What to put in balcony window boxes.

I have 12 ,18" window boxes around my balcony which every year I've planted with geraniams. I've never managed to keep them through the winter so buy in new lots every year. This year I've decided to put something else in the boxes, maybe something that will be more permanent as the cost to constantly replace them is quite high.:(
Any suggestions? Bearing in mind our temperatures are from - 12 to 35 deg.

 

Perhaps something like box hedging? Nice and slow growing. Euonymus if you're happy to trim it, or heather, lavender, hebe, skimmia (Skimmia 'Rubella' is particularly good in containers).

 

You could try something which will trail itself up and across your balcony.

Two clematis in complimentary colours would transform a balcony. You could have months of flowering.
As long as you shade the roots, they should do ok

Are you giving up on annuals altogether? Annual climbers- sweetpeas and black eyed susan seeds would be fairly cheap.
Also California poppies look great in pots, especially if you sow in succession.

 

Hi Mandy

Like you have had, I have the usual Geraniums in mine ... but I rarely get below zero let alone your -12c ... horrors! Having a think, what about variegated Ivy or Nepeta for year-round interest (I have some trailing out of pots on either side of my front doors) and put a few heat-resistant colourful plants in for summer interest?

 

Thanks for all the replies. I think I'll end up with a few Ivy or Euonymus plants and something flowery for colour in between.