When do chrysanthemums flower?

Chrysanthemums are the flowers that you add to your garden to produce colour when everything else is fading away. Affectionally known as mums, chrysanthemums varieties are either early, mid- or late season blooming. That is, they start to bloom in August and early September, or late September through October, or late October, November and even into December. We discuss each of these blooming periods for mums that you grow in your garden.

What are some types of early flowering mums?

Early flowering mums start to bloom in the autumn –  August and early September. However, you should plant them out in the garden in early May, after the last frost, to make sure that they have enough time to establish their roots and a strong plant structure. Position the plants about 60cm apart if you want them to spread out, or closer if you’re growing them just for cut flowers. Fertilise the mums every fortnight until the buds start to develop in August.

If you use the National Chrysanthemum classification system, look for plants whose alphanumeric code starts with 22-30, denoting a September bloom time.

Read next: What are the different types of chrysanthemums?

Here are some to consider:

Chrysanthemum Chessington (various)

This variety of mum grows to about 1.8m in height, making it the showpiece of your summer garden. The large blooms have strongly up-curled petals that form a tight ball. The Chessington line of mums comes in a colourful selection including Chessington Apricot (white under the petals that show with orange on the upper part); Chessington Lilac (pale pinky lilac); Chessington Primrose (a creamy yellow) and Chessington Yellow (a strong bright yellow).

Chrysanthemumanthemum NHS Rainbow

This mum grows to 1.4m in height, providing a tall plant in your garden. The large pink blooms have curled up petals forming a multi-layered bowl shape. If you pinch out the plant in March, (that is, stop the main stem growth and encourage the plant to grow from the leaves below the pinch), this mum blooms in September.

What about mums for blooming in October?

Varieties of mums labelled in the categories 13-20 in the national classification system are developed to bloom in October. Pompom mums are generally mid-season bloomers as are some reflexed varieties – these have long, thin petals that point downwards but are still in a ball shape with the centre visible on top.

Here are two varieties to check out:

Chrysanthemum Charles Tandy (various)

This variety of mum grows up to 1.6m tall and produces spherical blooms in white, light yellow or dark yellow depending on the type you choose.

Chrysanthemum Pauline White (various)

This is a shorter plant at 1.1m that produces whimsically shaped pompom blooms. The Primrose variety has pale yellow flowers while the Salmon variety has a hint of blush pink.

What are the latest flowering chrysanthemums?

These mums flower in late October through to December but do it inside your home. You generally grow late-season mums in pots so that you can bring them inside for the winter – either in your home or in a greenhouse. Make sure to rescue them from the garden before the first frost, though they can survive the first wisp of cold. You can grow them in your garden in the soil in the usual way until about June, but then pot them so they establish themselves firmly in their new environment before blooming time.

Late season flowering mums are designated as categories 1-12 in the classification guide.

Here are two varieties that I especially like:

Chrysanthemum Masons (various)

If you like warm colours in your garden in the late growing season, this mum is for you. It grows to a maximum height of 1.5m and its single daisy-like flower per stem definitely attracts the eye in an otherwise sparse landscape. Choose from Masons Bronze (a warm orange), Masons Golden (a lighter orange) and Masons Golden (a sunny yellow).

Read next: Are chrysanthemums perennials or annuals? – How to decide

Chrysanthemum Shamrock Green

This is a spray mum that can also be grown as a single flower, so the choice of its shape is yours. Whatever their shape, the stunning blooms on this plant are a green colour. The petals are long and thin and grow upwards and incurved together in an anemone shape.

Please keep in mind that the heights of the plants given here are the maximum heights attainable by plants put into the ground in the best possible soil early in the growing season.

For more detailed information about caring for these beautiful plants, head over to How to grow chrysanthemums – the beginner’s guide and continue with Growing chrysanthemums in pots and containers.

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