British Columbia: Experiences with portable greenhouse in Vancouver?

I want to keep some annual plants over the winter. Plants like geraniums, marigolds, impatiens, etc etc. I was thinking of buying one of those portable shelf greenhouses and putting it under the covered patio and close to the wall of the house. Is anyone doing this? Do you think geraniums can survive the Vancouver winter if put inside one of these? The one I am thinking of buying are the ones with 4 shelves and plastic covering. I think they call this cold frame. Thanks.

 

The impatiens will probably not make it -- they don't like temps much lower than 10C and turn into mush. But the geraniums probably will (they should be cut back hard beforehand) as long as it's a mild winter like the one just past. Don't know about marigolds.

My experience with portable greenhouses is that they have problems with wind. Make sure you tie yours down -- I lost one to a winter storm once. And make sure you don't ignore the plants in it. They need to be kept on the dry side but not bone-dry. Essentially with geraniums you're putting them into hibernation. If they get too much water they think it's spring. But plants that are too dry freeze more quickly than ones with some water at the roots.

Last, my experience is that plants rarely make it through an entire winter in Vancouver without needing some additional heat at some point. In a "real" greenhouse you can put up a string of those old incandescent Christmas lights (red, yellow and white only as they throw the most heat) and it will often do the trick, but I wouldn't try it with a (flammable) plastic version! You may have to bring the plants in for some nights.
HTH
keke

 

Hello yes I have 4 of these like 2m long 1 m wide ( not with shelves) I keep them over the yougn seeldings in spring etc. They have a tendancy to blow over. I found a way to near fully remedy
I tied one big plastic milk jugg with a string that is sitting in the middle of the bed with the string at its maximum stretch. but even with that they have blown over somehow with a strong wind.
If you manage to tighten all the air vents MAYBE you could use one of those flat pannel heaters that some people keep for dogs in dog houses etc.. ..Anyway from my 4 years of YVR gardening experience
its like playing the lotto .. so many things that are supposed to make it die and others dont. Why did my 5 year old in ground Gunnera die as it was supposed to be stronger as it grows older and was covered in leaves and layers of protective mulch etc.. One of my Bananas also died ad they others not...beats me.
I miss that "OUTDOORs warehouse" on Grandview avenue that was around still 2 years ( went bust) ago but they went bust at least they had "affordable" ( I guess too affordable) green houses made in China. I missed out on a 12feet by 8feet for 125$ that I was waiting to go on sale ..then the store closed.
Although the plastic seems to shrink in the sunshine and make the closing and openining with built in zipper doors near impossible. Had to add sheets of building top plastic to cover up. I think if you look in my pic from before they might be some there. Anyway Annuals are Annuals so I see not much point to make them become perrenials.
I am a REcycler and am building now an entire RECYCLED green house made of windows and wood from "freecycle.org" . Allow me to show off . Although with the awfull automn/ winter we had since last 8 month have not had the one week of sunshine needed to build it with DRY wood..