help to identify and how to grow more?

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Thanks, the options were not there on my mobile. Here it is...

Erysimum bowles mauve

Wallflower Bowles Mauve, a real good doer. I successfully took 20 cuttings last year with help from other posters

Thank you both, can you give me anymore information on:

When to take cuttings

How to take cuttings (I am new to this)

Any other information I could need to ensure successfull groth of new cuttings.

Cheers.

First I mix 50% grit and compost, then look around the edge of the plant for small shoots that you can peel off. Remove the bottom leaves and the tip. Put these around the edge of a pot (terracotta is better but not essential). Cover the the pot with a polythene bag. Make sure the shoots stay moist and check for roots after a month.

I struggled at first then suddenly they all started to root.

You can take the cuttings now.

http://www.gardenersworld.com/how-to/projects/propagating/how-to-take-summer-cuttings/323.html

This is the official version

I've just planted some of these, are they reliably hardy (West Sussex), or should I be taking lots of cuttings instead?

They're flowering beautifully already. 

Hardy-you will be ok

-they do get a bit straggly and woody after a few years-that is the time to start taking cuttings.

Ah great, I have a while to practice taking cuttings off them then! Thanks.