keep It Thriving
Care Guide
Do
- Water regularly to keep soil moist 🌱
- Pinch back stems to promote bushiness
- Fertilize monthly during growing season
- Deadhead spent flowers for continuous bloom
Don't
- Overwater, which can cause root rot ❌
- Allow soil to dry out completely
- Neglect deadheading blooms
- Plant in heavy clay soil without amendment
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Divide | ||||||||||||
| Fertilize | ||||||||||||
| Spring Cleanup | ||||||||||||
| Winter Prep |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Multiply
Propagation Methods
Good to Know
Common Questions
Mammoth Chrysanthemum questions
What zones can Mammoth Chrysanthemum grow in?
Mammoth Chrysanthemum is hardy in USDA Zones 4–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Mammoth Chrysanthemum deer resistant?
Not reliably. Deer may browse Mammoth Chrysanthemum, especially tender spring growth — plan on repellents or fencing where pressure is high.
When does Mammoth Chrysanthemum bloom?
Mammoth Chrysanthemum typically blooms in autumn through late fall. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Mammoth Chrysanthemum need full sun?
Mammoth Chrysanthemum does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
More Chrysanthemum to compare

May Queen Shasta Daisy
Chrysanthemum leucanthemum 'May Queen'

Becky Shasta Daisy
Chrysanthemum leucanthemum 'Becky'

Christy Garden Mum
Chrysanthemum x hybrida 'Christy'

Small Wonder Chrysanthemum
Chrysanthemum x morifolium 'Small Wonder'

Mammoth Mum
Chrysanthemum x morifolium 'Mammoth Mum'

Chrysanthemum x morifolium Red
Chrysanthemum x morifolium 'Red'
Keep exploring
Explore the genus
Grow Mammoth Chrysanthemum 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.
















