Garden Fleece - How the heck..?

Pretty chilly for the next week or so . Just loosely covered my Cordylines with some garden fleece. Now I have used this for years . But if I put a coat on it keeps me warm , as I am generating heat and the coat insulates me. But how does does fleece keep a cold plant warm , where is the energy it is conserving ?

 

It works against radiation frosts, the sort caused by heat loss when you have clear skies, just by keeping a bit of residual warmth in.

Wouldn't work with a good old minus 10 arctic blast though

 

Well @HarryS if you have your Cordylines in the open ground especially if it is South facing then there will still be some residual heat coming off of the ground and even if you have the plants in pots the soil or compost might have heat in it although at this time of the year it might be a little bit or not a lot.Your Cordylines are a living thing so they probably give off a little heat themselves through their leaves if they manage to get any sun on them even in the winter months,but then again I might be waffling about things I don’t know anything about

Also a lot of plants come from countries where the winter temperatures don’t drop down too low so if they are grown here and the frosts get to the crown of the plant and attacks the plants cells then that can destroy them and the plant.Some plants seem to produce their own antifreeze like evergreens in their plant structure so they can tolerate extreme cold

I have an agapanthus growing in a gravelly border on a west facing house wall and this plant can survive the winter months ok because any sun that manages to warm the wall up radiates it back out onto the plant roots and it survives ok.Many of my other Agapanthus plants are in the greenhouse all snug and warm.Any that I have left in the borders other years have perished

 

Fleece can work to some extent, but for me it is mainly useful for late spring frosts rather than winter humdingers, think I mentioned I had problems even with a light spring frost when the fleece was actually touching the plant.
I look at it this way, as long as temperatures rise above zero during the day for a few hours it can be of benefit, as you are preserving warmth for that bit longer over night.
However, during an arctic spell of subzero temps. I dont think it can do much.
In fact if left on during mild days it can actually retain the cold longer.

I protect some plants, been doing it for years, the BOP for instance and I use blankets, but the plants are growing against a house wall with heating on the other side,, the blankets trap that heat.

As a sideline, I tend to ignore those stupid windchill temps that we are bombarded with these days, they are total fantasy IMO when it comes to plants, plants produce no heat, so are the same temperature as their surroundings, so "windchill", "feels like", and all that rubbish has no bearing.
Having said that, a strong wind when temps are below zero does help the frost to penetrate faster, but here in the UK we dont often get sub zero winds, well not round my neck of the woods anyway.

 

Winner of GC's word of the week

 

Indeed! Now we just have to figure out which BOP Pete is actually wrapping up. What a thrilling quest

BOP Bow of Peril (Lineage II; video game)
BOP Brotherhood of Pain (gaming clan)
BOP Block of Packets
BOP Byte-Oriented Protocol
BOP Brotherhood of Pwnage (gaming clan)
BOP Binary Oriented Protocol
BOP Boring Old People
... and some more

 

Knowing Pete, it might be breach of peace

 

I read the other cordyline thread and refrained from offering my experience but, as a second thread has come up I'm going to throw in my tuppenyworth anyway.

In my last home, when I moved in, there were several plants in pots. One of which happened to by a cordyline (the red one). Mr "M" in his usual put-the-coal-on-upside-down fashion dumped it in the copse end of the garden (because the pot was broken! ). Worse, he dumped it upside down! Twitty!

Anyway, that year we had one of those rare heavy snowfalls - this means the plant and its roots were exposed, then hidden, under that snow. As it was in a quiet part of the garden, I just left it be - it was a big garden and there were other, far more interesting things to be doing. That next Winter? More snow!!

The year we were packing up ready to leave and move here ... that neglected, upside down cordyline (the red one) which had been given NO love, care, protection or indeed, any notice whatsoever for 4 years ... drew my attention because ... the little beggar was growing!!! At the time, I meant to take a photo and post it on here, but never got around to it. I've searched my photo files and cannot find anything to prove what I'm saying is true - you either take my word for it, or not, as the case may be. But, no one was more surprised than I was!!

Take from that what you will but that was my personal experience with a cordyline (the red one)

 

BOP, bird of paradise.
ie, Strelitzia reginae.
Cheers

 

We knew that Pete, but it's winter and we needed some fun

looks warm in Kent

 

Interesting Pete, though I'm not totally convinced (yet!) that plants produce no heat. As far as my little and shinking brain understands, unless there is 100% efficiency in energy conversion into growth some energy will be lost and released as heat. And the heat will be stripped faster by air that gets warmed and then moved so more air can be heated and moved from the plant.
From the 'human bean' aspect, I do know that the passage of air does strip heat and reduce body temperature. I was out on my bike last week in 2C, but windchill was quite apparent the faster I rode.
A very interesting topic and worthy of more well informed and experiential responses.

 

My garden has seen -3°c twice and -2°c a few times this winter in the coldest spot. Due to lack of space I have this little huddle of plants that are either expendable or I know will not be killed by serious cold...............


This huddle includes

• Brugmansia sanguinea
• Canarina canariensis
• Echeveria agavoides and pulvinata
  
• Gibasis pellucida
• Kalanchoe diagremotiania
  
• Miltonia orchid
• Salvia gesneriiflora
• Tradescantia purpurea

Apart from the first minus three they have remained outdoors under the more rigid, less see through bubble wrap sheeting. The flower buds which are forming on the Brug and Salvia are undamaged and the Canarina continues to bloom. The Tradescantia foliage which was resting on the ground got frosted but all the other plants appear fine. What I am assuming is that the bubble wrap retains a bubble of warmer air that radiates from the wall and that it does it better than fleece would (with the added advantage of being waterproof). I think that fleece is better in the spring closer to the ground where it will help to retain heat that the soil may have built up during daylight hours like Pete suggested. I've also used fleece in an unheated greenhouse alongside hot water bottles.

 

I thought that the damaging effect of 'windchill' is more to do with dessication than actual cold?
During our awful winter of 2010/11, even though the temp varied between -12C and -17C for 10 days, there was a layer of snow which, as with alpine plants, protected them rather than killing them.....
@HarryS ....Isn't the principle with cordylines to keep moisture out of the crown of the plant? They'll stand dry cold but the growing point is susceptible to rot. A neighbour in Northants had several 15' specimens in his front garden which he tied round with string in winter so the rain ran off. No other protection.....

 

As I said, below zero winds do make frost more penetrating IMO, but mostly, and I'm saying this reservations, wind helps to stop frost forming, and temps dropping as low, as under a totally clear still night.
I agree with @noisette about the desiccating effect of wind on plants, but that mostly comes into play during exceptional circumstances, when the ground is frozen and the roots cant extract moisture.
I do agree under Arctic conditions things are different.

As to wind chill, I'm not convinced a plant produces heat, my greenhouses are stuffed to the roof with plants at this time of the year and it is as cold inside as it is outside if I dont use heating.