Geranium through winter?

JoeX

I’ve tried keeping them out through winter and not had any luck, but this year they seem to have large healthy root systems…is it worth trying again?

Previously I’ve cut them back and mulched over, as I have no greenhouse.

Im on the London/Kent border

bédé

What care can you give them?  "Keeping them out" is unlikely to work.  Where were they during the last few frosty nights?  London-Kent is not that balmy.

Keep them dark, dry and frost-free.  And look at them every 2 weeks.  Any signs of rot/shrivelling - cut it off.

fidgetbones

The only way pelargoniums  would survive  over winter is if you pot them up and bring them inside.

Fairygirl

I agree with @fidgetbones. That's the only guaranteed method. 
Many people in London, or on/near the south coast, seem to be able to keep them outside, but it must be very light frosts they get, and the soil must be much drier for that to work reliably. Cold wet soil is a real killer.
You can take cuttings while there's good, green growth, but that looks too far gone to be of  any use. 

JoeX

The snow took them down.

I can put them in an unheated shed or garage to keep them dry?

I believe these are geraniums, not pelargoniums but I have forgotten how to distinguish them?

Fairygirl

Geraniums are completely hardy. Snow doesn't affect them. Even wet then freezing doesn't affect them.
Pelargoniums aren't hardy.
If you have a photo of them in flower it's easy to ID them, but that pic doesn't look like a hardy geranium.

Topbird

Those fleshy stems definitely look like pelargoniums.

Pelargoniums will survive winter outside here if it's both a mild winter and the roots don't get too wet. I only grow them in chimney pots (so compost drains very freely) either side of my south facing front door (a very sheltered, warm location). I don't water them at all between September and April.

Last winter they came through unscathed. This year we've already had a prolonged spell of well below zero nights (and a few sub-zero days). That's put paid to them and yours may be the same.

You've not much to lose by putting them in the shed or garage. Cut any mushy stuff off, loosely wrap the roots and base in newspaper and check them regularly for signs of rot. Don't even think about potting them up or watering them until March or the first signs of new growth unless they are very dehydrated. 

Nanny Beach

We're east coast,my daughter who moved from Catford told me it's a lot warmer there! Too late for this year, but yes,shed, garage,pots wrapped, bubble wrapped in cardboard box,in pots of compost. Don't cut back, leave the foliage on till next spring. We have scented pelargoniums in our front garden, south facing near the bungalow,big,heavy concrete pots, they survived the beast from the east,-12 several days and nights. Tops were black and mushy, thought that was it, hubby re potted them. They were in flower last week,tops don't look happy,but we moved the pots,to clean the drive,so fingers crossed.

bédé

JoeX said:

I believe these are geraniums, not pelargoniums but I have forgotten how to distinguish them?

1.  Remember what your plants are called.

2.  Look up care instructions/

3.  Follow these.

Fairygirl

That's very unkind. Have you never forgotten to label a plant?  
I often forget which plant I have because, for example, I don't always remember the name of the variety. I also forget which group some of my clematis are in and I've been growing clems for decades in several gardens.
@JoeX is looking up care instructions by asking for it on this forum. 

bédé

2.  Look up care instructions when you first acquire the plant.

3.  Follow these from first to last.

WE all have problems with memory.  WE all ahev problems with labels.  WE have to cope.