Well I sowed some 2 autumns ago and they germinated that winter...so I don't think a long cold stratification is necessary...and moreover 10grams of this has just arrived from B&T World seeds so I will also be sowing this week - and I will be sowing direct (hence 10 grams) but also sowing in pots in the cold greenhouse.

However, germination is the easy part of raising JPW from seed - the absolute nightmare are slugs and snails - which will crawl through a gravelly hell to get at the seedlings. The only chance of bringing seedlings to maturity requires covering the trays or pots with either lids or fleece. My first effort of spring sowing was highly successful...but practically every seedling was repeatedly munched until most of them simply gave up.

Hardy perennial seeds can be sown at any time - even midsummer - they will germinate only when requirements are appropriate (which is why I never mess around with heat and light) and, if not this season, will simply wait in the soil until next. As long as soils are not continually waterlogged (rotting and pythiums etc.), seeds can be sown when you get around to it.

They did not like being covered by a layer of potting mix but fine grit was OK.

you might to duplicate this post in the winter sowing forum ... ken

Interesting to hear about germination ... I have a decent size clump which I let stand over winter for some interest... and it has never seeded down for me.

The 'best' method is going to depend on what you are trying to optimize. For something that is literally a weed, I certainly wouldn't put too much work into germinating them, but that's me. (and yes, they are weeds for me)

The seed starting Bible is Tom Clothier's database.

Well that is quite a resource! Not sure if this is the right latin name for my Joe Pye weed, but if it is it looks like I should be refrigerating it now before attempting to sow it this spring? Eupatorium purpureum , Sow at 20ºC (68ºF), if no germination in 3-4 wks, move to -4 to +4ºC (24-39ºF) for 2-4 wks

My experience with Joe-Pye Weed is the opposite of Nevermore's and more like Mad Gallica's - it sprouted everywhere if I didn't deadhead religiously, so I ended up removing it from the perennial border. I'd definitely be glad to have it in a wild area to enjoy with other garden thugs like Symphyotrichum/wild asters and Solidago/goldrods and Eupatorium perfoliatum/Boneset, but it has tenacious roots that made weeding it out a chore.

Ken's advice to check in the winter sowing forum is good. That way they will get whatever chill is needed and start growing at the optimal time. They aren't tropical plants, so the chill can't hurt them.

As an aside, the old name for this is Eupatorium purpureum, but the new name is Eutrochium purpureum, so depending on the source, you might find it listed under either one. I think this is one of those plants that was put into a different genus when the botanists started doing genetic analysis and realized that some plants may look alike as far as flowers and seeds, but not be too closely related.

I recall mine were listed as eupatorium maculatum??

According to the USDA/NRCS plantbase Eutrochium maculatum and E. purpureum are different species, but both used to be called Eupatorium purpureum. I wonder if the different species have something to do with how much it seeds around along with different garden conditions.

My records indicate that I winter sowed eupatorium rugosum on March 1, 2008 with germination on May 15th. Also, eupatorium 'Little Joe' on March 1, with germination on May 21 st.

I sowed Eupatorium maculatum (or is it purpureum ssp. maculatum?) 'Gateway' in my basement in March one year and it grew, you guessed it, like a weed.

tj

Unsurprising, Tsuga. Our native hemp agrimony (eupatorium cannabinum) grows all along the ditch in m y woods, along with rosebay willowherb (epilobium angustifolium)...so I am simply adding to the local weed diversity...and expect similar vigour.

Well, not sowing them...isn't going to make them grow either...so what do you have to lose? I'd cold treat in moist media in the fridge for a month myself, but it may not be necessary.

I know this is last year's post, but try winter sowing in plastic bottles. https://monarchbutterflygarden.net/winter-sowing-milkweed-seeds-checklist/

I did this last year with my Butterfly Weed as I wanted to know germ rate & where the plants were (we have city squirrels who dig up & move everything!). It's so easy, it's now my go-to method! 80% germ!!!