Propagate from cuttings

Sarah Raven says this verbena should be propagated from cuttings rather than seed...
http://www.telegraph.co.uk/gardening/3394800/Sarah-Raven-on-Verbenas-Autumn-lights.html

...easy to propagate from cuttings. You can take them almost any time if you have a frost-free place to store them through the winter - and they will readily root. Snip off some burgeoning side shoots about 2in long, push into a gritty mix of compost around the inside rim of a small pot and root with a bit of bottom heat. When you see roots come through the holes in the bottom, pot them up individually and store them somewhere bright and frost-free (a sunny window ledge or cold greenhouse) for planting out late next spring.