There’s no doubt that Dahlias really are the stars of the show in the Autumn garden and are well worth including in your planting scheme either within borders or as part of a seasonal cutting garden - the variety of colours, shapes and styles is sure to mean there is something for everyone.
Some gardeners are put off growing Dahlias because of worries about having to lift and store the tubers over winter and the risk of losing plants to frost or pests. Even experienced gardeners go through the usual ‘should I or shouldn't I dig them up for the winter’ anxieties but there are a few things you can do to give your Dahlias the best chance of sailing through the winter unscathed and coming back stronger next year.
How to overwinter Dahlias
Lift and store
If you choose to dig up the dahlia tubers before the first frost, we recommend you keep them in a cool, dry place until the spring. When storing tubers indoors, always ensure that they are kept in a cool, dry place such as a garage or basement, and make sure that they are kept in a cardboard box or paper bag away from direct sunlight. It is also important to check the tubers periodically to ensure that they are not drying out or becoming mouldy.
Leave them in the ground
Alternatively you can leave Dahlia tubers in the ground over winter, particularly if you live in a more temperate area. Cut the stems back and clear away any decayed foliage and then mulch with an insulating material such as fern or hedge clippings over a generous area - not just around the stem - to protect the tubers and root system underground. A Bell Cloche or fleece will offer extra protection.
In spring watch out for slug and snail damage and remove the remaining mulch material so that the sun can be heating the soil and those tubers below.
If you are planting Dahlias for the first time and would like to avoid having to lift overwinter these are some varieties that can generally be left safely in the ground for years:
Glorie van Heemstede
Waterlily-like flowerheads, up to 15cm across, look luminous against the backdrop of the rich green foliage when they appear from midsummer onwards.
Semi-double pink dahlia with a gentle transition into yellow towards the centre. A decorative Dahlia reaching unto 75cm in height.
Glorie van Noordwijk
An eye-catching Dinner Plate Dahlia with huge and magnificent, butterscotch blossoms, up to 20cm wide.
A classic border dahlia with beautiful, glossy, rich chocolate-coloured leaves, contrasting to orange and ochre flowers and ideal for the front of a border.
A ball of perfection, a pompom dahlia that is almost perfectly round and doesn't have a single rolled cup-like petal out of place.
Creme de Cassis
A distinctively coloured dahlia, 'Creme De Cassis' has a perfect arrangement of delicate petals that blend from burgundy to a pale pink.