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Woodgreen wonderboy

Hello everyone, I grow lots of dahlias every year... they never went out of fashion in this garden!   However I noticed today an interesting result of my efforts. In an effort to be reasonably scientific with the trial I never intended the results are as follows:-

1. Tubers lifted last autumn and stored in dry stable, potted up a few weeks ago. These have almost all thrived with very few losses 

2. Tubers not lifted and left in the ground, mulched with old potting compost. These have all survived the coldest winter for years.

3. Tubers in large tubs, left in tubs and overwintered in GH, still in same compost with liquid feed added, all doing well.

4. New tubers, bought from GC in spring (carefully choosing largest/plumpest available), potted up ...significant failures/no-shows 

The moral of this tale is that you should trust your own efforts and that the growers/GCs need to raise their game. For about 1/3 not to grow is unacceptable.

I would be interested to hear your dahlia stories this year.


The ones I left in the garden, no sign.  3 that I wrapped up in layers of newspaper and put in a cardboard box in the Gh, dead. I think they knew i didn't really like them

Woodgreen wonderboy

 Nut,You may be colder in the far east, as I am in the deep south. The dahlias I store are just put in cardboard boxes, which are piled up in my stable (no horses) and covered in fleece/hessian. This allows the air to circulate which is important probably.

This autumn I think I will leave all my dahlias in the ground. Not only does it seem to work here but I could do with a bit less work as the years go by.


We have to look to how we're going to cope later. One of my strategies is to plant theslopy bits of garden with evergreen plants so I don't have to walk on them in my old age. It may be too late.

My MIL's technique was to wrap them up and put them down the middle of the garage so they were between the wheels of the car. At some point most winters there'd be a casualty


Interesting. I left one Dahlia in the ground and it started to grow until I speared it in twane with my fork. It was very wet here in December, so am suprised to have seen it, as well as the Canna. Some Canna and Dahlia rotted for me in pots, even being in the garage from Nov-March. All lifted plants are fine. So my thoughts are leave them or dry them off properly and store.


Woodgreen wonderboy

I always lose a few, which is to be expected. This year I have been surprised at how many of the newly bought ones have failed to start.


The ones I lleft in pots survived, though one was very late starting and I did think Ihad lost it. Some were in the cold greenhouse over winter, some not - the larger pots I just could not move.  Don't have so many but all OK so far. 

I've found growing dahlias far easier to grow from seed rather than tubers.

The seed grown one's have produced cracking tubers after flowering, which stored well over winter but most have never grown again in spring. This year I bought two new tubers...and...only one sprouted.

The tubers which sprouted are in pots and romping away, seeded ones still fairly small, but outside in pots and I'm confident they'll produce some cracking flowers.

Excellent trial Ww. Pots in GH, seems like a good plan for my seed grown dahlias, or putting in a sheltered spot at the end of this year.


i am growing dahlias for the first time this year i bought the tubers from peter nyssen who i buy my bulbs from, all but two have grown but im not sure if it is beter for the plant to take some of the shoots off or nip them out, as you are the expert WW advice please

Woodgreen wonderboy

It is a good idea to pinch out the main shoots as this causes the plant to bush out with more flowering shoots and it will be stronger and less leggy. It will delay flowering for a bit but as they flower until the first frosts this is not really a problem. You MUST deadhead them to keep the flowering going full pelt, and it is a good idea to take the flower stalk down as far as possible ( but above any new buds) as otherwise you will eventually have a sea of stalks which detracts from their beauty. they are good for cutting for the house or giving to friends and this is good for them also. Enjoy, and you will buy more next year. 



thanks very much i will send pictures when they flower and no doubt ask for more advice


WW is your soil quite good and free draining? I don't grow dahlias but from your results it suggests that would make a big difference. If the ground was heavier and a bit wet in winter it would always be better to lift do you think? 

interesting woody

here its mild and several dahlias remain in the ground.  however i dig up many..pot up or even leave the clumps in the greenhouse.  i find those dahlias in pots are ahead of those in the ground at this time of the year but soon catch up and outgrow those dug up.

i find these trials very informative and i agree with woody about using common sense and trusting your own efforts.  the experts dont always know best i find.


Main problems with dahlias would be, allowed to get to cold, allowed to be too damp, allowed to be too dry. If you lift them and put them in a frost free dark place typically in a tray of dry compost, they may well get too dry. You should once a month try to remember to check and if the soil is getting too dry give them a misting with a hand sprayer on the surface of the compost. All mine came back this year amazingly (probably a fluke!) at my first time. This  year I'm going to try putting them in old tights or onion sacks, hanging them up, and just give them a mist now and again and see how that works out.

Side note, it is important to check them reasonably frequently, if one starts to rot, it can spread quickly.

I lift and store some but leave others in the ground. The ones I store, I dry out well and wrap in newspaper. I check them regularly during the winter months.

This year I started off my stored ones and some new tubers I bought, early spring under cover. All are outside now mostly in pots and some have buds despite being pinched out. The ones I left in the ground in the allotment has just started to peek up so they've survived the winter. I don't mind them being later as they'll be nice and bright when autumn comes and I'm digging up my harvest.


Woodgreen wonderboy

FG, My soil is free draining which I agree helps a lot. I intend to leave them all in the ground this year, and I will add lots of alliums in autumn for show in May/June next.

I also never, ever, check the ones I store. Lazy on my part but works for me . Again it probably helps that they are pretty dry before they go into store. I may lose one or two this way but checking would probably make no difference in my circumstances.

Am about to plant out my dahlias on Thursday or Friday, in advance of the open day on Sunday.

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