How Tall Do Chrysanthemums Grow? Classifications & Growing Tips

Most mums are bushy and typically grow to heights of 1 1/2 to 3 feet and 3 feet wide, depending on the cultivar, but they can also grow to heights of 4 feet or more. Although it depends on the variety, mums typically grow in USDA plant hardiness zones 3 to 9. So if you’re looking for a flower that will add curb appeal and beauty to your garden, chrysanthemums are a perfect choice!

Classification of Chrysanthemums

Anemone

In contrast to Semi-Double chrysanthemums, the flowers in this class have a raised center that resembles a pincushion. This class of chrysanthemums can be seen in our Kengai, or cascade, display.

Brush and Thistle

These chrysanthemums resemble either a thistle or a paintbrush used by an artist. While the thistle form has florets that twist around the stem or spread out horizontally, the brush form has delicate, tubular florets that grow upright.

Decorative

This category of mothers is very prevalent. This shape is typical of garden mums. Compared to the first three classes, the shape of the flowers is flattened. The florets are typically small. Lower florets typically reflex, while upper florets tend to curl up (bending down). This type of chrysanthemum can be found in our Kiku Kengai, or cascade, display.

Intermediate Incurve

This well-known class has shorter, partially incurving florets and a more open appearance than the Irregular Incurve. It appears to be a cross between irregular and regular curves.

Irregular Incurve 

These are the world’s most enormous chrysanthemum blooms. Many of the chrysanthemums featured in Kiku’s ogiku, or single stem, display are from this class. This class also produces some ozukuri or thousand blooms. The florets are loosely incurved, curing upward and folding into the plant’s center. The flower’s lower florets fall in an irregular pattern, giving the bloom a skirted appearance. Many of the flowers in this category have a 6 to 8 inches diameter.

Pompon

These chrysanthemums have a tiny, globe-shaped bloom that, when young, is flatter and eventually rounds out as it ages. The florets either have an incurved shape or reflex normally. The size of the flower can vary from one to four inches.

Reflex

The florets in this category curve downward. When fully opened, the bloom’s tops have a somewhat flattened appearance. The flowers have been described as having a mop-like appearance by some. Others claim that the florets overlap, giving the flower the appearance of bird plumage. These flowers are smaller than an irregular curve, but their diameter can still reach 4 to 6 inches.

Regular Incurve

This is the category for those who enjoy balance and structure. The florets form a lovely round bloom resembling a ball. The flower size can reach up to 4 to 6 inches in diameter, hence the former name of this category, “Chinese.”

Single and Semi-Double

This is a typical daisy-shaped bloom found on a variety of Asteraceae plants. Several rows of ray florets, typically between one and seven, surround a central section of disk florets. Our Kiku Kengai, or cascade, display features this class of chrysanthemums.

Spider

Long, tubular ray florets in this class have hooks or coils at the tip. There are both fine and coarse florets. The florets appear to have barbs on their ends and fall in a loose mass. Mums made of intricate spiders resemble fireworks displays.

Spoon

This class of ray florets has long, tubular ray florets that are spatulate or spoon-shaped. This flower’s central disk is visible and rounded. Except for the ray florets (outer petals) that resemble spoons, it resembles Semi-Double very closely.

Quill

This class of blooms has fully double flowers without an open center. The florets have open tips that resemble quills and are straight and tubular.

Unusual

These flowers fall outside of all other categories. The twisted florets can make them look very exotic. These are frequently the Edo varieties you see in the display of shino-tsukuri, or driving rain. This class produces some of the ozukuri or thousand blooms. The florets can have a flat, spoon-like, or quill-like shape. Members of this class frequently exhibit traits from different classes.

Growing Tips for Chrysanthemums

Water

Even moisture is necessary for mums to grow at their optimum. Watering must be done regularly during the spring, summer, and fall. Watering can be stopped once the ground freezes over in the winter until the soil warms up in the spring. Watering in the early morning at a depth of 6 to 8 inches is advised. Mums respond well to watering techniques that apply moisture straight to the plant’s base. This keeps moisture from getting sucked up into the dense foliage. A water timer can help you avoid remembering to water manually, while soaker hoses can deliver uniform, consistent moisture to the ground.

Fertilizer

All plants need nutrients. When fertilizing, your mums receive an additional boost of vital nutrients for the best growth. Chrysanthemum plant varieties grow most actively in the spring and early summer. Chrysanthemums, in growth, require a lot of food. Regularly applying high-quality fertilizers will encourage your mums to bloom and grow bigger. From early spring until July, pick a well-balanced, water-soluble fertilizer for monthly application. If you plant mums in the fall, wait until spring to fertilize them. Fall fertilization can make chrysanthemums less resilient to harsh winters.

Prune

Don’t stress about chrysanthemum pruning. Mums are pinched throughout the growing season rather than being “pruned.” This encourages the plant to grow branches, fill out, and produce more blooms. Pinch off 1 inch of each shoot when your plant is 6 inches tall in the spring. Repeat this until early summer, every two to three weeks. For a more extended bloom period throughout the fall, deadhead spent blooms. Refrain from cutting the plant back once it has died during the winter. According to research, letting it naturally die back over the winter produces a more vigorous plant. In the spring, remove the dead stems and foliage.

Sunlight

Chrysanthemum plants are hardy and can handle light exposures ranging from full sun to partial shade. They will typically do well in climates where sunlight reaches the ground at least 6 hours per day. Additionally, they prefer soils that are well-drained but rich in organic matter.