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  • Writer's pictureAnna

Over Wintering Dahlias

To lift or not to lift, that is the question?

It's that time of year again in the UK where, here in the South East, we are still waiting for our first frost as a sign that the dahlias need to be put to bed for the winter. Other parts of the UK may well have already had many frosts but so far here it's been very mild and wet. For those of you who are new to the wonderful wonderful of dahlia growing and aren't sure what you should be doing or when then hopefully this will help clarify a few things for you.

I've been growing dahlias for a few years now and every year have expanded the number of dahlias I grow. What started out as a few plants in pots on my terrace, is now two 13ft x 4 ft raised beds full plus many many pots full as well as selling off excess tubers to customers and friends. I've now got to the point where the choice of whether to lift them or not has been taken away due to lack of storage space, time, bad back issues etc. However, if you are a novice gardener or new to dahlia growing (with a few dahlia plants) you do have a choice, especially if you live in the relatively mild climate in the South of the country. So, for those of you that aren't sure what you're supposed to be doing right now here are my tips on the two different options you have.


So after a hopefully successfully flowering season your dahlia plants will need the winter to recover. Don't be tempted to lift them too soon. You want to wait for the first frost to blacken the foliage. Once this has happened cut all the stems down to 2-4" above the soil level and very carefully dig up your tubers. Be really carefully not to spike or damage the tuber. I usually clean the excess soil off my dahlias at the time of lifting using my hands to brush off the worst of it then a hose to wash off the rest. Then leave to dry in a frost free place for a few days so they are completely dry. Do not pack them away wet as they will rot. Leave about 1-2" of stem on and remove any damaged or rotten parts of the tuber. This is also a great time to divide them. You need to make sure you have at least one eye on each part you split for it to grow. Make sure you label very well at this point so you know what you've got come Spring. This is always my downfall every year. I'm still looking for a reliable labelling method that is eco friendly and doesn't rot. If you have more than one of the same variety you can always use one box just for them and label the outside of the box. If its a mixed box then you need to attach the label to each individual tuber. Believe me, you'll be very thankful you did this properly as when it comes to planting you won't know what you're planting where come Spring! Store the tubers in a ventilated box in compost or sand and put in a cool dry place. The temperature should be about 45-55 degrees ideally. I store mine in my garage. Check your tubers periodically throughout the winter to make sure there aren't rotting or overly dry. If you see any rot cut it off so it doesn't spread and if they appear very dry and shrivelled then give them a light misting of water. Leave them in storage until early Spring when it's time to start waking them up again. I'll post another blog nearer the time to let you know what to do at that time.


So this is the option I'm going to trial this year after the back breaking and very time consuming dahlia lifting and dividing I did last year. If you have a lot of dahlias and nowhere to store them and live in the relatively mild climate of the South then you should in theory be fine to use this method. Although my research has shown up that some varieties do not like being left in the ground. I think trial and error is needed and be prepared to lose a few while you discover which varieties can handle the winter weather where you are. I suppose it depends on how cold or wet our winter is which no one can predict. To be honest the time saving alone from not lifting them will definitely more than make up for maybe having to replace 2-3 tubers each year. I would however recommend lifting and storing dahlias that have been grown in pots or tubs as these tend to get frost bitten and rot easily. So use the lift and store method for these.

Firstly, remove the stems after the first frost leaving just a couple of inches above the soil. Pile on as much compost or mulch as you can. And I mean a lot! I've been told about a foot should really protect them. You will notice that the stems are hollow and you need to make sure that they are really well covered to stop frost and rain water getting in them and killing the tuber. Once covered put a stake in and label so you don't forget what dahlia it is.

In February you need to be ahead of yourself with the slug protection. DO NOT wait until the first signs of shoots. In early February use an even sprinkling of ferric phosphate slug pellets all over the area not just around the plant. These are organic, pet and wildlife friendly.

Whichever method you use you need to accept that you may lose the odd tuber every year but the majority should give you wonderful plants for quite a few years if looked after properly. When I divided my tubers last year I ended up with more than 3 times the amount of tubers I started with. One thing's for sure, once you start growing dahlias and realise how easy it is and how productive they are you won't want to have a garden without them. The sheer variety of colour, shape and texture is incredible. There is definitely something there for everyone.

I'll post again in early Spring with details on how to wake up your dahlias and get them going for a healthy and bountiful season next year. Until then stay warm and remember there is a reason nature hibernates in winter. Maybe we should take note and be kind to ourselves this winter. Slow down, rest, eat healthily, take long walks in the fresh air, read the books we've put off while it was nice outside and get lots of restful sleep.

Anna x


Tulips...what, when & how.

Come back soon for my tulip tips as it's tulip planting season once those dahlias are all sorted for winter. Find out my favourites and tips on how to keep the pests away!


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