When is the Finest Time to Plant Fall Mums?

Chrysanthemums, or mums, are one of the most popular flowering plants for the fall garden. Mums are readily available, beautiful, and hardy and provide long-lasting, late-season color to your home and garden. Great for beginners, growing mums is both easy and rewarding!

Many colorways stand out, including white, yellow, orange, brown, pink, and purple. Hundreds of cultivars exist with countless combinations of flower colors, sizes, and flower types. Their long-lasting, showy flowers are a highlight in many fall gardens and autumn-themed displays. 

Many gardeners grow mums as annuals and discard them after the first frost. You can maximize your enjoyment of these plants by keeping your mums through the winter and allowing them to return the following year and many years after for repeat blooms.

Keep reading as we dig deeper into how to plant and grow these spectacular fall flowers.

The Short Answer

The best time to plant fall mums is in the fall, at least six weeks before your average first frost. Depending on your location, you should be planting anywhere from late August through mid-October. Planting well before the first frost will allow your plants to develop some healthy roots and start establishing in the location where they will spend the winter. You can also plant mums in the spring and maintain them in your garden throughout the summer so they will be fully blooming by fall.

The Long Answer

Timing

Understand your frost dates and plant hardy mums at suggested times for your zone.

To know when to plant fall mums, know your frost dates. Hardy mums are perennials in USDA hardiness zones 5 through 9.

In much of zone 5, the average first frost date is in mid-October, and in portions of zone 9, it is late November through mid-December. Everyone’s first frost date is unique to their particular region, but to give a general idea, you can use the following suggested planting times.

Give your mums at least six weeks to adjust to their new location before the first frost. Mums become widely available in the fall. If you buy your plants late in the season, it may not be too late to plant them.

To grow them in a container other than the one they came in, transplant them into a container, raised bed, or garden plot as soon as possible. There’s still a good chance they’ll survive the winter, especially in milder climate zones.

If you purchase mums in the spring, you can transplant them immediately. This is an excellent season for establishing perennial flowers in your garden. Summer transplants may be more challenging because of the intense heat and sunlight that creates unnecessary stress for your plants.

Types of Mums

Mums, originating from Asia, are versatile garden plants with numerous species and cultivars.

Mums are fast-growing, clump-forming plants that are members of the aster family. They originated in Asia and have become widespread and extremely popular garden plants. Over 20 species of Chrysanthemum and hundreds of different cultivars are available for the adventurous gardener. These are most commonly sold in the autumn months near their peak bloom season. 

Some mums will stay very small and compact, never growing more than 12 inches tall. Others will grow up to 3 or 4 feet tall or may have more sprawling tendencies. Most garden mums you encounter will be winter hardy and can be grown as perennials in zones 5 through 9. 

They will bloom anywhere from mid-summer through the first frost, depending on the variety and how you manage them.

One nice thing about mums is that they don’t grow aggressively or take over your flower garden. Some hardy chrysanthemum varieties will slowly spread over time, but the most popular garden mums sold in the autumn will stay quite compact.

Mum cultivars are often identified by their colors and flower type, such as spider, pompon, quill, anemone, or single blooms. The different species of chrysanthemum have different places of origin, but most plants available to consumers are cultivars.

Growing Conditions

Light

Mums need 6 to 8 hours of direct sunlight daily for optimal performance.

Mums will perform best in full sun, with at least 6 to 8 hours of direct sunlight per day. They will tolerate partial shade but won’t stay as compact or bloom as well as those grown in full sun.

Soil

Use nutrient-rich, well-drained soil and enhance with organic compost at planting.

The soil should be nutrient-rich and well-drained. Add some organic compost at planting time to help enrich the soil and get your plants off to a great start.

If you are growing mums in a container or raised bed, use a high-quality potting mix or raised bed garden soil. This should be loose, well-drained, and high in organic matter.

Water

Maintain steady soil moisture, not overly wet.

Mums prefer consistent soil moisture so the roots stay moist but not wet or soggy. Give your plants about 1 to 2 inches of water each week. If you’re growing them in pots, check them daily during the warmest days to ensure they stay moist. Potted mums dry out very quickly.

How to Plant Mums

Transplant potted chrysanthemums in your garden on a cool, overcast day, providing good air circulation.

It’s simple to plant fall mums in your home garden. Assuming you bought potted nursery-grown plants, you need to transplant these into your garden.

Do your transplanting on a cool, overcast day to help minimize stress on the plant. Most varieties of mums should be planted 18 to 36 inches apart, allowing plenty of space and good air circulation between plants.

Use a garden spade or small trowel to prepare a hole slightly larger than the pot your plant is currently growing in. Use this opportunity to add some organic compost to the soil, giving it a nutritious boost for your plant.

Carefully remove your mum from its pot and transfer it into the hole. Refill the gaps around the edges with soil and gently tamp it down. Give your newly transplanted mums a big drink of water to help them settle into their new location. 

Mulch

For healthy mums, keep shallow roots damp and add mulch to retain soil moisture.

Mums have a shallow root system and like their roots to be kept moist. Use any organic, biodegradable mulch that helps protect the roots, retains moisture, and enriches the soil as it breaks down. Use compost, peat, or leaf mulch for the best results.

In the winter, add a 4 to 6-inch layer of mulch around your plants to help protect them from the cold and insulate the roots from harsh temperature changes. In the spring, you’ll want to remove some of the mulch and keep a 2 to 3-inch layer of mulch around your plants.

Annual Maintenance

Fertilizer

As new leaves emerge, apply general-purpose fertilizer in spring to promote healthy root growth.

Add some general-purpose fertilizer each spring when your mums are beginning to grow new leaves. This helps them develop a healthier root system and prepare for an abundant fall bloom.

Pruning

Deadhead mums to encourage new blooms.

When should you prune your fall mums? There are two times: fall deadheading and winter pruning. Use sharp, clean garden pruners to deadhead spent flowers in the fall to keep your plants looking their best. This removes the dead flowerheads and encourages your plant to produce more flower buds. 

Do not prune your plant immediately after the first frost. Allow it to overwinter without pruning it first. In late winter or early spring before new leaf buds form, prune your plants low to encourage fresh, dense new growth in the spring.

Pinching

To enhance mums’ growth and fall bloom, pinch off early flower buds until mid-July.

Pinching is a common technique recommended for mums. Pinch off early flower buds until early to mid-July. This helps your plants develop more branches and become fuller.

It also encourages them to wait until fall to flower, and you will have a massive fall blooming season. Without pinching off the early flower buds, your plants will produce fewer flowers and longer flowerless stems. 

Weeding

Prevent competition by maintaining a weed-free garden to ensure optimal growing conditions for your mums.

Mums don’t want to compete with weeds for light, water, or space. Keep your flower garden weeded to reduce weedy competition and provide your special flowering plants with the best growing conditions possible.

Frequently Asked Questions

Yes, absolutely! Mums look great in containers and are an ideal plant for raised bed gardening. They can be grown in any sunny location with moist soil and good soil drainage. If you are transplanting mums into a decorative gardening container, check first to make sure your container has good drainage holes. If not, you’ll want to create drainage holes before planting. Mums do not like to sit in soggy soil.

You could dedicate an entire raised bed to mums, or mix them with some other complimentary flowers like cosmos, or beautiful fall vegetables like blue kale, to add some interesting variety. Just be sure to keep the soil moist, especially if you are growing your mums in smaller pots or containers because their roots will dry more quickly in smaller containers.

There’s always a hope that you can save a mum through the winter, even if you didn’t plant it before the first frost. Consider overwintering a potted mum in a cool, dark location like a garage. If you are overwintering it in a pot, don’t let it freeze, but keep it cool so the plant will stay dormant. You’ll also want to keep the soil very slightly moist so it doesn’t dry out completely. In the early spring, you can prune it to a few inches tall and transplant it outside in your garden and watch it grow.

You can still try planting it outside, even after the frost. Cover it with a thick 4 to 6-inch layer of mulch. In early spring, before new growth starts, prune your mums to a few inches tall, remove a couple of inches of the thick mulch and with any luck, your plant will have survived the winter. As the weather warms, you should see some fresh new leaf buds starting to grow.

That depends a lot on the cultivar you have. Some of the showiest varieties of mums do not attract any pollinators because the flowers are so complex that insects can’t reach the pollen. A simple flowered variety, such as Hillside Sheffield Pink, has showy flowers and the most easily accessible pollen that will attract a great number of pollinators.

Final Thoughts

If you love cheerful colors, consider buying and planting fall mums for your yard. While mums are excellent seasonal potted plants, growing these beauties in your yard year-round is more rewarding. Plant fall mums in the late summer or early fall to enjoy them in your yard this season and for many years. With a small amount of annual maintenance, you can have reliable repeat bloomers to add life and color to your landscape throughout the growing season.