lost small plants this winter

Hi everyone,

Slowly my semps come back to life. A few need urgent replanting but most seem OK. Only, It looks like I have lost practically all small forms: octopodes, small arachnoideum and most pittonii. Small Jovibarba are mostly fine.

I think that this is because we had very little snow and not such extremely low tempertures but anyway freezing for considerable time. In this time the small plants simply dried out, watering didn't seem to make sense because at freezing temperatures the plants can't take uop water(ice) anyway.

How do you prevent water loss in small semps when you have say 4 months of freezing?

Is there any way to start growing the "leftovers" in a more protected environment like under glass, because I have some small stems with tiny leaves/rosettes left of some. These will probably not make it in the open air, I think.

Paul

Dear illustrator,

the topic of cultivating plants during the winter is very difficult.
This winter was very strange almost in the whole Europe. In the Czech Republic was the winter unusually warm, except one week without snow.

I do not know, how was the weather in Slovenia during whole winter. I only heard in television that were problems with ice in Slovenia. I do not know, if the weather changed during the winter (frosts and warmer days). If the weather changes so, there is also a danger of humidity. If the plants survive the winter depends also where are the plants placed during the winter. If there are in the pots on the stones, there is a danger that the frosts can the plants totally exhaust and the plants die. This danger is also in some on hotbeds on the legs.

Beware of S. octopodes, S. tectorum from the southern habitats, S. ciliosum, also S. marmoreum from the southern habitats. They do not like much humidity and they do not like also such conditions during the winter.

I place many plants in pots to the greenhouse at the end of the autumn. I bury the pots a bit to the soil in the greenhouse. The plants are there during whole winter and survive the winter without losses. You can see this way of cultivating plants during winter on pictures:

What is the temperature in your greenhouse?

I live at 750 m altitude and it gets very cold here at night in winter. This winter was not so cold, but -35'C is not exeptional ... This is no problem as long as there is snow ...

The ice has destroyed about half of the trees and most telephone and electricity lines in my region. Now landowners are busy destroying the forest in the name of "sanitation", people don't distinguish between economic damage and damage for nature. (For nature dead and broken trees are a blessing ...) The ice caused some superficial damage on the semp-leaves, not really an issue for our plants.

My plants are in pots which are halfway burried in the soil. There's (native) Primula flowering between the pots right now.

I live in Pilsen and in Pilsen there is warmer climate than in the nearby of Pilsen. But my garden is in the valley and there can be also frosts, but the temperature about -20°C are exceptional. The most common minus temperatures are between -5°C to -10°C.

There is no heating in the greenhouse, the isolation of the greenhouse is very bad. If the sun is shining, there is warmer (about 5°C warmer than outside). But if the sun is not shining, there is the same temperature as outside.
The pots in the greenhouse are almost fully buried, only about 2-3 cm of the pots are above the surface of the soil.

How tall pots do you use for houseleeks? Have you got any photos of the pots buried in the soil? Maybe there can be a problem. Many plants have not long root and their roots in the pots were above the surface of the soil. Maybe that is the reason of losses.
Were there any thaws with plus temperatures during the winter in Slovenia?

I will make some photographs in the coming days. There were many periods with thaws and daytime thaws last winter. It was really not very cold.

This was a very nice pot full of S. pumilum album. Many are still alive but I am not sure if any will survive.


In the middle is a large no-name cultivar. This plant is one of the "grow very fast - die very fast semps. I think that it will probably be OK, but it is a very big difference with last fall. I suspect that it has zelebori in it's ancestors, but it really is a no-name.



My collection, photographed today. In front (recognisable) S. calcareum, S. ciliosum and then some S. tectorum; all of these came through the winter without problems. They were uncovered, right in the open air, so they got all rain, some snow and all frost on their heads.

Illustrator, thank you for the photos. Now I can better imagine where and how the plant grow. If I see the picture with S. pumilum, I am persuaded, that the rosette died due to combination of moist and frost.


If the pots with the plants are a bit above the surface of the soil, there are two dangers.
1) It starts to freeze, the soil get freezed. Then the thaw comes - the soil above surface in the pots and in the nearby of the surface warms up, but the soil deeper under the surface is still freezed. Then the next period of frosts comes and the soil freezed again. The rosettes lost their roots in many cases (the roots decay). The rosettes do not survive the winter.

2) There is a long period with frost without snow. The soil is freezed. The frosts dry up the rosettes, the rosettes do not survive the winter.



I think, that the rest of rosettes of S. pumilum will survive. Give the living rosettes to the new soil, they will grow without problems.

That sounds plausible. It also fits with the kind of winter we had: a lot of rain and then nighttime frost.

I solved similar problems during winter 2011/2012. During this winter I lost some valuable plants (for example S. tectorum from the southern Pyrenees and some plants of S. marmoreum from Montenegro).
The plants of S. tectorum were in my hotbed during the winter. There is roof above the plants, but the hotbed is situated above the surface - "on the legs." The plants of S. tectorum were in the pots next to the polycarbonate. There were frosts - about -10°C, but during these days the sun was shining. The frosts dried up the rosettes.
The plants of S. marmoreum were in the pots outside. Befere the frosts there was thaw and it was raining. Then began the period of the frosts. Many rosettes in the pots lost their roots, because the roots decayed.