Not at all. I've been doing it for years, along with many other balcony gardeners. Instead of going to the lengths you do, I simply put the pots up close to the apartment wall so they get whatever warmth is there, mulch them 2" with western cedar bark mulch, and they do pretty well.

One thing bulbs hate is to be wet, so I mix a lot of perlite into the potting soil (Pro-Mix) I use. I mix in a little bone meal or bulb food, hang a wick from just below the soil line out a hole on the bottom to help wick excess water out of the pot, and set the pot up on bricks. That's it.

This year I planted tulips, asiatic lilies, la lilies, orienpets and muscari. That was the least of what I usually plant. All kinds of bulbs can be planted this way. I layer mine.

Here's one from last year {{gwi:4386}}

Thanks for the encouragement PG, particularly after I received a particularly extensive and unoptimistic post from someone else at another forum.

Its a bit late to add a wick now I guess but I could add mulch next time I unpack to check moisture level.

We've already had some pretty severe weather but I'll note your comments for next year's effort and just have to hope for the best at this point.

Seacat

What you've done should work this year. How cold does it get there?

We'll probably get the odd day or two each witner where it gets down to something like -27, but that's pretty extreme. I think that more common day time temps in coldest months, Jan-Feb, are in the -5 to -12 range.

We've recently been having some fairly warm weather with nite time lows in the -1 to -5 range but when I check the thermometer out on the balcony, the reading is usually warmer by a degree or two - it seems to be colder down on the ground.

How you have given the containers the protection you did should work....as long as the cardboard doesn't draw a lot of snow which then melts which then turns the cardboard to mush....never mind the bulbs.
As long as the containers can drain, the surface not freeze which takes temperatures down to freeze the bulbs before they develop roots, they will do fine.
Bulbs by the way, once having roots can take 40 below..and that's celsius or fahrenheit.

For our U.S. cousins, when Seacat quotes temperatures, they represent, when mentioning minus figures, that's minus from the freezing point....which is 32F.
The true formulae is ...the C. figure X 9/5....+ 32.
Since 9/5 is 1/5 away from twice the figure, we use that and subtract the fifth....or 10%.

To anyone wishing to convert...its simple...take the C..celsius temperature.....double it, (X 2) subtract 10%...which is move the decimal point, and add 32º.

The trick is to remember that 32 is always a plus number.
So if the figure such as minus 30....becomes 60...minus 6....= 54....now subtract 32 from it....that's 32 as a plus #. So - -54 subtract 32 = 22....that's minus 22 C.

Conversely, 10 C....double...= 20...minus 10%..2...= 18..
now add the 32º.....and that becomes 50 F.

There are two numbers in Celsius that can be just turned around....16 C is 61 F.....and 28 C...is 82 F.

Most temperatures are not exact...because in converting you end up sometimes in fractional figures. But, you're never much beyond 1 degree difference.
With numbers ending in 5.,,,and 0......the end result is always true.....30 doubled...= 60...minus 10%...6..= 54...add 32....86 F.

Many newer Canadians, never having to deal with fahrenheit temperatures are confused by people who still convert.
But fahrenheit does give a truer, more concise view of the weather. For most of our late fall and winter and early spring, the whole country is forever in minus temperatures.

This to me, weighs on the syche...always saying minus does leave a sour note in our wishing it to be milder.
Like last winter, it didn't start until mid January...I was golfing on this date last year....shot a respectible 85.

I think eventually the U.S. will join the rest of the world by using the metric system. It does in most scientific and manufacturing processes....only in temperatures does it hang on to the old ways.
And you too can learn to appreciate + numbers.

Re: numbers/temps
(thanks, very helpful - adds clarity to the old fractional formula).

Josh

I planted some on a balcony underplanted underneath an camelia tree , but I don't think they will do much I only get about 2 or 3 hours of sun a day and they just aren't going to bloom, oh well

That's all the sun I get on my balcony. I treat them as annuals, new every year. Gives me a chance to see a new combo every year.