Garden Studios

EVEN if you’ve got away with leaving dahlias permanently within the ground in previous years, they’ve only survived due to a run of mild, dry winters. But in our current colder, wetter winters, they stand no chance. So a good way to keep them to grow again as opposed to forking out on new ones next spring, harvest the tubers and store them inside. Here’s how…

Get the timing right

Don’t rush to dig up dahlias simply because autumn has arrived. Frequently the plants look green and healthy and continue flowering, leave them alone. Wait until the 1st proper frost blackens the foliage and makes the plants look limp and sad.

Preparing tubers for storage

Cut the tops of the plants off about four to 6 inches above ground level. Then use a garden fork, pushed in about nine inches far from the bottom of every plant, to lever it out of the bottom. Take care to not prong the tubers, as they’ll rot if damaged. Leave the cluster of tubers intact and pick it up by the bottom of the stems.

Gently shake off the loose soil, carefully rinsing away any remaining with a slow-running hosepipe. Label each cluster by variety, then stand the wrong way up in a dry, sunny situation outside, with lots of space between them (besides allowing air to dry the tubers, this encourages any remaining sap to expire of the hollow stems, which helps the tubers to store well without rotting). Turn the tubers over carefully several times in order that air can reach all of the nooks and crannies. When they’re thoroughly dry, they’re able to put away.

Storing tubers

Dahlia tubers are killed by frost and damp, so it’s necessary to keep them in a dry shed or garage. But since they’re dormant, it’s okay to store them at midnight. Place the clusters of tubers in net hammocks slung from the roof, or in slatted stacking trays, spacing them out slightly to permit air to circulate.

Take precautions against mice, for you to nibble stored tubers. In case you don’t have an appropriate outbuilding, you’ll store your tubers in a spare room indoors, however it must be very cool otherwise they’ll dry out an excessive amount of. You should also leave them open to the air, instead of packing them in plastic bags or closed cardboard boxes.

Checking for damage

During the winter, check tubers for signs of damp, rot or rodent damage. If damage is located, cut away affected areas, which typically look soft and brown, until only greenish-white tissue remains. It’s often easier to take away a complete affected tuber from a cluster, cutting it off on the narrow junction where it joins the bottom of the major stem. To forestall further trouble, dust the open wound with sulphur powder.

Starting back into growth

Dahlia tubers will naturally begin to sprout in spring; plant them in late April with the highest several inches below the outside of the soil so the brand new shoots don’t emerge until after the last frost. Carefully harvested and stored, the identical dahlia tubers could be regrown for decades.

If you ought to propagate some extra plants, start potted tubers on a warm windowsill indoors in January and use the various strong, young, early shoots as cuttings after they are two inches long.