in general ..... cutting off in spring ... is always the default ... then you know how far back the plant will die .. over winter ... leaves some winter interest .. and perhaps feeds the birds if seed is left ... its right up there with the theory of ... why do it in fall .... if i can put it off until spring.. lol ....

but then .. there is the psyche part of just having to have a clean garden.. or it will drive you insane all winter long ... do you fall in this group.. if so ... then yes.. you should clean it all up later in fall ... it is a bit early right now.. but i presume you are just planning ahead ...

ken

yes I am (panning ahead) but with these two perennials in particular are new so I want to cut them back at the right time the right way.

As SB says/implies, everybody that actively gardens figures out what works best for them in their particular soil and climate conditions, and given their particular tastes and preferences. Here, we have heavy clay soil that benefits from adding organic matter, and winters can be snowy but are often almost snowless for extended periods. What works for me is to cut down in fall plants with tallish stiff stems, and plants that can be disease-prone (e.g. Peonies) but leave lower-growing sprawly plants with minimal cutting back/just a tidy-up if needed. That way the garden looks a bit neater in its snowless stages but organic matter from the decaying low-growing plants gets added to the soil. If spring is particularly wet, I may pull decaying plant material away from the crown of the plants in early spring. So, in my regime I'd tidy up the catmint a bit but otherwise leave it alone until spring when it would get cut back to the new rosette of growth. The Helenium would have its stiff stalks cut down. Your preferences might be different, so decide what works best for you. Most plants are tough enough to survive a range of treatments!

I leave everything up for winter: bird food, critter shelter and traps the now in my windy back yard. I used to cut down my mildewed perennials every fall and they got mildew the following season. Since I stopped no different. Late season mildews don't affect their vitality.

I am somewhat opposite of Woody. I leave things with tall, stiff stems for winter interest. I remove floppy things so that there is not a mess to greet me in the spring. Lately, in either spring or fall, I have tried whacking the plants with hedge shears and then leaving the pieces to add to the organic matter.

I agree that peonies should be cut down in the fall, for sure. Watching their new leaves emerge is always a promising sign of spring.

I also agree that everyone has their own rhythm and rationale for their way of doing it. Nice that in many cases, it doesn't matter too much!

In my garden, catmint tends to seed around a lot if I leave it, and it's a mound of mush in spring, so it gets whacked back with hedge clippers to about ground level as soon as it looks like it's done for the season.

Helenium I often though not always leave for the critters to eat seed from, and I don't mind if it seeds around since the voles eat a few plants each winter, so seedlings allow for replacement. If it gets looking too tattered, I will cut it down any time that the snow isn't too deep, otherwise it's a really early spring chore.

I used to leave everything up for all of the reasons ken mentions, but then I volunteered in the NY Botanical Garden's alpine garden and got a different view. There, to my astonishment, we put a scorched earth garden to bed. Why? Because experience had taught the head gardener that it was impossible for him to present an attractive garden to the public when the doors opened in the spring.. There is simply too much to do then. i realized that my own garden looked like a construction zone until June -- not to mention keeping me too swamped with work to enjoy visiting other gardens! So now I too do as much as I can in fall and winter to prepare to enjoy the garden from the day the crocus emerge. The exception is not cutting back woody things like buddeias that need protection to make it..

Kitasei brings up a good point: a lot depends on how much you are willing to invest in cleanup next season, versus this one. I've done a few different ways, and what's working for me recently is to do the majority of cleanup in the fall. Spring is too mushy and mucky and indecisive (and I'm talking about me, not the weather!). And often times things are already growing through the old stalks if I haven't yet removed them, making surgery a little more difficult. It's mainly the stalks that I cut down - and I just throw them on the bed. Let the insects overwinter in them, but also for the seed heads - that is how I winter sow LOL!

A few Helenium pictures, last Friday..

The bees love this species selection.

Not seen any on 'Double Trouble'.

But they do seem OK with 'Fuego'.

While regional location and personal choice will have a lot to do with when one undertakes these tasks, there is an excellent source that outlines the optimum timing for much of this activity, at least for the cooler (below z7) areas of the country. And it should be a go-to reference text for any perennial gardener!! I'm referring to the Well Tended Perennial Garden by Tracy di Sabato-Aust. You can get used copies for next to nothing from Amazon.

Not only will this text describe the growth and cultural requirements of a huge range of popular perennial plants, it will give tips for siting and combining, when and how to divide or propagate and how to treat for winter, including when and how much to cut back. Pretty much an invaluable resource!!

Nice sneezeweed! Mine was hit by powdery mildew really bad this year and doesn't have much of a show. Yours look great.

Thanks. NM. Very sorry to hear that.

Was thinking we had the beginning of powdery mildew on a 'Siesta'. Haven't seen the disease in our helenium up to now. The particular plant's in a now largely shaded location, but all of the foliage has a uniformly (unhealthy?) look and there's no dying and falling of leaves at this point.

When I previously posted that we'd had a fantastic year for echinacea, I (of course!) had that area of your garden in mind. Suspecting your echinacea have been/ and are still looking good. As said, I was quite surprised to have David Tomlinson tell me that their echinacea had also done so well, while their liatris had not. Exactly our experience. As he said, the difference seems quite odd since both are tall-grass prairie plants. I'd also suspect that many of the echinacea we have have been bred further away from the wild type than have our liatris.

'Adobe Orange' is proving to be the best newer echinacea cultivar I've planted over the last couple of years. It's forming large clumps. Am hoping it's not going to grow itself to death.