Harvesting woodland seed: Iris koreana and others

Submitted by Mark McD on Wed, 05/26/2010 - 21:24

I've never had good luck harvesting seed on Chinese Iris species, or even the North American woodland Iris such as Iris cristata. It helps being retired (wish I was) or unemployed (wish I wasn't, sort of), because I get to observe in much more timely detail, about what plants are up to. Year after year, I see big, fat, 3-sided pods on species like I. koreana and I. odaesanensis, two wonderful Chinese woodland Iris species, but rarely ever get any seed, although do find seedlings of I. odaesanensis often enough.

So, I discovered that the seed pods are much like other ephemeral seeders such as Jeffersonia, Epimedium, and Corydalis, they are actually ripe and mature when they're still green, when they are "al dente" and not "fully cooked", but even moreso with I. koreana. Harvesting the large seed pods while green (noticing that a few had gone over to yellow, but with nothing inside), and snapping the green pods in two, there's good seed in there, like golden kernels of corn with starchy appendages (elaiosomes) that are attractive to ants.

So, I harvested seed on Iris koreana, odaesanensis, and henryi much earlier that I would normally, and found a good percentage of viable looking seed. Time will tell whether my early seed sowing efforts are the proper recipe for success. I checked some green pods on Iris cristata today, and while the green pods had developing fleshy seed inside, it was too early for them... but I shall keep checking.

Comments


Submitted by Hoy on Thu, 05/27/2010 - 01:18

I have observed several times that green seeds can germinate instantly. Often when the seedpods are infested with fungus the seeds inside germinate in the pod! Even small, unripe seed can germinate. Maybe chemicals from the fungus trigger germination as a mean to survive the infection?


Submitted by Mark McD on Thu, 05/27/2010 - 05:17

Hoy wrote:

I have observed several times that green seeds can germinate instantly. Often when the seedpods are infested with fungus the seeds inside germinate in the pod! Even small, unripe seed can germinate. Maybe chemicals from the fungus trigger germination as a mean to survive the infection?

I also noticed that when the pods are left on the plant, and they start to yellow, invariably the pods get bored into by some sort of insect, the cavity usually emptied of any seeds that might have been in there.  Iris koreana at least made a lot of seed pods, and a lot of good seed inside, increasing the chance that some make it to dehiscence if they were left to mature on the plant. 

On Iris henryi, there were about 200 pods set initially, but only 4 pods swelled up into a good sized oval, like a small egg, to produce seed.  Maybe it got too hot and dry after flowering (hot weather here this spring), or we don't have the right pollinators for this species, but at least I was able to harvest and sow a little bit of seed.  It seems surprising, that these succulent "in the green" ephemeral seed, when planted immediately when ripe, actually don't germinate right away, but will be content to sit there the rest of the year and through winter, to germinate next spring... at least that is how Epimedium and Jeffersonia do it.

Trond, on what plants do you experience seeds germinating in the pod?


Submitted by RickR on Thu, 05/27/2010 - 07:04

McDonough wrote:

It seems surprising, that these succulent "in the green" ephemeral seed, when planted immediately when ripe, actually don't germinate right away, but will be content to sit there the rest of the year and through winter, to germinate next spring... at least that is how Epimedium and Jeffersonia do it.

Jeffersonia seed is hypogeal germinating.  They do send out a radicle that first season, so they don't just sit there.  Deno says they can send up a leaf in as little as 3 weeks from root initiation, or take several cycles of cold/warm to trigger leaf growth.

My Paeonia seeds are just sitting there. :(


Submitted by Hoy on Thu, 05/27/2010 - 10:57

McDonough wrote:

Trond, on what plants do you experience seeds germinating in the pod?

I have experienced this several times in the kitchengarden with beans and peas but also with wild Fabaceae and a few times with some Brassicaceae and once with a monocot. Can't remember the species. It is mostly  in the fall when the weather here can be very wet and plants start to rot when still growing.

Also ripe seeds can germinate when still on the plant, especially Asteraceae. All the seeds in a flower head can germinate in prolonged wet conditions.


Submitted by Lori S. on Thu, 05/27/2010 - 19:45

Wow, that's amazing, Trond!  (I thought I was doing well by getting a few Paeonia officinalis seedlings around the main plant every year, but I realize now it ain't even worth mentioning!  ;D)

RE. seeds germinating in the "pod", I cut open a butternut squash a while ago, and found the central cavity full of germinated seeds - very weird!


Submitted by Hoy on Fri, 05/28/2010 - 02:27

Skulski wrote:

Wow, that's amazing, Trond!  (I thought I was doing well by getting a few Paeonia officinalis seedlings around the main plant every year, but I realize now it ain't even worth mentioning!  ;D)

I forgot to mention, this is P. lutea var ludlowii and probably it's cross with P. delavayi.
The other peonies don't self sow like this!


Submitted by Mark McD on Mon, 06/14/2010 - 18:11

Having never harvested seed on Iris cristata, I've been wanting to do so, as an experiment to see if seed-grown plants show any variability.  I also needed to learn how to harvest the seed; when is the seed ready?  Every few days I've been picking a pod and snapping it in half to test the progress of the developing seed inside.  Today, I think the seed was ready as a few pods started to show a small degree of whitening in color, and a few other pods had actually dropped off (although remained unopened), surely ready to pick.

I harvested the seed on I. cristata 'Sam's Mini', a low growing variety found by Sam Norris of Kentucky.  On the photo showing the seed pods, those on the right show the lobster-claw like leaf bracts that each hold twin seed pods, the long styles are persistent.  Initially when testing seed for readiness, they were nearly clear or translucent... so I waited until they were a semi-translucent to nearly opaque tan or yellow color.  Harvesting the seed is as easy as snapping the pods in half, then gently squeeze the seed out.  They were sown fairly thick in flats, covered with fine decomposed pine back mulch, covered with wire mesh to prevent digging by chipmunks and squirrels, and they'll spend the year outside, hopefully to germinate next spring.

I have included photos to show what this plant looks like in flower, and when first emerging.  The rhizomes run on top of the soil, in fact, they prefer to slowly romp through the top layer of woodland duff or well decomposed bark mulch.  In this particular cultivar, the rhizomes amusingly look like they're leaping up and over like spawning salmon as they progress forward.