Well on mine i cut the spent stalk to the leafy green part at the base.
Other people might do differently with theirs though .... we all have different ways of doing things, don't we ?
Which Veronicas do you have there ?

thank you for your help, much appreciated

I am not entirely sure which one I have as i am fairly new to gardening.

Have you still got the label that came with it ?
It's a good idea to keep hold of them so you can remind yourself of what you have in the garden, especially as you get more 'into it'.

yes i did think that - i definitely will in future - thank you for your advice

i usually dead head them in the hopes that they will give me another flower