When most flowers have given up for the season, hardy mums (Chrysanthemum morifolium) are just getting started with their vibrant display of colors. While technically considered a perennial, many gardeners treat fall mums as an annual using them as potted plants instead of landscape features. However, with the proper care, your mums can provide many seasons of colorful service in your landscaping. Here are 5 tips from local growers to help you convert your fall mums into perennial performers.
- Plant early
The biggest cause of hardy mums not surviving into the second season is getting them planted too late. To survive the first winter, your mums need time to develop a root structure that is deep enough to withstand the stresses of freezing and thawing in the soil. The sooner you get your mums planted, the better they will be.
- Plant correctly
One of the keys to a healthy start for your mums is getting them planted properly. This starts by selecting the proper location. Mums require at least 6 hours of direct sun per day and prefer full sun. They also like rich, well-drained soil that is slightly acidic to neutral. When you have selected the location, dig your hole twice the width and about 4” deeper than the pot size. Fill the bottom of the hole with potting soil or well-composted garden soil. Set the plant into the hole at the same depth it is in the pot then backfill with garden soil and compact moderately. Water immediately with a water-soluble plant food AND root stimulator. Apply a 3” layer of mulch.
- Fertilize early and often
Another key to successfully overwintering mums is root development. It can be hard for your plants to develop a strong root system while they are primarily focused on blooming. Using a slow-release granular fertilizer as a top dressing after planting can help, but the biggest boost you can provide is using a root stimulator at planting and again after two weeks. Depending on where you live and how early you get your mums planted, a third application at 4 weeks will help as well. Using a water-soluble fertilizer once per week when watering will also strengthen your plants and help to maintain the flowers longer.
- Water Frequently
As a general rule, mums like moist but well-drained soil. The key to strong mums throughout the fall is to water them before they show signs of stress or wilt. Depending on the weather, you may need to water your newly planted mums once a day. When you water, do not water down through the flowers and stems. Instead, apply water slowly at the base of the plant and allow it to soak into the soil.
Before the first hard freeze, you will need to completely mulch each mum plant. Wrap the plant with chicken wire or other “container” and fill the fence with leaves or straw. Your mulch should be twice the height and twice the width of the plant. When you think you have added enough, add a little more. DO NOT trim the mum plant in the fall. Instead, lightly pack your mulch throughout and around all the leaves and stems.
PRO TIP From Hershberger’s Farm and Bakery
To ensure your hardy mums survive the first winter, bring them inside. Store them in the coolest, darkest area in your house. This will allow the plants to go dormant without freezing. Plant the mums back into your landscape in early spring using the recommendations above to allow them a full growing season to become established.