If you are looking for a great way to save money and add perennial beauty to your landscape – then taking the time to overwinter your mums is a great place to start!
Mums are one of the first plants gardeners turn to for fall color, and it is easy to see why. These durable plants flower for weeks on end, and look incredible in pots, containers and baskets,
But they can also be amazing when planted in the landscape. Even better, most mum varieties are more than tough enough to withstand the cold of winter, coming back to provide gorgeous autumn color year after year.
A Look At Hardy Mums
Although many folks consider mums (chrysanthemums) to be an autumn flowering annual, the majority of varieties for sale are actually quite hardy. Because of this, with just a bit of extra care, they can be grown quite easily as a perennial.
It is important to note that not all mums can be overwintered and kept from year to year. There are actually two distinct types of mums, hardy and floral. In short, hardy mums can be kept, while floral mums cannot be saved.
The difference between the two is mainly in their roots. Floral mums have very shallow roots. Because of this, they simply can’t stand up to the rigors of wintertime when planted outside. The shallow roots quickly freeze, and the plant dies off in the process.
Hardy mums on the other hand have a much deeper root system. Hardy mums, often referred to as garden mums, can survive the perils of winter more easily.
In fact, hardy mums can usually overwinter successfully all the way in to Growing Zone 5. Especially when just a little extra attention is given in late fall to help protect them through winter.
Selecting The Right Mums To Save
With all of that said, if you want to overwinter and save your mums, start by making sure to purchase hardy or garden mums, and not the floral mum variety.
Most nurseries and garden centers will have plants clearly marked. If not, as a rule of thumb, plants with smaller, more compact foliage and tightly wound blooms tend to be floral. Mums with larger stems, foliage and blooms are most likely hardy.
Initial Fall Care – How To Overwinter Mums
Mums that are purchased in the fall need special protection to make it through their first winter. Leaving first year pots outdoors, even when they are labeled as “hardy” will most likely result in a deceased plant come next spring.
Although mums can be taken out of their pots for planting directly into the landscape in late fall, for first year plants, it usually will results in plant failure. Even with a heavy mulching, plants simply can’t survive.
Unfortunately, by planting in late autumn, the mums simply don’t have enough time to establish firm roots in the soil. Because of this, the constant thawing and freezing will take its toll.
Bringing Plants Indoors – How To Overwinter Mums
For first year plants, the best method for success is to overwinter your mums indoors. It is extremely important to bring your mums inside before the first freeze occurs. As they sit in a pot or container, a single hard freeze can be enough to kill off the roots.
Before bringing your mum indoors, first remove all of the spent blooms and flowering blooms that might be remaining. Not only can they create a mess indoors as they fall off, this also helps the plant conserve energy for next year. A quick clipping with a good pair of hedge shears will make fast work of cutting off the blooms.
When bringing indoors, select a cool location that receives little light. A cool, dark basement or garage works great for this purpose. If not available, select the coolest, darkest room of the house.
By bringing the plant indoors, it allows the mum to go dormant, but not risk freezing out. And then as spring rolls around, you can safely plant the mums into the landscape.
Planting Mums In The Spring – How To Overwinter Mums
The following spring, as soon as soil warms and the threat of a hard freeze is over, it is safe to plant in the landscape. Mums perform best in fertile, well-drained soil. When planting, add in a bit of compost to help their root systems establish quickly.
You can also replant into a container or pot as well. If you do, you will need to re-pot with fresh soil and most likely move to a larger vessel. This will accommodate the extra root growth that will occur over the summer.
Once planted, cut the stems and foliage back to just above the soil line. Within a few weeks, you should start to see new growth emerging.
Left to grow on their own, mums will normally bloom in mid to late summer. With this in mind, if you are looking for brilliant fall color, you will need to cut them back a few times before they bloom early.
Pinching back is the “official” term of this process, which is simply cutting the plant to within a few inches of height. For most plants, trimming back in early July and again in August works best. This allows the new growth to grow in a more compact fashion. It also means a fuller fall blooming cycle.
Subsequent Care – How To Overwinter Mums
In the fall of the second year and beyond, for mums planted directly into the landscape, there is no need to bring them indoors. The roots of these plants are now firmly established and can handle the winter with a bit of extra protection.
Unlike cutting back other perennials, it is best to leave the mums foliage in tact through the winter. This helps give it a bit of extra protection from winter’s cold and harsh winds.
In addition to leaving the foliage, apply a few inches of straw, leaves or mulch to the base of the plant. This helps insulate the roots from extreme cold, and from constant thawing and freezing. In the spring, cut back the foliage to allow the plant to spring forth new growth.
Just as with the previous year, you will once again need to cut back the growth in July and early August to force fall blooms. If you re-pot your mums, you will once again need to bring them in over the winter for protection.
With a few years growth, your mums may reach a size where splitting is necessary. Spring is the best time for this chore, as it allows the plant to re-establish roots throughout the summer. Splitting not only keeps plants healthy and blooming strong, it is also an excellent way to double your plants for free.
Here is to overwintering your mums this fall, and to having lasting autumn color in your landscape year after year.
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