What to Know About Planting and Caring for Chrysanthemums
By Laura Bullard
Chrysanthemums (or mums) are small, low-lying shrubs that produce bright, show-stopping blooms in the late spring and early fall. While they are the official flower of Chicago, chrysanthemums are grown across the United States and thrive in hardiness zones 5–9.
Incredibly easy to grow, chrysanthemums are one of the most popular low-maintenance perennial plants. If properly planted and lightly attended to, your mums can bloom for years to come.
Because they differ so widely in shape and size, the National Chrysanthemum Society has categorized them into 13 distinct (but occasionally overlapping) classifications.
Types of chrysanthemums
Irregular incurve mums
Irregular incurve mums are best known for their massive, six- to eight-inch blooms. Their florets curve inward, completely covering the center of the flower. How tight or loose the florets hug the center depends on the variety, but the blooms are (more or less) spherical.
Irregular incurve mum
Reflex mums are also spherical. Often compared to bird plumage, the florets are downward-curving. Like incurved mums, the florets completely cover the center of the flower. The blooms are usually around four to six inches in diameter.
Regular incurve mums
Regular incurve mums are quite similar to irregular incurve mums, but the way their florets curve inward is much more uniform and tight. The four- to six-inch blooms are completely spherical.
Regular incurve mum
Decorative mums have both incurving and reflexing florets. The upper petals tend to curve upward and inward around the center and the lower petals tend to reflex downward. The blooms are typically at least five inches long.
Intermediate incurve mums
Intermediate incurve mums are the most popular classification. Their florets incurve upward, but they don’t fully cover the center. Usually, the blooms are at least six inches in diameter.
Intermediate incurve mum
Pompon mums are spherical, but they don’t have the long florets found in chrysanthemum classes 1–5. The short, cupped, tubular petals incurve upward or reflex downward, completely concealing the center of the bloom. The blooms tend to be only around one to four inches.
Single and semi-double mums
Single and semi-double mums resemble daisies in that they have extraordinarily pronounced centers surrounded by one or two rows of florets. The petals don’t dramatically reflex or incurve—they shoot straight out of the center of the bloom in stunning rays. The blooms are always at least four inches.
Anemone mums are often called cushion-shaped mums. Typically at least four inches, they are very similarto single and semi-double mums, but the center (or the “cushion”) is significantly more pronounced.
Spoon mums are nearly identical to semi-double mums, but the tip of each ray floret looks like a tiny spoon. The blooms are always at least four inches.
Quill mums have long, tubular florets. The six- to eight-inch blooms incurve slightly, completely covering the center of the bloom.
Spider mums are similar to quill mums (the florets are long and tubular), but each floret tends to end in a hook or a coil rather than a simple point. The florets also tend to be thinner, which makes the bloom look “coarse.” They tend to be at least six inches.
Brush or thistle mums
Brush or thistle mums actually look like paintbrushes—their long tubular florets growing perpendicular to their centers. Brush mum blooms are quite small. They typically don’t get larger than two inches.
Exotic mums (also known as unclassified mums) are, quite simply, mums that don’t fit into any of the above categories. Typically, they have the characteristics of at least two other categories. For example, they may have incurving, tubular florets that are also spooned.
When to plant chrysanthemums
Chrysanthemums need at least six weeks to get established before they encounter extreme heat or cold. Because of this, most gardeners plant their mums in the spring. If given enough time to properly take root, they should bloom by late summer or early fall.
If you plant them too early or late in the season (in the heat of summer or just before winter), they may bloom, but only once. If planted in the spring, chrysanthemums will bloom year after year.
How to plant chrysanthemums
You can either purchase your mums from a garden center or propagate them yourself with cuttings. If you’re starting your mums from cuttings, follow these simple steps:
Remove a four- to six-inch stem from a thriving chrysanthemum. Make sure there are at least four leaves (or leaf nodes) on the stem. Make your cut in the morning, when the plant is most hydrated.
Remove all of the leaves on the bottom half of the stem and place your cutting in perlite soil. Make sure at least two leafless nodes are below the soil.
Keep the soil moist and place your cutting in indirect sunlight. After three to four weeks, the roots should be at least one inch long. You can then transfer your cutting to a small container with regular potting soil.
After another five to six weeks, your cutting will be ready to plant outside.
Once you’ve purchased your chrysanthemums from a garden center or propagated them yourself, look for a spot in your yard that gets full, early sun.
Mums like at least five to six hours of sunlight every day. Because they’re susceptible to mildew, make sure the soil is well-draining and not too low-lying or damp.
First, dig a hole that’s at least two times larger than the size of your root ball.
Space your mums 18 to 24 inches apart and cover the roots with soil and organic matter (compost, peat, etc.). The organic matter will ensure that the roots drain properly.
Pack the soil loosely and install support posts if necessary until the roots get established.
Caring for your chrysanthemums
Early in the season, water your chrysanthemums as often as you water your lawn—about once a week. As your mums grow and begin to bloom, they’ll need more water. By the time they’re fully in bloom, you should be watering them around three times a week.
During the early summer, you should pinch off the tips of your young plants to encourage bushiness and heavy blooming in the fall. Remember, this is only helpful when your chrysanthemums are getting established. You don’t need to pinch mature mums (this can actually damage them).
Most mums can survive the winter, but not all of them can. Some gardeners heavily prune their mums after the fall bloom and, if you live in a particularly cold climate, you can mulch them before the first frost. Simply cover your mums in pine needles, hay, or evergreen leaves until the spring.
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