Are autmn/winter-flowering wallflowers suitable for planting in windowboxes-height approx. 30cms??
Autumn and winter flowering wallflowers tend to be shorter in height than the spring flowering types, so you should be fine. They can continue growing and flowering come spring time, so they will increase their height a little, but overall they do tend to grow to around 18′ or 45cms. I’m assuming your 30cms is the soil depth, which will be fine for these. Hope this helps. Good luck!
