How to Winterize Chrysanthemums (Overwinter Mums)

So, you need to prepare your mums for the winter and get them ready for overwintering!

These flowering plants are a staple flowering perennial for any gardener looking to add some color to their yard.

Sadly, most people buy this plant or receive them as a gift only to see it wilt when winter comes.

Did you know they can go dormant over the winter and then come back next spring in full bloom?

No? Well this guide will teach you how to prepare your chrysanthemums for a chilly night!

Sound good? Let’s dive in.

Last updated: 11/10/21.

Chrysanthemum care guide

Plant type Flowering ornamental
Seasonality Perennial
Soil requirements Well draining, loamy
Soil pH 7.0
Sunlight Full sun, partial sun
Planting depth 6-8″
Plant spacing 16-25″
Watering frequency Top 6″ of soil moist
Fertilizer type 5-10-5 (NPK)
Colors Pink, purple, orange, white, blue, yellow, red
Bloom season Summer, fall
Hardiness zones 4-9
Beginner friendly? Yes
Scientific name Chrysanthemum x morifolium
Other names Gold flower, mums, chrystanths, Asteraceae
Fun fact Mums were first grown in China.

Can mums be winterized?

These gorgeous pink mums are ready for winter.
Mums are perennials, but a lot of newbie gardeners don’t know that.

Yes, it’s completely possible.

A lot of newbie gardeners buy this beautiful chrysanthemum for the fall only to see it shed those pretty flowers as winter comes.

But that’s not all there is to it.

After the winter, when properly winterized, mums will emerge again in the spring.

So yes, you don’t need to keep buying mums every year from the garden center. You can actually save those for next year.

Don’t waste your money.

How do you prepare garden mums for winter?

Some pretty chrysanthemums that are red and yellow.
These gorgeous mums are ready for winter.

Preparing chrysanthemum for the cold season is simple.

There are just a few things you should check over so you ensure that you’ll get the biggest blooms in the summer next year.

Mums are flowering plants that return every year (perennials).

They blossom during the summertime and will slowly drop their flowers when the cold time of year approaches.

You can ensure the best growth next season by deadheading your plant.

This means removing any flowers that remain on the chrysanthemum as the winter approaches.

Although this may seem scary to the newbie gardener, it helps encourage the best growth for the plant next year by conserving energy and not wasting it on flowers that’ll wilt anyway in the winter.

So don’t be afraid to deadhead your plant- this HELPS it as counterintuitive as it seems.

Remember: the chrysanthemum will turn color anyway. You’re just helping.

Use the right soil

Choosing the right soil is the “foundation” of a healthy plant.

As with other flowering ornamentals, you should go with well-draining soil. You may think it’s not a big deal, but oh it is.

Choosing the right soil that drains quickly will prevent frost buildup from any water that’s stuck in the soil- whether you plant mums in a container or the soil.

Use a high-quality soil that’s soft and well loamy.

Choose the right location

During the winter cold wind chills will blow against the plant.

Pick an area that protects them from high winds so they don’t get exposed to freezing chills during the night.

Consider placing them away from drafts, exterior walls, or areas with split currents.

Cutting back

Do you need to cut back mums?

Yes, you do. The plant will automatically die back during the winter months and you’ll see the leaves start to fall back.

Don’t just leave them there- you make them susceptible to mold and garden pests. Cut back the foliage that has died back and cut it off cleanly.

Cut the stems back to just 3-4” in length above the soil. You should only see bare stem left behind.

You can put markers so you don’t accidentally trample the plant.

New stems will sprout from these older stems. You’ll see it blooming into a new stem next year.

Don’t cut them too far back, because this may stunt growth next spring.

Leave it down to 8” at a minimum and you should be OK.

Use plenty of high-quality mulch

Using an organic, high-quality plant mulch will help protect your mums from the winter’s harsh frost when it needs it most.

There are dozens upon dozens of different mulch types out there on the market and choosing the right one can be a headache.

Stick with the basics- get some organic straw mulch and lay down about 3-6” around the stem.

Sprinkle it around and evenly distribute it. If you’re situated somewhere that has strong winds, you can add some rocks or foliage to help keep the mulch from blowing away.

Cover the base of the plant and all directions with a thick, even layer of organic mulch for best results.

This will act as an insulation barrier against cold weather when winter’s here.

You may have to replace the mulch occasionally if winds blow it away or if you have dogs that dig.

Keep the mulch on the soil until next season.

Don’t forget to use a garden spade and remove the mulch next season or else you’ll block the new plant sprouts from growing properly.

Use leaf coverage as a cold barrier

If you don’t have mulch, you can use leaf litter as a substitute.

Any leaf litter that’s clean and free of fungus and mold can be used in place of mulch.

Just place the leaves around the mum stem and this will keep it warm all winter.

You can even use the dead foliage from the plant itself as a natural insulation blanket.

Leaf mulch makes an excellent DIY mulch substitute.

Monitor the temperature

During the winter, you’ll want to check the weekly weather forecast.

If you see freezing temperatures coming, add some extra insulation for those nights.

Just be sure to remove it when the temperature starts to warm up again.

Do this on repeat throughout the winter to keep your chrysanthemums thriving.

These plants can tolerate temperatures as low as 20F.

When it drops below that, you’ll want to start taking measures to keep the plant protected from those chilly nights.

This is imperative to overwinter mums outdoors.

How do I protect my mums in the winter?

Orange mums.
Protecting them is easy.

You can protect your mums accordingly depending on your local hardiness zone.

If you’re in zones 4-7, where it gets very cold, you’ll have to mulch your plants if they’re planted in the soil or move them indoors if they’re potted.

These zones are cold enough to harm mums in the winter, so you’ll need to be extra careful.

If you’re in zones 8 and above, you may be able to get away with mild winters and not do anything.

As long as temperatures remain above 20F in the winter, you should be OK.

Just be sure to continually prune, water, and feed your mums and they’ll come back with huge blooms in the springtime.

For those random nights that are freezing cold, you can use a burlap wrap to cover your mums for winter.

Overwintering chrysanthemums in pots

Overwintering mums in pots.
Using a container makes it easier to protect, but it’s not ideal for these flowering plants.

 

If you have mums in plant containers, you’ll want to bring them inside during the cold.

This makes them especially easy to overwinter because there’s no dirt or soil to mess around with.

You can carry them into a temperature-stable area inside your home- preferable NOT in the garage as this can get just as cold as the outdoors depending on how well insulated your home is.

Regardless, just move the pots indoors and keep them in a stable area.

Did you know that mums planted in the earth do just fine in 20F weather, but potted ones don’t?

This is because the root system in potted mums are exposed since they’re above ground.

The roots are simply at the bottom of the planting containers you grew them in, so they’re exposed to the cold temperatures and are insulated by a thin 1” layer or so.

But the mums that grow in the soil are shielded by several inches of mulch and earth, so they’ll do fine in 20F temperatures.

This is why you need to take extra care with potted chrysanthemums during the winter.

Move them indoors and transplant them to larger containers if possible.

Use a pot with a hole that drains the water easily and prune it back.

Remove any wilted or spent flowers. The more you prune, the healthier the plant will be in the spring.

Don’t deadhead it if you’re growing it in a pot, but prune it at least to half the original size.

Storage

As mentioned earlier, store your planted mums in a temperature-stable area of your home.

Some common areas are unheated basements or sheds/outhouses.

Avoid using the garage if it’s too cold.

The target temperature range should be below 55F so that it gets some critical cold exposure, which is necessary for a healthy plant as in the case of peonies.

Don’t let the temperatures drop below 30F. You may have to use a plant cover if you can’t keep it within that range.

Remember that keeping your mum too hot or too cold both are detrimental.

You NEED cold exposure so it goes dormant, but you don’t want it too cold or else it’ll wither. It’s a balancing act.

Watering

Yes, mums need to be watered during the winter.

Keep the soil barely wet and don’t overdo it. There’s no magic to it. Just water when the soil starts to dry up but don’t soak the thing so that it’s sopping wet.

Only aim for about the first 2” of soil being wet- not the entire depth of the plant container.

Feeding

During the winter, you’ll have to care for the mums just like when they’re in season.

Use a high-quality fertilizer that’s phosphorus-based to feed the plant system over the winter until spring.

Keeping it warm

If temperatures are still too cold, you can use a plant blanket (burlap wrap).

You can also add mulch similar to how you’d keep an outdoor mum warm and cozy.

Put several inches of straw mulch on top of the soil to keep it stable. Remove when the climate starts to warm up.

Moving mums back to the outdoors

When spring rolls around again, you’ll start to notice the new sprouts coming out of the soil around the pot.

This is a sign that winter’s over and your mum is ready to be transplanted back outdoors.

Depending on how much of a temperature difference the outside is compared to where you were keeping it during the cold, you may have to slowly acclimate your plant to the new temperatures.

You can do this by placing it outside in partial sun and slowly giving it more time outside.

Start with ¼ of the day outside, then ½, then ¾, then a complete day outside. This will prevent any temp shock to your mum and eventually you can leave it outside in full sun.

Start to move the plant back outside and add some fertilizer and plant food. Use a high-quality fertilizer rated at 5-10-5.

Give your mum a good watering and prune away spent leaves. Your plant’s now ready for another season of blooms!

Other common FAQs about overwintering mums

Here are some other common questions gardeners tend to have about protecting their plants during the cold.

Should you deadhead mums?

Chrysanthemums should certainly be deadheaded before winter.

Most people will do this as part of their winter prep when they get the plants ready for lower temperatures.

Cut them back to just the stems at a minimum of 8” and you’re set.

Cutting back may seem painful, but deadheading them will help encourage new growth for next season.

You’ll end up with a healthier and larger bloom than if you just left it to wilt on its own.

Sometimes mums need a bit of help from their trusty owner (that’s you).

What are the mum hardiness zones?

Selecting the right cultivar for your area will help you make your life easier.

Why choose the wrong type and struggle to make it give you those signature blooms all summer long?

Most mums are perfect for zones 5-9, especially those hardier mums like Mammon Daisy Coral or Daisy Quill Yellow.

However, some mums grow well in the chills of zone 4, you just have to find the right one.

Do mums come back year after year?

Yes, mums come back every year because they’re perennials.

Mums are quite hardy and can handle the cold very well, but just not to freezing temperatures.

They’re considered a staple among many gardeners because of their colors and large blooms.

You often see a dome of color covering a plant- that’s when you know you have a chrysanthemum.

How do I get my mum’s back next year?

You can get your mums to come back next year by properly pruning it and cutting it back this winter.

As with most perennials, the flowers will wilt and fall off as the cold approaches. It’s your job to cut them off (known as cutting back) your plant.

This seems wrong, but it’s for your own good. The plant will come back stronger and larger than ever because it conserves its energy for the winter rather than wasting it on leaves and blooms.

It also helps add a stable root system to your plant.

To get it to come back next year, follow the steps in this guide:

  • Cut it back after fall
  • Mulch during the winter
  • Continually prune back leaves
  • Add water, fertilizer, and plant food if necessary
  • Remove mulch when spring comes around
  • Go full water, food, and fertilizer (5-10-5)

When should I trim my mums?

You should be trimming your mums throughout the entire season.

Don’t wait until the plant starts wilting completely before you deadhead it for winterizing.

Continually pruning plants and removing damaged foliage is a good practice. It helps prevent bugs, mold, plant viruses, and other nasty things.

Plus, it makes your mums look that much prettier.

After all, these flowering perennials only have one job: to make your garden beautiful.

So trim them when you think it’s necessary, but don’t deadhead until autumn’s over.

Can fall mums be planted outside?

Yes, but make sure you plant them at the right time.

Mums should be planted during the springtime ideally, because the fall may not build a usable root system to sustain themselves before the wintertime rolls around.

This is why planting during the fall is discouraged for chrysanthemums.

You should plant early in the spring so it has plenty of time to develop a strong support system and handle the freezing winter!

The reason behind this is because these plants spend their entire summer producing blooms rather than building strong roots.

And if you plant during this time, the plant isn’t in the best condition for rooting itself. It just spends day after day producing blooms for you rather than helping it sustain itself.

This is why you should avoid planting in the fall.

The best conditions are to use a large pot if you need to keep it contained.

Otherwise, plant it into the soil for best results

This just makes everything easier and less susceptible to cold damage. The soil protects the mums from cold much more efficiently than a pot will.

Additionally, if you have warmer winters (zones 8, 9, and 10) you can plant in early fall or summer.

However, I still suggest spring as the best time to plant your mums.

Is it ever it too late to cut back mums?

That depends. If you recently purchased a mum or received one as a gift, you’ll want to plant it into the soil ASAP.

However, if it’s already fall/autumn and winter is coming, you may just want to leave it in the pot and take it indoors to a chilly room.

That’s because if you try to plant mums in the fall, they don’t have sufficient roots to sustain themselves over the winter. So the chance of the chilly cold doing harm is greater.

For these, take them indoors and winterize in pots.

Cutting back should always be done before winter. Cut back to a maximum of 8”, depending on your hardiness zone.

Warmer regions can be more lenient.

Colder regions should be more strict. However, you should always cut back wilted foliage- do NOT leave this on the plant.

Can garden mums survive winter?

With the right layer of mulch, continual pruning, and some water, mums should do fine over the winter.

For those in a colder hardiness zone (zones 4 and 5), you may have to watch the weather and add some additional mulch or use a burlap wrap for freezing nights where the temperature dips below 20F.

However, for those in areas with milder winters, you should be OK with just some extra mulch to keep your mums warm.

With proper care, mums will enter dormancy over the cold season and come back in the spring.

There’s no need to buy new mums every single year. The same plant will sprout again next year. You just need to give it some TLC.

They can survive a winter freeze but will need some help from you.

Do you need to water mums during dormancy?

Yes, but very little. Just water enough to keep the top 2” of soil moist, but NOT wet.

Some people like to supplement with fertilizer or plant food, but this isn’t necessary unless you think your plant needs it.

Dormant plants still require a steady source of water, so don’t think that just because your chrysanthemum is dormant means it doesn’t need water. It does!

Further reading

Here are some handy references you may find useful:

Did you learn how to overwinter your mums?

You now have the basics of caring for mums over the winter.

These beautiful plants will show up against next spring with a dome of flowers waiting for you to enjoy all season long.

Just give them the right soil, add some mulch, cut them back, and give them some plant food/water during the cold season and you’ll be OK.

Do you have any questions? Have you done this before? Let us know using the comments section below!

Leave a Comment

Your email address will not be published. Required fields are marked *