Heleniums

I believe neither of these plants like damp conditions in their soil, so I would wait to plant until next year.
I'm by no means an expert, maybe it depends on the type of soil you have.
I've never grown heleniums, but we have a row of salvia grahamii next to our terrace, and they thrive in dry conditions. Planted in spring.

ps I've just looked up salvia g. and it says you can plant it in autumn in well drained soil.

Any plant that I’m dubious about I overwinter in the greenhouse, then come spring when it has started to grow I wait for frosts to go usually Mch-Apl here and plant out.

Great thanks for that.I have an unheated greenhouse so I will pot them up and do that.How often should I water them ,just enough to stop the compost drying out ,say once a week ?Still a bit of a novice !The bed they are going into is not the driest but neither is it too wet.And I intend to try Nemaslug treatment in March to give the plants a chance.

I love this time of the year because our local nursery has an autumn sale so I fill the boot with loads of perennials, pot them up then leave them to overwinter in the greenhouse or cold frame although most of them are perfectly OK to stay outside.

The bonus is that next spring they should have put on enough growth to split them.

Just prevent the soil from drying out with a little watering now and again.

Just what merlot says! They will be lovely next year - enjoy!