Many spring blooming "ephemerals" have seed that must be sown shortly after ripening. A common feature of ephemeral seed is the presence of an elaiosome, a fleshy structure that attracts ants to carry away seed to their nests, the ants eat the elaiosome portion leaving the seed to possibly germinate. Some ant-dissemated seed include Jeffersonia, woodland Iris species, Epimedium, Trillium, many others.
https://en.wikipedia.org/wiki/...

All such seed is best to sow soon after harvest. Studies have shown that Jeffersonia seed needs to be sown promptly after ripening, then the seed flats go through a summer/fall phase of warmth, followed by a period of winter cold stratification, the seeds germinate freely the following spring. Epimedium seed is classic in this same requirement, so I sow all of my Epimedium hybrid seed in June after harvesting, they're planted in pressed fiber flats and left sitting in contact with the ground under the shade of trees; the fiber pots "breathe" and wick moisture, keeping moisture levels moderated. I lightly water the flats only in very hot dry periods, then they're left outside all winter, they germinate like beans in the spring. Note: all flats are covered with wire mesh to keep out chipmunks and squirrel digging.

I'm passionate about this subject, so allow me to share some examples:

Our native Jeffersonia diphylla, pods turning yellowish, the pod "caps" starting to unhinge to release seed, notice the white elaiosomes attached to the seed.


Jeffersonia diphylla seed, not allowed to dry out, can keep in plastic bag for up to 2 weeks


Jeffersonia seed in back row, I add dry vermiculite to the bags to absorb some of the moisture from the seeds and elaiosomes), bag of Iris koreana seed in the front, more about that one below.


Sowing seed of Jeffersonia (I think it's J. dubia seed), at its bagged storage limit where the seed has gotten very moist and sticky. I have always wondered what types of seed can be stored moist for long term, I noticed NARGS has moist-pack seed in the seedex; with Epimedium and Jeffersonia they rot if kept much more than 2 weeks.


In spring, seeds of Jeffersonia dubia and diphylla "come up like beans",
Top left is J. dubia, the other two flats are J. diphylla.


Seed of Iris gracilipes, among the most beautiful woodland Iris, the seeds are beautiful too. Seed matures early to mid July, need to watch closely because pods give no indication when they're ready, all pods shed in one day.


Seedlings of Iris gracilipes one year later, always get near 100% germination.


Seed harvest on our native Crested Iris, I. cristata 'Shenandoah Sky', seed ripens very late on this selection, at the end of August. Notice the familiar elaiosomes attached to seeds. Same seed sowing treatment.


Seed pod on woodland Iris from Korea, Iris koreana, split open and seed is mature enough. These pods give no indication when they're ripe, when it approaches mid June I break open a pod here and there to check. If one waits too long, all the seed will shed in one day.


Seed harvest on Iris koreana in 2016, a good year. This species is very shy with seed, most pods are not fertile, something bores into the pods and eats the developing seed, so I take advantage of the bumper-crop years. I think the seeds are beautiful, the white elaiosomes prominent in this species.


Very interesting thing about Iris koreana (and a sibling Korean species Iris odeasanensis, see below) is that they are "warm germinators". I sow seed immediately when ripe (2nd-3rd week of June), get germination in 6 weeks at beginning of August. In another 6 weeks, mid September, seedlings are big enough to plant outside and overwinter just fine. Here's Iris koreana seedlings mid September 2016.


Pods of Iris odaesanensis (also from Korea) are triangular shaped affairs on coiling stems half-hidden amongst the mats of foliage.


Seed harvest on Iris odaesanensis is more reliable and plentiful than I. koreana.


Iris odaesanensis germination at beginning of August, just 6 weeks after sowing.


Iris odaesanensis seedlings in mid-September, just 6 weeks after germination, ready to plant out to settle in and overwinter. I've had no overwintering losses planting out these youngsters in autumn.

As follow up to my initial post, here are some photos of the plants in flower, to round out the impression of the plants I mentioned, in case you're unfamiliar with them:

Jeffersonia diphylla, our native Twinleaf


The Asian version, Jeffersonia dubia (this is a special Korean form with red ovaries and dark stamens).


Woodland iris star, Iris gracilipes


A favorite crested Iris selection, I. cristata 'Shenandoah Sky'. A patch of Japanese Ariseama sikokianum behind.


A mature clump of Iris koreana, a wonderful woodland Iris that flowers at same time as crested iris here.


Another Korean iris species, Iris odaesanensis, a nice white-flowered woody species.


Many of these choice woodlanders, including the two recent Korean woodland iris, are available from Garden Vision Epimediums:
http://www.epimediums.com/

Korean woodland Iris odaesanensis was introduced into cultivation in the USA by plant explorer and Epimedium guru, Darrell Probst, and made available through Garden Vision Epimedium nursery.

Originally only known from Mount Odae (Odaesan) in Korea, in that area the flowers have a bold brown halo around the yellow signal patch. Darrell discovered additional colonies of this Iris approximately 100 miles away on Chuwangsan, extending the range. Three different clones were selected; these lack the brown halo around the signal patches.

Left: Iris odaesanensis Chuwangsan #3
Right: Iris odaesanensis (collected from type location on Mount Odae, Korea)

Welcome! Boy I want to hear more from you (and see more too) this is great stuff!

I have some Iris cristata 'Abbey's Violet' I got from Edelweiss Nursery. They have proved to be quite tough and cute, and I was hoping to get some seeds. Never could find any. This year I will try using the little net bags I got, and sow fresh in a pot and put it under a shrub.

I have done this with some other species. The hardest for me so far (That I have actually gotten to germinate) is Iris foetidissima, which germinates here during the second winter, sown either fresh or dry. I even did a little experiment with how I cleaned the seeds out of the berries. Interestingly, I got some germination no matter what I did, but the best was just to plant the berry!

Thanks Mary I do play around with seed and experiment with various techniques. Last October I did a 3-city speaking tour in Salt Lake City, Denver, and Santa Fe, my talk is called "Garden Lab - Seedy Experiments - Part 1", designed to illustrate the benefits and challenges of working with seed. I'm working on Part 2 now, for a local talk in March, this time it's about hybridization.

I like the idea that you too did some seed experimentation, so much can be learned, and plants that are otherwise hard to propagate can be increased dramatically via seed. I've done similar experiment as you report, but with Arisaema, sow the whole berry or kernel (has multiple seeds inside), or do the messy cleaning job to extract seeds, I get germination both ways.

In 2013 I ordered some Epimedium from Edelweiss Perennials, beautiful healthy plants sent; I also ordered a couple Iris cristata 'Abbey's Violet'. They turned out not to be true, got a regular blue cristata and a white one! I just ran outside to check my labels, verifying the year they arrived here, had to tease the labels out of frozen ground to read them. So, I'm still looking for the true plant.

I also got my Iris cristata 'Abbey's Violet' in 2013. I never looked closely at them, but superficially they look to me like the advertisement, they are a pretty purple. I bought a lot and they are all the same. This spring I will try to get a photo and send it to you to see what you think.

I suspect with berries, if it is something that sprouts very slowly, even if there are germination inhibitors in the flesh, over time the berry rots and it all diffuses away with the rains, and maybe even provides some nutrition for the seed over time. I see the berries lying on the ground under the iris, nothing here seems to eat them, so they will likely eventually sprout. It sure is easier to just plant the whole berry rather than scrape off the flesh.

Mark, this is very interesting and informative. I haven't had much luck with seed sowing, and that is with trying things that are "easy". I would love to try and have success with something like Jeffersonia, but it seems quite complicated. It is a favorite that I would like to have en masse in my woodland, but it is hard to find in the market. We have three native plant nurseries that I know of that sell them and are what I consider within local distances, but each plant is expensive. I bite the bullet and pay upwards of $20 per plant for single things that I want to add to one of my collections, but I just can't justify paying those kind of $s to get a specific plant in quantity. I know growing them from seed is about the only way to achieve it.

I have a single plant of Jeffersonia diphylla that I purchased at a native plant sale last spring. I've been looking for signs of re-emergence and haven't spotted it yet, but it is early still. If it managed to survive, I'll try to collect the seeds this year and give it a try. It will definitely be on a small scale with only one plant, but it could get my feet wet on the attempt. You explained the "how to" well.

My friend @greenthumb99 is much more accomplished at seed starting than I'll ever be. I met him and his wife Pat online through Dave's Garden, Dave's first gardening website before NGA, and then was thrilled to see that they live in the same small village that I do. Funny to meet someone out in cyber space that lives a mere 5 miles away. They have similar woodland conditions. David, I know you'll love this thread and the topic. It would be nice to have some action in the Shade Gardening forum

Terri, I use this photo in my talks because it speaks volumes about the possibilities, and the paradox regarding high price of Jeffersonia plants. Yes it takes a number of years for a Jeffersonia dubia plant to bulk up in size, but once you have a mature plant, look at the crazy number of pods it makes. From this one plant it had well over 100 pods, each pod will have (depending on size of the pod) 10-30 seeds inside, so using average 20 seeds per pod, the harvest from one plant is easily 2000 seeds!

Jeffersonia dubia (Korean Form) with seed pods, May 25, 2014


Seed are sown in pressed fiber flats as soon after harvest (can't allow them to dry like regular seeds, that'll kill the seed). Cover seed with thin layer of soil, top dress with spruce needles or decomposed bark mulch, cover with wire to protect from varmints, sit them on the ground in deciduous tree shade, forget about them and they should germinate like beans in spring. During summer, I do sprinkle with hose or watering can during hot dry periods.

Growing Jeffersonia can be compared to viticulture (wine-making), every year a single Jeffersonia plant can produce 2000 seeds, one gets very high percentage germination, repeat each year for 5 years, one could have 10,000 plants in differing stages of maturity. It would be easily possible for a nursery to produce Jeffersonia at much lower cost.

I also have photos of 5-year Jeffersonia dubia plants with all soil washed off, to illustrate why this plant can't be divided, only viable method of increase is via seed & patience. I'll upload those photos later.

Wow! I was thinking that with only 1 plant, I'd only have a few seeds, never would have thought it would be anywhere near that number!

Terri - thanks for alerting me to this thread, and Mark, I appreciate your insights into propagating J. diphylla. I have a small patch that I intend to use as a seed source. Last season I missed the ripening of the seeds, but hopefully the event this year will not coincide with my other knee replacement. Plan to follow your instructions and germinate as many as I collect. If successful, I will share some starts with Terri, who is way too generous with her assessment of my seed-starting prowess.

Hello David, thanks for your comments, it's been quiet around here but I think perhaps that's due to the fact the season is so late this year, still like winter hear in New England. Hopefully with your health cooperating you can collect some seed (watch it carefully, seed sheds very quickly with little notice when it's ready), and get some seedlings going, they're wonderful plants.

Thanks so much for posting this thread. Great information! I'm trying to increase my woodland plants as I clear space on the ground for them. Have only been dividing. Will try to spread to new locations via seed, too, and see if I have any luck

FoolOnTheHill said:Thanks so much for posting this thread. Great information! I'm trying to increase my woodland plants as I clear space on the ground for them. Have only been dividing. Will try to spread to new locations via seed, too, and see if I have any luck

Thank you Chris, glad the information is useful. I'm uploading a few photos to show why plants like Jeffersonia dubia cannot be easily divided and are best grown from seed.

This is a 5-year plant of Jeffersonia dubia from seed, for such a delicate looking plant it has a strong well-developed root system. In the photo on the right I have indicated the ground line; looking at the plant in the ground one gets the impression there are multiple growth point thus can be divided.


These two images also show a 5-year old Jeffersonia dubia, but in this case the plant died for some reason. Looking at the close-up view one can see the apparent multiple growth points all boil down to a single primary tap root, which can't be divided. If trying to divide old mature plants of Jeffersonia dubia the mortality rate of divisions will be very high.

Good to know! I don't have any twinleaf right now, but I do love that plant! I had just put some in our yard in Columbus before we moved. First time I ever grew it, and didn't grow it long enough to even think about dividing it.

Your plants are so healthy and beautiful!

Chris, I could imagine Twinleaf (Jeffersonia diphylla) on your newly cleared wild woodsy areas you showed in another thread. Once they get established they take care of themselves, they are tough and tolerant of dry shade, flowers don't last long but are delightful in spring, but make impressive foliage masses for the rest of year. Besides, it's cool to grow either of the two Jeffersonia species, a genus named for the great Thomas Jefferson. I usually get more than enough seed of Twinleaf each year, I am happy to share some when it's ready in early summer.

That sounds great! I don't have a specific design in mind -- it's evolving as we go. Getting what I can for now, as I have a lot of area to fill in!