The "cup of tea" method for germinating seeds

[Matt T]

Hi Robert,
Yes, I've found that the Scilla with larger seeds (i.e. S.siberica, S.peruviana etc.) do great when sown at depth. Those with slightly smaller seeds like S. verna would not be quite so deep.

[Lesley Cox]

I wonder how many of the Iris experts use such a rinsing technique? It sounds a lot like the tea procedure.

Yes, I remember reading about this. too. I think it was applied to Daphne seed in particular and perhaps to Trillium seed, in the former case, to wash away possible germination inhibitors. I haven't tried the loo tank but there it is, and surely could be put to good use, well a second good use.

[Matt T]

...wash away possible germination inhibitors.

Having been reading around this subject, including Deno, I'm inclined to think that the washing is likely to be more important than gibberellins. However, it might be that tea is a better washing agent than plain water, i.e. the mild acidity of tea could help remove any inhibitors? Potential for so many experiments here...but too little space for more pots 

UPDATE: there are not yet any signs of germination in my experimental pots one week after sowing.

[Lesley Cox]

Re your update Matt, I think the sowing time may be a factor too as my soaked iris seeds were sown in winter and only a couple have germinated so far while Laurol's big batch that got me so excited were sown in the autumn. My more recent spring sowings are starting to germinate - well it's JUST spring here yet - while the winter lot are still sitting. Herbaceous things that weren't soaked are starting too, along with 4 pots of Corydalis solida sown within a couple of days of harvest, but starting 15/16 months after sowing. Iris cycloglossa sown last November is coming up like hairs on a dog's back. A hairy dog at that. It was seed given by Tony Hall to South Canterbury Iris group for the Convention last year and a couple who didn't want theirs (I had received a North Russian I. sibirica in my "goodie" bag) gave it to me. There was enough for 3, 100mm pots! The I sibirica started in May. There's always something interesting and exciting happening among one's seeds, no matter what the time of year.

[vanozzi]

On 11 Aug this year, I also have sown some Siberian iris seed using the tea method.The seed is one and two years old, was soaked for 4 days in tea and changed each day.No germination yet.I wrapped the seed using chux cloth, attached a label and not knowing if tea would erase the ID , I wrote it twice, using different pens haha.It was fine.
I should have some really choice fresh siberian hybrid seed arriving from the US shortly and will use the tea method on half, the other half just soak in rain water for the 4 days.
 
My Japanese iris seed was sown prior to reading Lesley's post, so I have just watered them a few times with tea.

[Tim Ingram]

The great thing about doing science is that you don't know the result until you have done it once, repeated it another few times, and then someone else has done the same and found the same result. And then you have some degree of confidence you are on to something! The problem here is possible confusion between several different potential explanations: hot 'tea' (water) simply softening a hard seed coat and allowing the seed to imbibe when it normally would take a long time for the seed coat to degrade and allow imbibition; washing out of inhibitors like Matt says; and actually a direct effect of a hormone like gibberellin. It would be possible to test with actual gibberellin as another experiment.

Practically if germination of tricky seed is stimulated it is quite a beneficial (and cheap) method regardless of the underlying reason(s) - it's great that several people are trying this out but since most scientific experiments don't give especially clear cut results I imagine there is likely to be quite a bit of variation. Will be really interesting to see what happens over the next weeks and months.

[Matt T]

UPDATE
Ten weeks into the experiment and there are not yet any signs of germination in any of the pots I have sown. I suspect that the cup of tea method may not be of benefit to species that have a requirement for a cold period to germinate (in this case Muscari, Scilla and Narcissus). I'm planning to add some recalcitrant species to my seed exchange order this year and will include any that I receive to this trial in the spring. Watch this space...

[Robert Pavlis]

Preliminary Update:

Paeonia officinalis ssp banatica, Paeonia cambessedesii and Iris colletii are showing no germination with either water wash or tea wash.

Paeonia veitchii v. woodwardii showing 30% germination with water wash, and 0% (1 out of 10 seeds) with tea wash. Paeonia veitchii v. woodwardii that were not washed at all are far ahead of either washed set of seeds, and many seeds have long roots already.

Paeonia anomala showing 60% germination with water wash, and 10% (1 out of 10 seeds) with tea wash. The unwashed set of seeds is far ahead of the washed seeds as far as root growth goes.

Washing a seed that had a root showing seemed to halt the germination process and the root stopped growing. It might even have damaged the root tip to a point where it stopped growing.

So far I'd make 2 conclusions:

1) washing with tea is not better than washing with water
2) for peony seeds, washing (with water or tea) does not seem to add any advantage over not washing.

I have not counted the # of seeds that germinated in the unwashed package of seeds--it does contain many more than 10--maybe 50. The roots are quite tangled up right now and I don't want to disturb them. It is therefore possible that washing does increase the % of germination.

[Matt T]

WEEK 19

Some seeds are showing! Only the Narcissus pseudonarcissus seeds are germinating:

3A - soaked 4 x 24 hours in green tea
3B - soaked 4 x 24 hours in black tea
3C - soaked 4 x 24 hours in water
3D - soaked 24 hours only in water

There are 2 seedlings showing above the top dressing in each pot (no poking around with exploratory fingers), with treatment 3C having one seedling that was also showing last week.

No other signs of germination to date, including pot 3E, the Narcissus seeds that were sown dry without being subject to any soaking treatment.

[Matt T]

WEEK 20

3A - 2 seedlings
3B - 2 seedlings
3C - 2 seedlings
3D - 3 seedlings (+ 1 since last week)
3E - 1 seedling (new since last week)

[Matt T]

Week 23

A lot of Narcissus seedlings are coming up. For Narcissus pseudonarcissus at least and to date, it appears that there is no significant difference in germination across all treatments.  The use of species with a cold-requirement for germination was identified as a potential limitation of the experiment.

[Matt T]

Week 25

[annew]

YAY! The no-soakers caught up!

[Matt T]

Week 30

Germination on the Narcissus seeds has plateaued, with few new seedlings pushing up now.



Muscari and Scilla have also started to germinate, here's the chart for M. armenaicum to date (no-soakers leading the way, Anne!)

[Tim Ingram]

No obvious differences in the use of 'tea' in these examples. We should return to Lesley's original post which referred specifically to recalcitrant seed (i.e. some irises) and look more closely at these, because here there is good evidence of an effect.