Increasing the amount of soil on perennials

[WobblyLondoner]

I'm turning an existing border into a raised bed to help manage an area with dry shade - there will probably be 25 cm more soil on top of what is there currently.

I've got bulbs in there (allium) and a clematis (alpina), both of which I think will cope with more soil on top. But what do people think about the remaining contents, most of which have died back - do I need to dig them out and replant them or will they cope with adding more soil on top of them?

As I write this out I think I know the answer - which is not to be so bloody lazy and get digging - but if any of you wise folk think differently let me know!

Contents are -

Herbaceous geraniums, a few different varieties

A relatively newly planted star jasmine - jasmine tracelospermum - trained up the fence so a bit tricky to undo

A newly planted buddleia (I think this should be dug up)

Euphorbia robbiae - wood spurge - this is the one that will be a pain to dig out as it's deep rooted and everywhere.

If adding more than a top dressing of soil the plants will need to be moved otherwise you would be in danger of burying them.

Bit more info than you asked for - but if you know it already or don't need it maybe someone else on the thread will. Hope it helps :) o, and a caveat, I'm not an expert!

If I had the time, energy and inclination I would do this job now (or wait until spring),

I would do it in stages so that plants aren't hanging around waiting to be replanted while losing moisture. I would water in the plants well and keep moist for a few weeks.

As autumn is a good time to dig out and move these plants, I would move them after flowering and before frost.

Euphorbia robbiae send out underground runners, so I would dig out the plant and chase out the runners. I would wear gloves as the milky sap is a skin irritant.

For the Buddliea davidii I would reduce the existing growth to prevent moisture loss before replanting.

Allium bulbs cope best at least four times the depth of the size of bulb so I would check they were at about that depth.

Clematis alpina I would be trim back, lift, soak the rootball for a bit (an hour) hour and replant.

Geraniums I would lift and put into small(er) pots before the first frost.
I would take off dead, damaged and diseased foliage, and faded flowers, cut back by a third and put in a frost free, bright place. (I would take cuttings for more plants). I would do light watering until spring and then feed and increase the watering from spring onwards. I would plant out when frost is no longer a risk / danger (late May).
The Jasmine would probably need cutting back before moving and this may affect growth for a year or two but it should recover.

and then I'd wake up and realise it was all a dream and I was still on the sofa with a half drunk cup of tea on the coffee table ;)

Thanks so much @creideamhdóchasgrá.

I really want to do this in the next few weeks before it gets too cold, including planting back out - so nothing should be lingering too long. Really helpful.

Ps The geraniums are all hardy geraniums so assume no problem with planting back out immediately.

Its sounds like a project! and it seems like you've got it covered :) If you'd like some encouragement, I'll say, wrap up warm, radio on, flask of tea (or your usual tipple), gloves on and go for it! Happy gardening :)

O, and on the hardy geraniums, I would cut back but not too soon after flowering, and mulch with leaf mould or well-rotted compost or manure (as this will help keep plants alive and well for years if done annually).

Good luck with it all :)