SunriseSide said:I just use ziplock bags with dry seeds for refrigerated storage. It works for me since I start pod harvest in June and don't start seeds until mid-October. At that point, I don't cold stratify here even dormant crosses from MI.
Hembrain said:It's my understanding that stashing dry seeds dry in the fridge is for storage, and that they can be kept viable for up to several years this way. Well-hydrated dry seeds sometimes germinate in the fridge during storage even before moisture is applied. ....However, if one wants them to really think they have had a winter and germinate strongly, applying moisture with chilling- moist stratification- does the trick. They sure don't all seem to need it, but it triggers rapid and uniform germination like gangbusters! I think it's worth the effort to enjoy the efficient results.
sooby said:To break seed dormancy the seeds need to have some internal moisture or they won't respond. If they don't have seed dormancy then they won't benefit from stratification. The same seed may possibly have seed dormancy at one point and not at another because seed dormancy can wear off in storage.
It's quite possible that people who dry refrigerate actually did not have seed dormancy, so the refrigeration was just storage. In studies even seeds from evergreen species benefited from moist stratification by germinating faster and more evenly. That latter is really the key, daylily seeds will germinate eventually regardless but some may take a long time, weeks or months if not damp chilled prior to starting You can't tell by looking at them or necessarily from their parentage.
It's quite possible that some people do not have daylily seeds that have seed dormancy. So you will get varying answers. In some cases the seeds are germinating despite what was done to them rather than because of.
Experiments were done in the 1950s as noted in the article on Rich Howard's website, as well as for that Daylily Journal article. In both cases a proportion of seeds germinated immediately without stratification so not all seeds in the batches had seed dormancy even though the parent (in the case of the DJ article) was a "dormant".and the seeds were selfed.
Storage and stratification are not the same thing. Refrigerator dry storage is to prolong the length of time the seeds remain viable, damp cold stratification is to break seed dormancy.
Seedfork said:I did a test one year with no stratification and with cold moist stratification. It was several years ago, and I don't recall
much about the results, but I did start using cold moist stratification after that. So I must have seen enough different that it impressed me enough to change, and nearly all my seeds are evergreens.
Edited to add:
I do remember that my seeds were sprouting over a long spread out period of time, and with the cold moist stratification they cut that spread out time down quite a bit. I wanted my seed to all sprout pretty much at the same time.
Perfect. Believe me, I read those studies over and over. Still not sure that totally applies to evergreens. Every study I've seen deals with dormants. All I crossed this year are solid evergreens. So doing some tests.
You mentioned studies with hydrogen peroxide, do you have a reference specifically for daylilies?
It's a fascinating topic and your experiments will be interesting - I assume you will make sure to leave some untreated seeds as a comparison.
bobjax said:(However, I strongly feel that Cold Stratification applies to seeds from Dormant type plants.)
sooby said:Is that 1% total H2O2 or 1:99 household 3% hydrogen peroxide to water?
Hydrogen peroxide does appear to break daylily seed dormancy. When I tested it at various concentrations the stronger the solution the faster the germination (I left them soaking in it until protrusion of the radicle). What I should have done was follow through to see if there were any longer term negative effects on growth from the stronger solutions. My controls were plain water, and planting normally. Plain water soak resulted in worse germination than just planting without any pre-treatment for daylily seeds with seed dormancy. But of the two or three seeds that actually did germinate in plain water, their initial growth was better than those in the peroxide.
Quite a few people do germinate their daylily seeds in dilute hydrogen peroxide but once in a while I've heard of some seeds that don't respond and need to be stratified.
As far as I know, no one has done the necessary test for daylilies. That would be to cross two cultivars in one environment where it would be advantageous for seeds to be dormant when they mature in the autumn. The same cross would need to be done in a different environment where it would not be advantageous for the seeds to be dormant when they mature in the autumn. Note, if the seeds mature at different times of the year/(growing season) that may be all that is required for the seeds to have more seed dormancy in one location than the other or for more of the seeds to be dormant in one location than the other.
Very interesting to read about your tests. Do you remember what strength you used? The dilute formula, like 1 tablespoon to a pint of water seems to me to be for disease control, although I've read 2 tablespoons for that.
To softened the skin to speed germination, I calculated it at 1 cup (for example) of 3% and two cups of water to get to a 1% solution. But I'm a little confused because somewhere I saw that it is 1 cup to three cups to get to 1%. The whole concept is about weakening the outer skin so water can get in. Griesbach actually found very good results by cutting the skin away. But I'm definitely not doing that.
Commercial hydrogen peroxide is at a higher strength than the drug store version. I used the household hydrogen peroxide which is 3%, further dilutions shown below.
In the tests I did the seeds were from a selfed deciduous species-type daylily. Are you implying that the 25% that germinated immediately without stratification would have been evergreen?
For foliage or growth characteristics to be related to seed dormancy characteristics they would either have to be the same gene or two very closely linked genes - therefore effectively acting as one.
Stout determined that "evergreen" was dominant to "dormant". We can label "dormant" daylilies as dd and "evergreen" daylilies can be either Dd or DD.
A "dormant" (dd) daylily can be crossed with DD, Dd or dd.
dd x DD produces only Dd or "evergreen".
dd x Dd produces 50% of each
dd x dd produces only dd
An "evergreen" (DD) daylily can be crossed with DD, Dd or dd.
This only produces "evergreen" either Dd or DD.
And lastly an "evergreen" (Dd) can be crossed with DD, Dd or dd.
Dd x DD produces only "evergreen"
Dd x Dd produces 25% DD 50% Dd and 25% dd
Dd x dd produces 50% Dd 50% dd
A proportion of "evergreen" x "evergreen" crosses would produce 25% seeds that were dormant.
"dormant" x "dormant" can only produce seeds that are dormant.
I suspect that some "dormant" x "dormant" crosses produce at least some seeds that are not dormant. That would not be possible if foliage/growth habit and seed dormancy are genetically the same..