Deaths

A few of my cacti have died this winter, including two large ones many years old. I can't understand why because they haven't had any different treatment from other winters, and it isn't vine weevils because they are still sound in the pots and I gave them vine weevil treatment last year as I always do. They just seem to have rotted away.
Some small ones have also died - just rotted away.

They are in my greenhouse, and it has walls on two sides, and the other two sides have short walls with glass on top, but I wonder if it was too damp in there. I did open the windows on dry days but a lot of condensation gathers on the roof.

I feel sad when one of my cacti die. They're my friends and I prefer them to people.

They need repotting, so maybe that's the thing ...
but I don't know when I'll get around to it.
Anyway, I've watered the live ones and I think there are so many of those that there's enough to keep me going.

I saw a lovely one in a garden centre last week but I didn't buy it. It had buds on it too, but I decided to leave it in the shop.

 

Wet soggy winter with high humidity, just what they dont need Micheal.
I've noticed that with larger ones they often form condensation on them if the day warms up after a cold night, the plant body, being mostly water, stays cold but if the temperature rises it forms condensation on the plant.
If the humidity is high it cant dry before night and the cycle starts again next day.

My old greenhouses that still holds the remains of my collection are left open on all days above zero, but often its so damp outside nothing dries.
Almost like alpine growing apart from trying to keep them above zero slightly overnight.

 

Thanks @pete, yes I think the dampness had a lot to do with it.
I have a dehumidifier I was using in the shed. Perhaps I'll put it in the greenhouse next winter. It may help a bit.

 

Was your Euphorbia Millii in the same place for the Winter?

 

I think running a dehumidifier in a winter like the last one could be like trying to hold back the tide.
To me, if the temperature inside is the same as outside you can stop a lot of condensation actually forming.
Last winter wasn't cold, but it was very damp.

 

It was in the greenhouse until the leaves dropped off in about November, and then I brought it into the house. I didn't water it until recently so was surprised to see the flowers.
It's back in the greenhouse now.

 

The greenhouse is usually warmer than outside. The roof seems to get a lot of condensation. I could try to put some bubble wrap under it.

 

The condensation forms because its warmer than outside, which you need on frosty nights, but during the day I think you need total ventilation if the temperature is above freezing.
The wind blowing through is good.

I think you have twinwall polycarbonate on the roof if I remember correctly, which is in itself some insulation.

 

Yes that's right, and I thought maybe that's why there was so much condensation. Not sure about that now though.

Bubble wrap wouldn't help then ?

 

Bubble wrap might help, but so would ventilation, you might trap condensation between the bubble wrap and the roof.
I've got twinwall on my greenhouse roof and my back porch roof.
It does get condensation overnight but I try to open up most days to dry it out, especially mild windy days or sunny ones.

 

I'll just keep on with ventillating then.

 

It is disappointing when plants die. I think you should go back to the garden centre and see if the lovely one you saw is still available and waiting for a good home, @Michael Hewett.

 

Maybe I will, maybe I won't !
(but I probably will )

 

Place your bets please! Will Michael be seen on the "Show us your purchases" thread shortly?