I'll try to let you know in the spring how this all works out for percentages and the like.
I was inspired by the research article posted here a while back where they got significantly increased germination by soaking their seeds in straight bleach for two hours. So I decided I was going to try that.
Their bleach was 5%. I bought Clorox concentrated bleach at Costco which said about 8% available chlorine. So I mixed in a little less than half the bleach amount of water to reach an estimated 5% chlorine and got started soaking all my seeds.
I put them in a cup with a label and some of the solution. I got a little distracted, and didn't realize how long it would take to rinse the seeds, so the first batch were soaked for up to three hours. Gosh, were they white. Some of the smaller, greener seeds ended up almost translucent. Interestingly, the seeds that came from moldy hips and were black going into the treatment came out the whitest, almost translucent.
Despite a visceral attraction to the whiteness and purity of the bleached seeds, I started to suspect that in this case the solution might be more dangerous than the problem. However, I thought I should give this method a chance to succeed, so I added a little water to the bleach and reduced the soaking time for the next batches.
I then thought of another variable: I usually don't let my seeds dry out before sealing them in baggies. Maybe the relatively fresh seeds would be more absorbent to the bleach and it might reach the embryo and kill it. I got out my nail clippers and opened a few seeds and couldn't really tell, but when I tasted the embryo of a bleached seed I could taste the bleach. So I've likely killed 1/3 or more of my seeds for this year, but only time will tell.
Before I describe later experiments, let me tell you the rest of the procedure, the things that remained constant for all the seeds. For all methods I added a foliar adjuvant called Capsil to ensure good coverage of the seeds. I imagine this works like dish soap. Boy, could you see a difference. Many seeds will float just from the surface tension of the water. One tiny drop of Capsil allows them to submerge. Even seeds that still float are obviously suffused with water. I wasn't real careful about the amount of Capsil, but 1 mL seemed to be more than enough for a half-gallon of solution. It did seem like I had to add more Capsil the second day to a bleach solution, as if the bleach broke it down.
I decided I wasn't going to attempt to add too many variables, but wanted to try the calcium nitrate thing, so all seeds after the bleaching soak and rinse were soaked to varying lengths of time (1 hour to 7 hours, with the longer times being in a cooler) in a solution of one gently heaping small spoonful per half gallon of water. Also with Capsil. I didn't have a measuring teaspoon handy, so it was just a regular small spoonful, slightly heaped, and probably the solution was on the strong side. Then I dumped the seeds in a small strainer without rinsing. Pressing the strainer onto a towel sucked away the nested water at the bottom and allowed the seeds to be easily dumped into a snack baggie. I decided to use fresh baggies to avoid recontamination with mold, since many of my seeds end up getting moldy in the bag by this point. I did not use any vermiculite or sand, instead just putting the freshly moistened seeds into the baggie and sealing immediately. I would then seal a bunch of these snack sized baggies into a quart sized freezer Ziploc of higher quality so they don't dry out in storage.
Because of my bad percentages last year with a warm stratification period I have decided to take Don and Peter's advice and put the seeds immediately into the cold. I want to find as cold of a spot as possible to avoid early germinations, because I have too many crosses to be picking out germinating seeds and planting them one by one. I want to sow all of the seeds in March.
OK, so with 1/3 or half of my crossed seeds processed I decided to take a break and do some trials of bleach and Zerotol on OP seeds and those few crosses of which I had huge quantities of seeds. Zerotol is hydrogen dioxide, I believe, and works in the same manner as hydrogen peroxide. It should be noted that what is on the market now is Zerotol 2.0, which has an added ingredient, but I was using the original Zerotol.
The strongest dilution of Zerotol that is recommended on their website is 1:100. I figured if the foliage of a plant can handle that strength then I'd better use something like 1:20 as my primary dilution. Impressionable newbies should be advised that I might be an idiot.
The variables of my test were:
8% bleach diluted to half strength
Zerotol 100% (just a few samples for this)
Zerotol 1:1 dilution
Zerotol 1:19 dilution
Control Plain water
All solutions including had Capsil and I aimed for about 1 hour soaking time. All were then rinsed and treated with calcium nitrate. Fourteen seed parents divided into a total of 39 lots (not all parents were trialed for all four variables) for a total of about 5500 seeds. Most lots were 100 seeds, a few larger.
(Right at the end I relented and did one trial of calcium nitrate, just eyeballing an equal # of seeds, about 500 each of nitrate soak and a control plain water soak. Both presoaked with 1:19 Zerotol.)
For the rest of my controlled crosses I pretty much used a 1:19 Zerotol soak for one hour. In one case two crosses of the same seed parent were super black and moldy so I soaked one in 1:19 Zerotol and the other in 1:1 Zerotol. There was a color difference in the end result. I will post some pics.
I hope to find this thread in the spring and post results.