If you’re desperate for a late, late show, you can’t beat the chrysanthemum in November
The Chinese have a saying – “if you would be happy for a lifetime, grow chrysanthemums”. They’ll certainly make you happy in November by bringing cheer and colour to otherwise flowerless plots. It’s perhaps for this reason that garden ‘mums’ are making a big comeback. Increasingly, gardeners want more value from their smaller plots all year round and are attracted to plants that will deliver colour and extend seasonal interest in the garden.
Wildlife such as hoverflies, bees and butterflies will also appreciate that extra bit of nectar. So if you like rich autumn colours such as ruby red, deep pink, russet, yellow, gold and orange, then mum’s the word!
Hardy chrysanthemums flower from around September through to November or even as late as December in some areas, and are not to be confused with florist chrysanths which are far showier but need to be lifted over winter.
Check when purchasing that they are in fact hardy – garden centres also sell bedding types that won’t last through the winter so you may need to purchase from a specialist nursery instead. In very cold areas it would be a good idea to cover the crowns with a dry mulch to protect over winter.
Hardy mums will do best in open sunny positions – they’ll blend well in a mixed border and are also great for pots and containers. Plant alongside other later flowering perennials such as rudbeckias and asters for a really jolly display.
When planting, prepare soil as you would for most herbaceous perennials with a generous dollop of wellrotted garden manure or compost.
During the season be careful not to overfeed as you can get floppy growth. Pinching out when they are developing buds can help promote bushier growth, or do the Chelsea chop to cut them back in late May/early June to maintain a compact shape.
Cut down after flowering and mulch around the crown. Like most late flowering perennials, if you need to lift and divide, do so in spring. Doing this every couple of years will stop them becoming woody and leggy. You can also propagate from cuttings in May.
The main problem you will encounter is chrysanthemum white rust. This is a fungus that does well in cold, wet conditions and is identifiable by yellow and brown spots on the leaf with corresponding pustules on the underside which can turn white.
It can lead to shrivelled leaves or general stunted growth. As with most fungi, you need to be vigilant and remove and destroy any affected leaves or the complete plant if severely affected. Fungicides need to be applied regularly to be effective.