Pacific Coast Iris Germination Technique

Submitted by Tingley on

When my seed selections arrived from the Society for Pacific Coast Native Iris, I decided to follow a recently recommended method to improve my germination rate. Kathleen Sayce ran an experiment documented in volume 40, Spring 2012 edition of the SPCNI Almanac. I used a nail file or simply my fingernail, to scratch away as much of the seed coat as possible, on every seed. The seeds were placed in leakproof ziplock bags, partially filled with water, and sealed.

The bags were left at room temperature, out of direct sun (but not in darkness). The water was replaced once or twice during the month long soak- some batches of seed caused the water to discolour  at first, as plant extracts leached out of any remaining seed coat.

Over the past two weeks, seeds have begun to germinate. As soon as a bag shows signs of germination, the contents are transferred to seed flats for growing on. Germination rates have greatly improved since I began using this method, sometimes verging on nearly 100% germination, when my first attempts barely reached 40% success.

Germinated Pacific Iris seeds 72.17 KB

Comments

Submitted by Fermi on Sun, 03/09/2014 - 06:27

Hi Gordon,

did you try this with any other type of iris or just PCIs?

What temperatures did the seed experience?

I've had variable germination on some iris which aren't considered difficult and I wonder if this method could be used with them,

cheers

fermi

Submitted by Tingley on Sun, 03/09/2014 - 07:13

Hi Fermi,

I use this technique for Pacific Coast Iris, and it seems to work very well. my germination rate is up to respectable levels (in some cases up to 90%), and seedlings appear more quickly (the barely sprouted seed that was potted on Feb 21st is now up, and well on the way). The seeds in their water bath experience daytime temperature of 20C (68F), and overnight temperature drop to 15C (60F). They are not in direct light, but certainly not in darkness either. The bags were placed together in a bowl in a shady spot below a window on the north side of our house (it would be your south side).

I use a different method for Iris ensata, and members of the Sino Siberian group. These seeds seem to have a corky layer (probably for floatation). I fold these up in damp paper towel, and they go into ziplock bags and into the refrigerator for several weeks (haven't germinated ensata for a while,  so can't remember how long the refrigeration period was.). I now have bulleyana, chrysographes, delavayi, forrestii, and wilsonii in the fridge- they went in on March 7th. I'll look at them in about three weeks to see how they are doing.

The more I get to know these iris, the more I have come to believe that germination inhibitors are to be found mainly in their seed coats. I scratched away what I hesitantly call the corky exocarp of some of the Iris ensata seeds, after their stay in the fridge, and planted them separately from those that were intact. The cleaned seeds were up well before the 'Natural' ones appeared.

Which species are causing you challenges?

Submitted by Toole on Sat, 03/15/2014 - 01:55

As you might remember Gordon  I also obtained PC Iris from the same source as you .These were sown outside upon arrival a few weeks ago and kept moist .Interestingly all pots now are currently sowing germination under the surface although I have no idea of the percentage in each pot.

Cheers Dave.

Submitted by Toole on Sat, 03/15/2014 - 01:55

As you might remember Gordon  I also obtained PC Iris from the same source as you .These were sown outside upon arrival a few weeks ago and kept moist .Interestingly all pots now are currently sowing germination under the surface although I have no idea of the percentage in each pot.

Cheers Dave.

Submitted by Toole on Sat, 03/15/2014 - 01:55

As you might remember Gordon I also obtained PC Iris from the same source as you .These were sown outside upon arrival a few weeks ago in the state they were received and kept moist .Interestingly all pots now are currently sowing germination under the surface although I have no idea of the percentage in each pot.

I would have replied earlier however am still coming to grips with a new computer and the move from XP to Windows 8.1 ......laugh

Cheers Dave.

Still haven't sown my PC Iris I received, been working ridiculous hours and special projects, getting burnt out quick, now looking yet again for a new job with some level of normalcy.  Maybe I can sow them very soon, we're still in the deep freeze here, but spring eventually has to arrive.

Good luck with Windows 8, many business enterprises are sticking with Windows 7 because not all software is certified on Windows 8.  Personally I really dislike the child-like "colorful rectangle" look of Windows 8, why is there a driven need to reinvent the wheel with each Operating System update?

[quote=Mark McD]

Still haven't sown my PC Iris I received, been working ridiculous hours and special projects, getting burnt out quick, now looking yet again for a new job with some level of normalcy.  Maybe I can sow them very soon, we're still in the deep freeze here, but spring eventually has to arrive.

Good luck with Windows 8, many business enterprises are sticking with Windows 7 because not all software is certified on Windows 8.  Personally I really dislike the child-like "colorful rectangle" look of Windows 8, why is there a driven need to reinvent the wheel with each Operating System update?

[/quote]

Running XP was like owning a Mini ,Mark --upgrading to Windows 8.1 was like trading it in for a Merc ......laughalthough no doubt helped by the fact I brought a faster machine.