Chrysanthemums shine in late summer and fall, brightening the display as other blooms fade. They appear with a splash in jewel tones of the season, from garnet and gold to purple and pink.

Hundreds of varieties bring different forms, colors, flower shapes, and bloom times. Spanning the summer-to-fall transition, they support pollinators and beneficial insects heading into the cool season.

To top it off, garden mums are one of the easiest perennials to grow. Their foliage is attractive throughout the growing season, dense and deep green with lobed leaves, leading to the fall show. We may purchase florist mums as autumnal decor for porches and patios, but their impact in the garden goes much further.

With transplanting to the right site, garden mums grow year-round in the ground or in pots and containers. They offer extended interest with their profusion of late blooms and make showy cut flowers. Here, you’ll learn where to plant mums for a spectacular display season after season.

Mum Overview

Varied petal shapes create endless visual garden interest.

Chrysanthemums are clumping perennials hardy in USDA zones 5-9, with some hybrids overwintering in zone 4. They feature distinct flower forms and petal arrangements that include pom pom, spider, cushion, anemone, decorative, and more. They bloom in sprays with a multitude of blooms or as large-flowered selections with showy, single flowers per stem. 

Mums have a long garden history, first as a culinary herb cultivated in China as many as 2000 years ago. In Japan, they became the Emperor’s emblem of the highest honor service. The gems gained popularity in Europe in the 17th century and the Americas in the late 1700s for their ornamental value and versatility as perennials and decorative cut flowers.

The genus belongs to the daisy family (Asteraceae), and there are about 20 species of garden mums. They have upright, woody stems and soft new growth. Underground shoots, or stolons, increase their ability to survive over the winter.

Florist mums (the potted specimens we buy in the fall, or as cut flowers) are often less hardy due to fewer stolons. If keeping potted mums, overwinter them indoors and plant them out in the spring. These tend to have better success in zones 7-9, and with transplanting in the right conditions, grow year-round in containers or in the ground.

When to Plant

Cooler soil encourages strong root development before frost.

Before we get into where to plant garden mums, when to plant them plays a key role in their success. The best time to plant mums is in the fall or spring, when roots can establish before freezing or hot temperatures. For fall planting, six to eight weeks before heavy frosts allows roots to develop in advance of winter. Protect roots with an insulating layer of mulch.

With the potted nursery mums we buy in the fall, planting them late in the season brings a risk of exposure to winter conditions. From the greenhouse, most of their energy goes into flowering for the seasonal display rather than establishing roots. It’s best to try to overwinter these indoors for planting out in spring.

Where to Plant Mums

The best site with proper cultural conditions makes for nearly effortless, long-lived, hardy mums. Good air circulation with proper spacing is essential for preventing fungal diseases. Plant them at least 18 to 24 inches apart, depending on the variety, for plenty of airflow around stems and leaves.

By Design

Leaves quietly frame summer flowers until autumn arrives.

Chrysanthemums light up the perennial border in the fall. All spring and summer, they quietly provide an attractive leafy backdrop to other performers. They set their buds in July, which develop until shorter daylengths trigger flowering late in the season. 

To capture the seasonal beauty, situate mums in the middle to the front of the border. They’ll softly mound until the glorious show. They work well to cushion edges and spill slightly over the tops of walls. Pair them with other autumn perennials like aster, rudbeckia, helenium, sedum, and ornamental grasses for a showstopping display.

Chrysanthemums also show some effectiveness at repelling common pests with their aromatic foliage and essential oils. The oils deter mosquitoes, fleas, and ticks—a fine reason for adding more around porches, patios, and outdoor areas that people and pets enjoy. A greater number increases the chances of deterring pests.

Mums have benefits that span the ornamental, herb, and vegetable beds as companion plants. Their showy blooms attract beneficial insects like ladybugs, hoverflies, and lacewings, which prey on pests like aphids and spider mites. Their aromatic toxins may make the surrounding area less attractive to feeding pests. 

In addition to in-ground plantings, garden mums perform beautifully in containers. Employ them as single specimens or to accent grasses and seasonal blooms like marigolds, violas, and snapdragons. Mix up the composition with leafy greens like Swiss chard, lettuce, ornamental cabbage, sage, and parsley.

Best Location

Slightly acidic ground brings out the best blooms.

When deciding where to plant garden mums, observe the sunlight in the space. They grow best in full sun, with six or more hours of sunlight daily. While they tolerate some shade, they’ll show fewer flowers and leggier stems without enough sun. Plenty of morning sun exposure is ideal, with an east or south-facing location.

Chrysanthemums prefer rich, loamy soils with good drainage. Neutral to slightly acidic soils are optimal, with an ideal pH between 6.5 and 7.0 (the sweet spot for many plants). A soil test helps determine pH levels and nutrient levels at a given site. Doing a test in summer and any amending in fall gives soils ample time for absorption by the spring growing season.

Prepare your transplant area by checking soil quality and adding compost or broken-down organic matter to increase richness and aeration. Lightly turn the soil to loosen it and promote root development for seedlings.

Making Sure Mums Come Back

Early watering gives young plants the best start.

Mums are low-maintenance, but new transplants need consistent moisture as roots establish in the first growing season. Water the transplants thoroughly at planting. 

Topdress with a layer of mulch, keeping it off the crown and stems. Mulch helps to regulate soil temperatures, retain moisture, and suppresses weeds.  

A few weeks after spring planting, apply a balanced granular fertilizer. Hold off on fertilizing fall-planted mums until spring, as they’ll prepare for winter dormancy rather than producing new growth.

End of Season Care

Cut back stems carefully to avoid damaging crowns.

After flowering and with heavy frost, the herbaceous perennials enter winter dormancy. In cold climates, leave the dormant stems in place for insulation. Cut them back in early spring within a few inches of the soil level to make way for emerging new growth. 

Overwintering

Container plants benefit from a cool, sheltered dormancy.

In lower growing zones, extra mulch insulates for added cool-season protection. This time, apply a light layer of mulch or soil on the crowns. A layer of evergreen boughs protects against ice and frost heaving as soils freeze and thaw.

To overwinter potted nursery mums, transplant them to a larger container. In cold climates, move those in containers to a cool, sheltered location, like a garage or basement, for dormancy. Water only as needed, checking the soil moisture occasionally to keep roots from drying out completely. Move them back outside or to a garden bed as the final frost passes and temperatures warm in spring.

Dividing

Crowded crowns benefit from splitting for healthier growth.

Over time, mature chrysanthemums become less vigorous. Dividing mums rejuvenates growth and promotes flowering by reducing overcrowding and competition for resources. It also creates new plants to expand the collection for years of recurrent color.