Penstemon deadheading?

emsy.angel.22

Hello

My Dad kindly bought me some penstemon, I am wondering about deadheading them. I have been pulling the flowers off but they still seem to be going to seed and I wonder if instead I should be cutting the whole spike off? The only info I can find online is to do with pruning, not dead heading so any advice appreciated. 

Thanks

Mr. Vine Eye

Once the whole spike has finished flowering cut the whole spike back to low down, just above where there’s new growth on that stem.

emsy.angel.22

Thank you, much appreciated- I did think I was doing it wrong! 

Fairygirl

If you take the flowers off completely, you still shouldn't have seed, but taking the spike off  as described is the way to deadhead virtually every perennial.
It also means that plants can put energy into potentially producing more flower spikes