Advice needed for protecting plants at altitude

Hi everyone, I live in the French Alps at 1450m altitude (over 4750 ft).
In the winter here ( which has just started with our first snow) we have fairly extreme temperatures and although it is still not too cold it is likely we will have temperatures around -20c ( which I think is about -4 farenheit) by December.

On the other side because we are fairly far south, summer temps are hot! I have a fairly new garden and have planted several flowering bushes - all chosen for their ability to withstand cold and frost. Howeverm last winter I lost a couple of bushes and 2 others appeared to have died but then came back as new shoots from the roots. Naturally - if I carry on like this, these bushes will never get any bigger as I will always just have one years growth! I have bought large frost blankets that allow the plants to breath and I have mulched with bark to protect the roots. My question is when to put the blankets on? I thought I should wait until all the leaves fell, which will probably be another 2 weeks as they are only just turning now, but now I am wondering if I can do it now as we had snow two days ago, though it has cleared now, but quite a frost last night. Will it hurt the plant to cover them now? I don't have time to keep covering and uncovering in the winter, so when the covers are on they have to stay on as I run a ski lodge and I'm also a ski guide, so the garden is under snow and on the back burner until spring! I would be grateful for any advice.
Thanks! Emma

 

Thank you for that - the sun has melted our snow now and dried everything nicely so I am off to cover everything up!

Emma

 

I would agree with Marley. A fleece will let some light through and is porous enough to allow your plant to breathe. I suspect that it will do them no harm to be covered now.

In the winter the fleece will be covered with snow, and I suspect that this 'Igloo effect' will keep the plant relatively warm. Its different in the UK, when it can be very cold but we have no snow cover. I suspect the blankets don't work quite as well.

Don't worry about the young plant dying back to ground level. If the plants really can stand those conditions they should thrive. As plants get older and woodier they can stand colder conditions. In the first year the plant has little root, so it is very vulnerable and not able to grow very big during the summer. But this year the roots and topgrowth will be bigger - and then even bigger next year. When the topgrowth is big enough it gets woody and shouldn't die back to the roots.

 

Well, Emma, aren't you lucky to live in the French Alps!

You've had, as always on this forum, very good advice. I would only add, what do your neighbours do? I've always found it to be instructive in a new area to have a look at what's growing in neighbouring gardens. And gardeners, as we all know, are always pleased to be asked for advice.

Lorna

 

Yep I think you need to be careful what you plant, It appears you get extremes of temperature so you really need to pick what you plant very carefully.

I dont really think frost blankets are likely to be very effective during such winters and you can only plant bone hardy shrubs.

 

I'm just thinking that minus 20C is more than most of us are used to, and if a shrub needs protection at this time of the year its obviously not likely to take minus 20 later on.

I'd tend to go for shubs that originate in N America or Northern China, Siberia even.

Dont think its comparable to a UK winter summer regime.