Cold Stratification

16 comments

Whilst it is too unpleasant to go outside, I thought I would blog about the cold.
Some plants need a period of cold in order to germinate. Iris are such plants. In the past I have put Bearded Iris seeds into pots and left them somewhere cool over winter so they germinate naturally in the Spring. I have also tried putting the Pots of seeds into the fridge to hasten germination. Some will germinate the same year, using this method, not waiting for the following spring.
This year after a regime of soaking, bleaching and putting in the fridge bought seed of Iris pseudocorus Alba, (as per the germination instructions), I got almost 100% success.
I decided to try this method with seed of my Beaded Iris crosses. After the soaking process, 1 hour for 5 days, then a 10% bleach solution to kill of any fungus etc, I would put into the fridge for the required 90 days.
Problem , Too many seeds, too many pots, taking up too much room and not all the seeds germinate at the same rate, so I put the seeds between wet kitchen towel on ice cream tub lids, stacked them up, putting the pile into a poly bag into the fridge.

After about 40 days I started checking weekly. In the second photo you can just see a seedling starting to produce a root. When they got bigger I put into these small home made pots, with a view to potting on when big enough. These pots turned out not to be a good idea as the tiny roots grew out of the holes I had made in the bottom and when I tried to turn out, the roots broke off. So I potted any seedlings straight into pots to continue growing in the conservatory.

After 90 days I also potted all the ungerminated seed and put these outside as some could still germinate now, next Spring or even the year after.
There has been a big problem with leaving the seed between wet kitchen roll, all the names pencilled on the labels have become erased! This is a problem I am in the process of trying to solve. I do have a paper copy of the crosses I made, but I have had to relabel the pots A, B, C, etc.
The other problem….where to put this years seedlings (ex 2016 seed)as they get bigger.

My terracotta tubs (I painted them with black bitumastic paint as they were crumbling) all 12 of them are full of 2015 seedlings, lined up under the car port edge.

Some of the bigger 2015 seedling were put into the garden, during late summer, leaving these still in the tubs. Look how they have grown, not having been subjected to the elements and slugs and snails, better now than the outdoor ones, even the 2014 seedling.

New year 2015 I made a resolution, which I prompt broke, not to buy any more Iris Rhizomes. This year definitely no more purchases, as I so need suitable sunny places to put any mature enough to flower and are worth keeping.

I leave you with a pic of a precocious plant that flowered last year from 2014 seed, the only seedling to do so. I have several more plants of this same cross, Bronco Down X BB Maid of Orange. Will they be similar? A Martha’s Gold lookalike.

Can’t wait till Spring to see if some more of the 2014 and even 2015 seedlings flower.
S’iris

28 Jan, 2017
11 likes

Comments

Terratoonie

Wow... useful blog, Siris ... I have only limited GoYpedia headings to choose from, so have added to Storage Ideas and Plant Labels.

28 Jan, 2017

Siris

Propagation? Terra.

28 Jan, 2017

Terratoonie

Hi Siris ... I wrote to GoY management about 2 years ago, with repeated reminders, that I am willing to take on lots of the GoYpedia categories which have been defunct for several years because the members editing those pages no longer visit GoY, but I have had no success in being given extra categories. Also, creating new categories used to be something Peter did promptly, but sadly not any more.

I've just nominated this blog for Irises, but IRIS is one of David's pages and he hasn't contributed to GoY for years, so unfortunately, the nomination won't be seen or acted upon.

Sorry... I would love to help more, but cannot ..

28 Jan, 2017

Siris

Thank you Terra, I was not expecting or bothered about it being nominated for GoYpedia. I have come across some most interesting tips/thoughts just by reading others' comments in photos or blogs and have personally put them into my favourites for my information, least I should forget.

28 Jan, 2017

Terratoonie

Yes.. the Favourites facility is a useful idea.

28 Jan, 2017

Bathgate

I've debated over the need for cold stratification and pleased to finally get affirmation. Do seeds not always come true to the parent plant or is it like pot luck?

28 Jan, 2017

Cottagekaren

Wow! Some of the lengths gardeners go to in propagation are wonderful. I prefer to leave this mostly to the pros. I support them by buying from them. This is how I justify my laziness and excessive garden spending! I'm absolutely convinced that the success of the D..b..s chain is mostly down to me...and that my favourite independant nursery owes its living to me as well! Lol....positive spin...thats my mantra! Well done Siris...will you be opening a nursery soon too? ;)

28 Jan, 2017

Siris

Oh Bathgate, Vegetative propagation eg offshoot rhizomes will be identical but seed not necessarily so. The appearance of the resulting seedlings depend on the dominance of the genes from the parents for any particular trait. You, in the USA, have some excellent articles written about genetics. Your National Gardening Association has an Iris Database which lists parentage, which is most helpful, just google Bearded Iris (name eg Maid of Orange) and look at their entry.

Karen, You lazy! No way, you are always working to make your garden a place of beauty, just different ways of expressing the desire to create something? A nursery for my own pleasure, I wish!
As a Goy member quoted ...TO PLANT TODAY IS TO BELIEVE IN TOMORROW.

28 Jan, 2017

Linda235

Wow! You deserve a medal for patience. They look so good tho'.

28 Jan, 2017

Paulspatch

Very interesting blog. You have such patience.

28 Jan, 2017

Dottydaisy2

Sue you are to be commended on your dedication and passion regarding Iris, but I am with Karen on this one .....we keep most of the local Gcs going and several online stores as well!! I admire your patience, you obviously enjoy the challenge, it is good thing there are people like you!! well done!

28 Jan, 2017

Sandra

Very interesting Siris. I have done this with tree seeds I the past. I never tire of the excitement of spying the first green shoot to pop up out of a seed tray! Good luck with your new plants.

29 Jan, 2017

Siris

Sandra, I couldn't agree more about the thrill of growing something new from seed. Also with crosses the excitement of seeing wether you have created some novel new variety, although the chances of that are a million to one against unless you are a big 'player'.

29 Jan, 2017

Sandra

I'm a little player...lol but collecting seeds especially when there's a chance of .....a new one.....is soo exciting. Aeonium seeds are my favourite ... I have some Giant red wood seeds I collected while on a visit to my dad in as well as echium seeds from my garden. Onion seedling are growing fast...Trying to wait before the tomatoes go in.

30 Jan, 2017

Siris

How exciting, Sandra, but you have lots of space to indulge your nurturing needs. Time for you to see the Giant Red woods mature, more than problematical. Lol

30 Jan, 2017

Sandra

After living here for 25 years space is running out. It won't be my problem when the garden has turned into a forest..lol

30 Jan, 2017

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