Penstemons Stopped flowering

EmmaP2

So this year my penstemons have been rather lack-lustre in the flowering department.  They all have lots of leaves and look healthy, but instead of lots of spires of beautiful flowers I have got one or two.  They are about 3 or 4 years old - should I be dividing them (and if so when) or should I start again??  thanks in advance.  

Fairygirl

Dividing perennials is necessary to keep them thriving. They're at the right sort of age now. You can do it when they're dormant - autumn, or in early spring when they start into growth. It depends on your own conditions as to which is more suitable. If you do it in autumn, you can end up with a lot of small plants, and if you're in a colder, wetter part of the country, they're a bit vulnerable if planted back out in those conditions. In spring, they stand a better chance of thriving. You can still do them in autumn, but keep them potted up to grow on for planting out next year. You can also take cuttings from them to give yourself more plants, should you want to do that.

The existing plants might have benefited from a bit of extra feeding if they've not been flowering terribly well. Perennials need a general feed - ideally in spring, and a good mulch of rotted manure or good compost is also beneficial. For heavy, prolific flowerers, you can give them an additional liquid feed later on to help prolong flowering. Something like tomato food is ideal. Deadheading regualrly also helps to encourage more flowers, if you have time to do that  

EmmaP2

Okay Thanks - I mulched all the beds with mushroom compost in early spring this year - so I think they have had enough food this season - and I deadhead regularly - so I think that we might be at the needing to divide stage - which is what I thought might be the case.  I am in South East, so might be able to get away doing that in the autumn.  I don't have the space for a green house, so tend to stay away from cuttings - because they need a bit too much TLC.  Thanks for your response.

Fairygirl

That's great Emma - it really does depend on your own conditions.

Up here, the season's shorter, so I tend to divide plants in late spring/early summer - as the ground doesn't warm up quickly. I could split plants now and replant, which might mean forgoing any late flowers,  but any later and it would be best to pot up till next year as the ground's cold and wet. If you're in the south, the conditions are more favourable, so it means you have more choice for doing these jobs  

I know what you mean about cuttings - it can seem a good idea, but if you don't have the time or the facility, it's not always useful. I end up with lots of little plants tucked in the borders, or in a sheltered spot somewhere, and then I forget all about them. Usually nowhere to put them either!  

Lyn

Mushroom compost may not be the best thing for them, not all plants like it.

heres what Monty has to say.......

Adding masses of mushroom compost to the garden, year after year, results in an impossibly fertile soil. Stop mulching, says Monty Don, and let the space invaders return.

susieblue-1

This is helpful as had same issue. When and how should I cut them back? I've only had my plant a year, should I split it as you advised? New to gardening and no greenhouse or anything.

Fairygirl

Hi @susieblue-1 - people have responded on the other thread you posted on