Mum Basics

Chrysanthemums (mums) are one of the most popular fall flowers for the garden. Most varieties are easy to grow with their basic needs being full sun, rich soil, good drainage, and good air circulation. There are hundreds of varieties available that can provide blooms from late summer through fall.
MUM BASICS
Zones: 5-9 (some varieties to zone 4).
Height/Spread: Varieties 1-3 feet/1-2 feet
Flower Color: Chrysanthemum flowers bloom in shades of white, yellow, orange, lavender, purple, or red.
Exposure: Mums prefer full sunlight during the growing season, and not enough sunlight will result in a weaker plant that will produce fewer flower heads. However, blooms will last longer if they are moved to a shadier spot after flower buds develop.
Soil: Mums prefer rich, well-drained soil. A good rule of thumb is if the soil is good for vegetables, it’s good for mums.
Bloom Time: September to frost. Mums are known as short-day plants, meaning flowering is triggered by the shorter days in late summer and early fall. Flowering can also be forced in a light-controlled greenhouse.
PLANTING & CARE
When to plant: For use as a perennial, plant mums in early spring or at least 6 weeks before a killing frost in fall. Spring-planted mums will have the best chance of surviving the following winter. If you are using them as an annual pop of fall color, plant them when blooming in late summer or early fall.
Water: Chrysanthemums require more frequent watering due to their shallow roots, especially in high heat or little rainfall. A layer of mulch in summer will help conserve water and keep the soil moist and cool.
Pruning: Pinch approximately 1 inch from the branch tips two to three times during the growing season to encourage branching and a sturdier plant. Early bloomers that bloom in mid-September, should be pinched no later than mid-June. October bloomers can be pinched up until mid-July, with the rule of thumb being not to pinch any closer than 3 months to bloom time.
Propagation: When mums are grown as perennials, they can be divided every two to three years in the spring. Dig up the plant when new growth begins to appear, discard the dying center and re-plant the new shoots on the outside of the plant. Mums can also be grown from cuttings taken in the spring. Cut just below a leaf node and root in sterile potting soil. The new plants should be watered daily and kept in a sunny windowsill until established.
Fertilizer: Mums are not big feeders, so it is best to apply a dilute fertilizer several times before bud set. A 5-10-5 fertilizer formulation will have the greatest effect on flower production and overall growth.
Diseases and Pests: Some diseases that can affect mums are leaf spot, powdery mildew, and viral diseases such as mosaic or stunt. Avoid overcrowding and overly shady locations that cause moisture to remain on the leaves and provide a habitat for diseases. Pests can include aphids, caterpillars, leafhoppers, leafminers, plant bugs, and spider mites.
DESIGN IDEAS
Chrysanthemums are great for growing directly in the garden or in containers, here are some ideas:
•Perfect for containers and baskets because of their shallow-rooting habit.
•Use as an annual in the fall to fill in and replace summer-blooming annuals.
•With the many color varieties available, mums can provide coordinating or contrasting color accents to both indoor and outdoor spaces.
•Mums are relatively inexpensive, making them a great choice for large groupings or repeated throughout an area.
GARDEN MUM VS. FLORIST MUM:
The difference between garden and florist mums comes down to their hardiness. Garden mums are typically the varieties you would plant outdoors in your garden and are hardy in their specific zones. Florist mums are used solely for indoor potted plants and are not suited for transplanting outside. Make sure you are buying the correct type for your intended use and location.
FREQUENTLY ASKED QUESTIONS
Are chrysanthemums annuals or perennials?
Although the most widely available mums are grown as fall annuals, there are varieties that can also be grown as perennials in some regions with a little care to over-winter them. In colder zones, leave the top growth in place and add loose mulch such as straw or evergreen branches around them for protection, waiting to cut back in spring after new growth emerges. In warmer winter climates, they can be cut back to 6” tall after flowering. Check your local garden center to see what varieties work best in your area.
What about the potted mums sold at supermarkets and big box stores?
These affordable plants show up in stores during the fall and have a tidy mound of small flowers. Sometimes called garden mums or Belgian mums, these plants are typically grown as annuals. They are popular for use as part of an autumn container display. Most gardeners report that they aren’t as hardy as the mums featured above and rarely winter over.
Are mums poisonous to cats, dogs or other animals?
Mums do contain substances that are toxic to cats, dogs, and horses if ingested, so be sure to keep this in mind when choosing a location that might be explored by curious pets. See more Common Poisonous Plants for Dogs and Cats.
Are mums deer and rabbit resistant?
Deer and rabbits tend to avoid plants with fragrant leaves and fuzzy texture, both of which are attributes of mums, making them fairly resistant.