What am I doing wrong with my dahlias?

[gray1720]

I fished the tubers out of the attic about a month ago, when they were just starting to shoot. Put them on top of the bed in the greenhouse, regularly watering them to encourage them to get going before I plant them out. It's always worked before... This year all that  has happened is that the shoots have gone from white to green, no further growth at all.

Has the sun cooked them?

[gray1720]

[Beersmith]

Cooked them? Well it is certainly possible. I start seedlings in a conservatory and have killed a few by forgetting to open vents on hot days.  This year I baked my first set of celeriac seedlings.

But when it comes to dahlias I must admit to total ignorance.  So much so that I'd grown them for several years before I learned about lifting them over winter. Now that I am aware of their potential vulnerability to cold conditions I mulch them well in the autumn but still don't worry about lifting.  They take their chances and yes I did lose one after one very cold winter but usually they start to pop up about this time of year pretty reliably in their established bed.

[Tee Gee]

1)I fished the tubers out of the attic about a month ago, when they were just starting to shoot.

I assume you plant tubers and not cuttings!

2)Put them on top of the bed in the greenhouse,

I think you might have encountered a problem here because April was quite warm during the day but often cold at night

3)Regularly watering them to encourage them to get going before I plant them out.

You might have over done this as well!

4)It's always worked before...

The seasons are not what they used to be, so again another possibility.

5)This year all that  has happened is that the shoots have gone from white to green, no further growth at all.

They may have aborted due to this crazy mixed up weather.

Must admit I have never used this method as I always took new cuttings every year!

This was my way;

https://www.thegardenersalmanac.co.uk/Content/D/Dahlia/Dahlias.htm

[gray1720]

Well, I'm tempted to be cheeky and say I plant cuttings but no, it is indeed tubers! Thanks for the pointers. I spoke to my Mum as well last night - she thinks it might be the cold too. The other thing I've realised that is different is that I normally stand them in seed trays with a bit of compost round them, this year I put them straight on the surface of the bed. That means they are less insulated than they have been in the past, which would exacerbate any chilling.

Of course, it's now turned cool and wet...

[gray1720]

Now that they are starting to move a little bit...

The night time temperatures are forecast to fall into single digits again. Grr!

[Tee Gee]

The night time temperatures are forecast to fall into single digits again. Grr!

I always had a piece of fleece handy for such occasions!

[gray1720]

I've got some big sheets of bubble handy, but am also away for a night, so (classic gardener's dilemma) do I risk them chilling at night without or cooking in the day with? Argh!

[Tee Gee]

Prop up / support the plastic to ensure it is not touching the plants/ tubers this will allow movement of air around any leaf formation.

[terrier]

My dahlia tubers are in the cold greenhouse and don't seem to be any worse off. If you are worried about being away for a day or so, just bring them into a cool shady place (shed or indoors), that should do them no harm.

[gray1720]

Good points both - ta for the tips!