The vibrant colors of fall are one of nature’s most beautiful shows – and nothing captures that seasonal magic quite like a blooming pot of chrysanthemums, also known as mums.
Their bold, fiery hues – gold, orange, burgundy, and rust – add an instant festive flair to porches, patios, and gardens as the air turns crisp and leaves begin to fall.
But if you’ve ever brought home a cheerful mum from a garden center only to watch it wilt and fade before it reaches full bloom, you’re not alone.
Many gardeners struggle to keep their fall mums alive – and blooming – long enough to enjoy the full season.
The truth? Mums can be a little tricky. They aren’t just “plant-and-forget” flowers.
Whether you’re growing them in containers or planting them in the ground, avoiding a few common mistakes can make the difference between a short-lived display and weeks of beautiful blooms.
Here are the top 7 mistakes people make when growing fall mums – and how to avoid them.
1. Not Knowing the Difference Between Garden Mums and Florist Mums
Not all mums are created equal. One of the biggest reasons mums don’t survive in the garden is because many people unknowingly plant the wrong kind.
There are two main types of chrysanthemums:
Florist mums (also called pot mums): These are bred for indoor decoration. You’ll often find them in grocery stores or as seasonal gift plants. They’re not bred to survive cold weather or outdoor planting. These mums are meant to look good for a few weeks and then be discarded.
Garden mums (hardy mums): These are the varieties you want if you’re hoping to enjoy blooms year after year. Hardy mums are bred for outdoor conditions and can survive winters in USDA Zones 5–9 – but only if planted early enough to establish roots before frost.
The mistake: Many people buy mums in full bloom in late fall and plant them outdoors, assuming they’ll come back in spring. But if those mums are florist types – or even if they’re hardy mums planted too late – they won’t survive the winter.
What to do instead: If you want mums as perennials, buy hardy varieties and plant them in late summer or early fall (6–8 weeks before the first frost). Give their roots time to settle and grow strong before winter hits.
2. Planting Mums in Too Much Shade
Mums love sunlight. They’re not shade-loving woodland flowers – they need full sun (at least 6 hours a day) to thrive and bloom profusely.
The mistake: Placing mums in areas with dappled or full shade, such as under trees or along shaded north-facing fences.
What to do instead: Choose the sunniest spot in your garden or balcony. If you live in a hot climate (Zones 8–9), afternoon shade is fine, especially in late summer, but morning and midday sun are essential for strong growth and vibrant flowers.
Bonus tip: Mums grown in sunnier areas tend to be bushier, bloom longer, and resist disease better than those in the shade.
3. Over-Fertilizing or Fertilizing at the Wrong Time
Feeding your mums is important – but when and how you do it matters just as much as what you feed them.
The mistake: Applying fertilizer after the plant starts to bud or is in full bloom. This can cause the plant to grow leggy, delay blooming, or even damage developing flowers.
What to do instead:
- In spring or early summer, use a balanced fertilizer (like 10-10-10) to encourage lush foliage and branching.
- Once buds start to form, stop fertilizing. At this stage, you want the plant to shift focus to flower production.
- In fall, high-phosphorus feed (like 5-10-10) can help encourage root development – but avoid high-nitrogen feeds.
Mums in containers may need more frequent, diluted feeding during their early growth stage, especially if the potting mix is fresh and nutrient-rich.
4. Inconsistent or Improper Watering
Mums may look tough, but they’re surprisingly picky about their watering needs. They don’t tolerate dry soil for long, but they also don’t like soggy roots.
The mistake: Letting the soil dry out too much or watering too frequently, leading to root rot.
What to do instead:
- Keep the soil evenly moist but not wet.
- Water at the base of the plant – not the leaves – to prevent disease.
- Check container mums daily in warm weather; they dry out quickly.
- Water when the top 1–2 inches of soil feel dry to the touch.
Mums planted in garden beds should be watered deeply 1–2 times a week during dry spells. In fall, reduce watering as the weather cools – but don’t stop completely until the ground freezes.
5. Cutting Mums Back Too Soon in Fall
Once mums finish blooming in fall, it’s tempting to clean them up right away by cutting them to the ground. But that could reduce their chances of returning in spring.
The mistake: Cutting back mums in fall, exposing the crown of the plant to harsh winter conditions.
What to do instead:
- Leave the foliage over winter. It acts as natural insulation, protecting the roots from freezing.
- In early spring, once new green growth appears at the base, cut the old stems back to 1–2 inches above the ground.
Also, apply a 2–4 inch layer of mulch (like straw, leaves, or bark) around the base in late fall to protect against winter kill – especially in colder regions.
6. Skipping Pinching During the Growing Season
Want your mums to be full, bushy, and covered in blooms? You’ll need to pinch them.
The mistake: Not pinching mums back in summer, which leads to tall, leggy plants with fewer flowers.
What to do instead:
- In early spring, when plants are about 6 inches tall, pinch off the top inch of each stem.
- Repeat the pinching every 2–3 weeks until early to mid-July (no later than mid-July to avoid delaying blooms).
Pinching encourages branching, which means more stems, more buds, and more flowers. Skip it, and you’ll likely end up with fewer blooms on a stretched, awkward-looking plant.
7. Neglecting Proper Drainage – Especially in Pots
Mums don’t like wet feet. Without proper drainage, their roots can rot fast, especially during cool, damp fall conditions.
The mistake: Using poorly draining soil or pots with no drainage holes.
What to do instead:
- Always plant mums in containers with drainage holes.
- Use a well-draining potting mix. Consider adding perlite or coarse sand to improve drainage.
- If planting in the ground, amend heavy clay soil with compost and sand to improve texture and prevent waterlogging.
If your mums are drooping and the soil feels soggy, root rot may already be setting in. Let the soil dry out slightly, prune back any mushy growth, and move the plant to a sunnier, drier location.
Even if you do everything right, not all fall mums will survive the winter – and that’s okay.
Modern mums bred for showy fall color often lack the hardiness of older varieties. Garden centers often sell mums as seasonal color – meant to be treated like annuals.
