Does this need dividing

Wildlifelover

I bought two Polemonium ‘lambrook mauve’ last year as 1ltr plants. One has formed a nice mound whereas the other one is double the size of the other plant and is rather bare in the centre. 

Does this need splitting? If so, should I do it now or in the autumn (it is almost in flower right now)?

 Many thanks. 

Fairygirl

Probably better to wait, although I often divide and move stuff when it suits me, rather than when the 'ideal' time is meant to be, even plants in flower. 

Polemoniums are pretty tough, so if you feel like chancing it, you can go ahead. If you don't feel lucky, then wait until after it's flowered 

Wildlifelover

Ok, thanks. I’ll probably wait until the autumn then. When dividing it, do I cut it back, dig it up, cut off the more lush side growth and replant those bits?

Fairygirl

Just divide and replant. Cut back a little if there's still a lot of growth at the time. It'll probably make two decent plants if the root system's good. No need to cut anything off, although bits will be damaged and they'll just die back themselves. You can just remove anything that dies off, and then let it get on with it   

Wildlifelover

Apologies if this is a daft novice question but I thought you had to discard the centre part and replant the outer parts?

Fairygirl

With most perennials, that isn't the case. Plants that grow in a circular pattern, where the centre gradually dies back  would need that - like Irises, but not things like Polemonium. The whole plant is viable  

nutcutlet

This is one that I divide after flowering, it seems to cope OK with that. and yes, keep the best bits and chuck the bald centre if there is one

Wildlifelover

Fairygirl said:

With most perennials, that isn't the case. Plants that grow in a circular pattern, where the centre gradually dies back  would need that - like Irises, but not things like Polemonium. The whole plant is viable  

Ah, ok thanks. How come the centre part of my plant has become relatively bare compared to the outer parts? 

Fairygirl

I find that interesting, especially with @nutcutlet's post too. I've never had that with Polemoniums 
If there's any dead stuff, then certainly don't plant that. 

nutcutlet

Fairygirl said:

I find that interesting, especially with @nutcutlet's post too. I've never had that with Polemoniums 
If there's any dead stuff, then certainly don't plant that. 

Lambrooke Mauve isn't like caeruleum etc. It's a sterile hybrid and has a different growth pattern, more like other hardy perennials that spread and die out in the middle.

Wildlifelover

Thanks both, all useful info for a novice like me! Any tips on how to go about splitting it as it’s something I’ve not done before.