Question
Hi there - I have a large balcony on the third floor of a buiding and would like to grow ivy on one side. My concern is having an annual survive Chicago winters. Do you think if I insulated a large enough pot it would work? thanks for your help.

Answer
Kelly,
I think that you want a perennial, not an annual. Annuals don't live through the winter, and I"m sure you want your vines to survive, as you say.  Here's the thing: plants in pots get 20 degrees colder than those planted in the ground, so in a pot you have to plant something that is every hardier than what you'd put in a garden. I'm not sure ivy would live.

In addition to that, ivy isn't really good for buildings. It clings to the sides of buildings using "holdfasts" and so the stems and foliage keep the sides of buildings damp, which can degrade both bricks and siding. It looks great, but isn't good for structures.

Would it be possible to attach a large trellis to the side of your building? If you could do this, you would be able to get a very large pot (at least 2 ' in diameter and larger would be better - wooden or plastic so it doesn't crack) and plant a Hops vine in it. Hops is fast growing and tough as nails. It is not evergreen, like ivy, but my guess is that you would enjoy it the most in the summer anyway.  The flowers on hops are very decorative as well.  

If the balcony is sunny (especially if it gets afternoon sun) you could plant an annual morning glory - they are very fast and bloom in late summer and fall. If you go this route don't fertilize as this vine blooms best in infertile growing conditions. Morning glories don't live through the winter, however.

Let me know if you need more information or suggestions.
all the best,
C.L.
www.wholelifegardening.com