Mammoth Yellow Quill Mum
Mammoth Yellow Quill Mum
A University of Minnesota Hardy Mum That Comes Back Every Year
Mammoth Yellow Quill Mum (Chrysanthemum 'Mammoth Yellow Quill') is part of the legendary Mammoth series bred by the University of Minnesota specifically for our brutal winters — a true perennial garden mum that returns and grows larger each year, unlike the throwaway florist mums sold every fall. It builds into a dome up to 3 to 4 feet wide, smothered in cheerful quilled-petal yellow blooms in fall. Cold-hardy to zone 3, deer-resistant, and pollinator-friendly, it's a Minnesota-bred staple for sunny borders in Edina, Woodbury, and Maple Grove.
Mammoth Yellow Quill Mum Plant Details
| Attribute | Detail |
|---|---|
| Botanical Name | Chrysanthemum 'Mammoth Yellow Quill' |
| Mature Size | 24–36 in. tall, 36–48 in. wide |
| Hardiness Zone | 3–9 (Twin Cities is zone 4b–5a — fully hardy; bred by the U of M for cold climates) |
| Light | Full sun (6+ hours) |
| Bloom Time | Late summer into fall |
| Flower Color | Yellow, quilled petals |
| Soil | Well-drained; tolerates clay; prefers good drainage over winter |
| Winter Hardiness | Reliable to zone 3 — a true returning perennial mum |
| Deer Resistance | Usually avoided by deer |
Landscape Uses in Minnesota
Fall-color anchor: Its huge cushion form gives a shrub-like mound of fall color — use it as a specimen or in a row. Space 3–4 feet apart for full size.
Pollinator and cut-flower gardens: Late bees and butterflies work the flowers, and the blooms are great for fall bouquets. Pair with asters, ornamental grasses, and sedum.
Best Time to Plant in Minnesota
Spring (late April–May) is strongly preferred so the plant has the full season to establish deep roots before winter — this is the key to hardy mum survival. Avoid fall planting; fall-planted mums often fail to overwinter.
How to Plant Mammoth Yellow Quill Mum
Dig a hole twice the root ball width at the same depth, mixing in compost. Set the crown level, backfill, water well, and mulch 2–3 inches deep. Space 3–4 feet apart. Pinch the tips once or twice in early summer for a denser, more floriferous dome.
Watering Mammoth Yellow Quill Mum
First year: Water every 2–3 days at first, then weekly through the season to build a strong root system. Stop 2–3 weeks before the ground freezes.
After year one: Water during dry spells; established plants are fairly drought-tolerant. Leave the dead stems standing over winter for crown protection and cut back in spring.
Q: Is this different from the mums sold at stores in fall?
Yes — this is a U of M-bred hardy perennial mum that overwinters and grows bigger each year, unlike florist mums, which are usually not winter-hardy here.
Q: Why plant in spring instead of fall?
Spring planting gives the roots a full season to establish, which is essential for surviving Minnesota winters. Fall-planted mums often don't make it.
Q: Will it survive a Minnesota winter?
Yes — bred specifically by the University of Minnesota for zone 3–4 winters, with good drainage.
Q: Should I pinch it?
Pinch the growing tips once or twice before early July for a fuller, more flower-packed dome.
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Aster: A classic fall pollinator partner.
Little Bluestem (Schizachyrium): A native grass for fall texture.