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I have various plants in greenhouse, lavender, penstemons, nicotiana, canterbury bells, that are quite happy, though not very mature (hence being in greenhouse) With the severe frosts forecast how can I protect the plants further. Limited funds.


most of them will probably be ok. It is the wet as much as the cold which kills plants. So keep them on the dry side. The nicotiana will Im afraid die as it is not at all hardy and normally treated as a half hardy annual.

You could improve the greenhouse by insulating it with bubble wrap, although I have had my unheated greenhouse for 10 years and find it more than adequate for most things. I am far to lazy to use bubble wrap


Thanks. Think I will move the nictiana into garage but very limited space for anything else.


One of the problems I have with the unheated greenhouse is how much water do plants need. I don't water when it's sub zero but when it goes on too long things dry out. Then if I water in a milder spell and another cold spell comes can they cope?

Having said that I haven't lost much over the years, mostly things that were never going to survive the cold even if dry. I just worry about them and feel guilty if they die.

Shrinking Violet

If it's particularly cold, then a roll of fleece is a cheap and good investment.  Just throw it loosely over the plants overnight, and that is usually sufficient to give the extra bit of protection.  (If you don't have fleece, then think laterally - I have used long-past-their-best sheets that are thin - mother would have had a fit to see me use them, much given as she was to the thrift of "sides to middle" repairs, but that's another story!).



My mum used to do that as well.

Thanks for that I have fleece, I just didn't want to go out and buy a large roll of bubble wrap, 

I just think I need to think out of the box

Shrinking Violet

Oh, Tinker Christmas Bell - it wasn't just my mum then!  And did you hate having the seam in the middle, digging in when you were trying to get to sleep?  And silently curse mother's thrift????  Oh, how times change - I guess there are many people of a younger age who wouldn't know what on earth we were discussing!

Anyway - good luck with the extra insulation.  I think you'll find that the fleece works a treat.  In the long term, bubble wrap is worth it imo, although it's a bit of a drag fitting it each autumn!


I used to moan like mad and then she discovered nylon sheets. In the end I refused to sleep in them so I had a pair of my own sheets.  Make s me shudder just thinking about nylon sheets.

I have moved a couple of plants ( the nicotiana)into the garage but the light is not that good, butthey will be frost free.

Thanks for help


flowering rose

Well,in my unheated green house I have put some plants begonias e.t.c.and I put black plastic trays round by the glass to keep the frost and cold away,.In the garden I covered some sensitive bulbs and plants with a big pot (it worked last year) and I put a black tray on sticks over my lavenders,so far so good.


Bjay- rolls of fleece arent that expensive & somewhere like Wilcos will be cheaper than a GC.You can layer up the fleece too.

Another investment, or pressie for you perhaps? is an expanding cloche, like a concertina, which can be made of either fleece or clear plastic. They can cost £20-25 & sometimes are on offer 3 for 2 etc. That way you can insulate/cover your plants that you want to overwinter by creating a sort of small poly tunnel inside your greenhouse without the 'faff' of trying to insulate the whole.

I've used some of mine for several yrs on top of large pots of agapanthus & a choc cosmos pot. In previous yrs I didnt even wrap the pots, but would always do now. Rarely lost anything in my very cold, exposed to East facing spot in NWest. J,

If you've got the space eg garage, you might find buying large rolls of bubble wrap & brown tape online a lot cheaper, even allowing for eg £2+ pp, & it soon cuts down to wrap around containers & green house.  We rinse it off/leave to dry outside in Spring/after the ice/snow & fold/store it to re-use this time of year.   We also re-use compost bags & large plastic bags if necessary to cover plants.  We're squirrels & throw little away - will never understand a throw-away mentality - that's why I love gardening - endless re-cycling 


you have given me such an idea Jo. I have a cloche type greenhouse it's about 1mx1mx1m I used it for broad beans last year. I could make that up and use it inside the greenhouse. It would work I think

Also we cluster outdoor/perennials together near the house wall, beneath an over-hang if you've got one, & place eg a garden bench or table in front so that although the light's reduced somewhat, with fleece/bubble-wrap/plastic wound around the pot bases or around the whole group a few times, they're protected.  Also leave a little of the surface soil around the stem exposed to permit moisture evaporation but limit water intake that then freezes & potentially damages roots.  It's a compromise but each year our pot plants: hebes, roses, magnolia, jasmine, fruits, lavenders, rosemary, bay, strawbs, hydrangeas, Japanese acers, other variegated small cuttings survive.  Do use unheated green-house which we stopped heating years ago because of mould problem.  Brought cuttings of pelargoniums indoors & mature pelargoniums cut back,cheese plant, succulents, cacti, cyclamen, agave etc into unheated sun lounge.  Hope this helps.


I'm planning on insulating my greenhouse with bubble wrap as we have got loads of it lying around (we moved to Brittany in April!!!) but I have no idea how you actually fix the bubble wrap to the glass. Any ideas and tips would be gratefully received.


nutcutlet. I face a similar problem with watering over winter, not knowing when or how much water to give plants.

Last year the plants were given a good bottom watering in October and it wasn't until about February/March time when they needed water. They were bottom watered again but as there's still chance of a frost I put less water in the trays and waited for it to be absorbed before taking a few plants out of their pots to see how far up the pot water had been absorbed, if it half covered the roots, I judged that to be enough, if not more water was added to the tray.

Sounds a bit pain staking but after nurturing plant through a cold winter didn't want them to die from over watering a few weeks before planting out, worked for me


Shrinking Violet

Re attaching bubblewrap in a GH:  you can get special clips from the garden centre that will hold the wrap to the frame by clipping into the channels in the aluminium glazing bars.  Hard to explain - but you press the clip (a sort of button thing) through the wrap into the glazing channel.  If you have a wooden GH then I guess you would use tacks of some description.

I re-use the bubblewrap each year, and the clips I've had for years.


Tinker Christmas Bell, I remember nylon sheets at a friends house; my hair stood on end with static as I touched them, but wouldn't they make wonderful plant insulation now?

All this info about over-wintering plants is very useful; I am in my first year with a greenhouse and am rather amazed at the amount of moisture in there and I haven't lit the paraffin stove yet, knowing that that is going to make it worse.

Shrinking Violet

Artjak - a GH is no different from your own house - you don't ventilate it regularly at your peril!  It's amazing how many people won't open a window in their house because they are "keeping the heat in" - and forget they are also keeping the build-up of moisture in as well - hence the likelihood of mould growth.  Likewise in a GH - even when it is cold, it does need ventilating, even if it's only for a brief spell, to get a change of air inside.


Thank you Shrinking Violet.

I spent  lot of money and time last year in trying to insulate our aluminium green house with bubblewrap. It's quite an old one, and the glazing bars don't take clips, so I painstakingly shaped it to the inside, like lining a dress, then fixed it in place with a combination of wire stretched across the green house and duck-tape. What a waste of time. Hardly any of my plants made it through the winter, I'd have been better off saving the money I spent on the bubble wrap and buying new plants in the spring! I did wonder if there might be any mileage in trying to stick the bubble wrap on the outside, but I guess the wind would tear it off. Half the trouble was that I couldn't get at plants to tend them. Anyone tried that?