Perennials: Chrysanthemums

 

	20cm-1.5m (8in-5ft)
	30cm-60cm (1-2ft)
	Late summer to fall (frost)
	Well-drained soil
	Sunny position
	Powdery mildew, Rust, slugs & snails, leafspot, leaf miner
	Cut back after bloom
	Medium
	Low

Chrysanthemums

Common Name: chrysanthemum
Family: Asteraceae
Native Range: None
Bloom Color: White, yellows, reds, pinks, purple, mauve & bronze

Incredibly diverse, Chrysanthemums are available in a truly massive range of colors with various types of bloom ranging from the basic daisy-like flower of Chrysanthemum maximum, known as the Shasta Daisy (shown at the top of this page) to the complex spoon-petalled chrysanthemum 'Pennine Ace' which is shown to the right (click photographs to view enlargements). Chrysanthemums owe their popularity to the vast range of colors and shapes availble with the single flowers being extremely popular. There are many other types of bloom types including double, pompon, semi-pompon, incurved, reflexed, intermediate, anemone and the those with unusual, spidery like, flowers with petals described as spoons or quills.

The most widely varied species of chrysanthemum are the group known as florists' Chrysanthemums. Surprisingly these garden plants are very hardy and can still be found blooming at the start of winter. Even in cold gardens the chrysanthemum can remain in flower until the first hard frost making them extremely useful at a time when many other perennials have died back. By using chrysanthemums and other late flowering garden perennials such as the Aster, it is possible to have a wonderful looking garden when all others in your local area appear dull, colorless and lifeless.

Cultivation

Florists' chrysanthemums should be planted in shallow holes made in humus-rich, moist but well-drained soil towards the end of spring. The taller varieties will need external support so you should add a stake and tie the plants as they grow. To maintain a bushy habit, and to promote lateral flowering, you should pinch out the growing tips when the plant reaches a height of around 15-20cm (6-8in). Please note that this should not be done with spray types of chrysanthemum.

To ensure that your blooms are large, strong and healthy it is best to only allow your chrysanthemums to develop a maximum of six flowering stems. Keep an eye on your plant and, from mid-summer, you should remove any side-shoots and buds from around the crown (the center bud on a stem). After flowering, and before the first frost, you should remove all the stems, lift and keep them in a cold frame or greenhouse over winter.

Border chrysanthemums are treated slightly differently and should be planted from early fall to mid spring and, after flowering, they should be cut back to the ground level.

Propagation

Florists' chrysanthemums can be propagated by starting the growth in late winter and taking basal cuttings in late spring. The cuttings should be about 5-6cm (2-2.5in) and planted in a propagator (or glass covered box). Once rooted they should be transferred to individual pots of potting compost, 7.5cm (3in) pots are best, and they should be kept cool. Pot on the plants as the roots fill the pot and plant out the following spring after the last frost.

Border chrysanthemums are also propagated by basal cuttings but they are taken slightly larger at 5-7.5cm (2-3in) and taken in mid spring. Cuttings can be planted in a cold frame and planted out when rooted. Border chrysanthemums can also be lifted and divided in spring.

Pest and Diseases

Chrysanthemums can suffer from a number of pests and diseases. The chrysanthemum leaf miner weakens and disfigures plants by tunneling into leaf tissue. Slugs and snails also love to feed on leaves, stems and flowers.

Powdery mildew can make a plant unsightly covering the leaves, stems and buds in a white dust. Rust in aggressive and spreads fast, appearing on the underside of leaves as pinhead sized reddish brown pustules which are powdery. Easier to spot (excuse the pun) in leaf spot which appears as, up to, 2.5cm (1in), circular, brown to black spots.

In later articles we will take a look at some of the popular species of chrysanthemum.

 

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