I think my hydrogen peroxide experiment may have been a failure. I sowed my pepper seeds a week ago, and have one total sprout, whereas I sowed two seeds per pod (36 pods total), sometimes three.
I know peppers take their time germinating, but I should have more than one after a week. So the H2O2 solution may have killed my seeds, and/or the length of the soak (24 hours in a 16:1 distilled water-peroxide solution).
I’ll give them another week to see how they do, but I’m probably going to have to try sowing another batch of seeds.
I think the recommended time to soak in diluted hydrogen peroxide is like 30 minutes. I wouldn’t soak seeds overnight in anything except water, personally.
Yeah it was probably too long, even tho I had seen several accounts of folks soaking them that long. I had another sprout yesterday but I’m not too optimistic about the rest. I thought a 16:1 solution wouldn’t hurt, maybe it was too long a soak regardless of the solution.
Plus my soil seems to be pretty damp even after a week, so maybe I need to try a different medium. It’s one of those bottom watering type of planters so it’s not going to dry out very fast.
For what it’s worth, did a literature search in the scientific journals on this. While there are quite a few studies looking at the effect of hydrogen peroxide soaks on germination rates, I could only find one on peppers specifically. Frustratingly, they forgot to mention how long they soaked.
So I looked at what was being reported for other seeds. The longest hydrogen peroxide soak I saw being recommended for any species was 8 hours. That was for corn, which of course has a much bigger seed than pepper. More typical was 30 minutes or an hour.
While this makes me think that 24h is far too long for peppers, it’s actually unclear, because of the dilution rate you used. The strength of the solution reported in the studies tended to be high, typically ranging from undiluted (which is technically already diluted to 3%) to 1% (for reference, diluting with 16 parts water would put you at 0.17%).
I used 3% peroxide, with a 16:1 dilution, so yeah it was pretty weak to begin with, but probably too long. My basis for length of soak was anecdotal, but I had read something about a study done at U Florida that soaked seeds for 12-48 hours in a stronger solution. It said 24 hours was ideal, anything longer didn’t make much difference.
So, looks like I’ll be resowing my peppers in a couple weeks along with my tomatoes. Probably won’t try the peroxide again, other than maybe a brief soak and rinse.
Might be looking into a different starter mix also.
I will soon be able to say if my manual scarification + much stronger (3%) solution + much shorter (10-20mins) soak was ruinous. While that may seem safely short, I suspect exposing the tender inner part of the seed to the hydrogen peroxide was a mistake. I couldn’t find a single study on any species where they combined the two techniques. We’ll see.
Yes keep us updated, I’m curious to see how it turns out. I think your method was probably less harsh than mine. I took have heard about the chamomile tea soak for softening the seed coat and help prevent damping off
One curious thing I noticed when I first put the seeds in the solution, was that I could see a bit of bubbling where the seeds were floating. I don’t know what that was, maybe it was cleaning off the seeds?
Or maybe it was the seeds giving up their last breaths…
I’ve decided to start my typical Sunrise sauce tomatoes and added Black Krim as well as Moonlight Miles, dads sunset and i need to add 1 red one now that I’ve listed everything out…
Super sweet 100 and i guess i need a grape tomato since this is all I’ve started. Realizing this as I’m writing it out.
Nadapenyo, purple/orange and red cayenne pepper. Maybe I’ll do Polano as planned. The posts above make me want to start a sugar rush peach too.
For bell peppers, i picked white diamond, Chinese giant, and etuida orange bell.
This year will be mostly focusing on the trees and berries so I’m not going all out with everything… i still need the area cleared and graded as well to be able to plant things without being in full shade.
Will make do a few varieties of mini melons again along with my favorite 2 cucumbers and cucamelons for my little one
Tomatoes - I love to grow San Marzano for sauce and Sungold Cherry tomatoes to pop in my mouth when in the garden. I’m still looking for a great slicing tomato. I’ve tried 4+ varieties and my yield is no where near as great as the paste and cherry type. I’ve grown Mortgage Lifters and though they are big, they aren’t very prolific for me. I’ve also done Rutgers in the past. I bought Brandywine seeds this year and hope they do well. I like to save seeds so I’ve been trying Heirlooms but I can’t give up my Sungold - so prolific and tasty.
Peppers - I love to grow Jalepeno, Banana Pepper, & Pobalano.
For scarifying seeds, I read one person’s method was to tape or glue a piece of sandpaper to the inside of a matchbox, or other small box, put your seeds in, then shake. Never tried it myself.
Interesting. Considering how firmly I needed to grip and press the seeds to make any noticeable impact, I’m honestly feeling a little skeptical about that working. But then again, perhaps I am misunderstanding something fundamental.
peppers are up potted now. I planted way too many hot Thai.
my over winter peppers aren’t waking up which is saddening, I had one I really liked that I kept over last winter and it did great last summer. but no leaves on it now. I’m hoping it’s just getting a later start. might put it on a bigger heat pad?
I had a few more pepper sprouts, about 10 so far, Aleppo, Orange Scotch Bonnet, Red Marconi, Stavros Pepperoncini and Cascabella. All but the last one of these are new seeds, the only newer seeds that haven’t come up are the Carolina Reapers, but they can take a while. My older seeds may just be bad.
But, I still think the peroxide treatment did more harm than good.
How has your experiment been doing?
I’ll probably be starting my tomatoes either this week or next, just going to sow them directly probably.
I’ve been germinating in cooler conditions and don’t want to reach any final conclusions yet because seeds are still actively sprouting. But so far it’s pretty clear the hydrogen peroxide did not devastate the scratched seeds because many of them have sprouted. Tho it’s all the newer pepper seed that’s sprouting, none of the old pepper seeds. BUT I’ve had an exceptionally high germination rate for equally old tomato seeds, so I am encouraged that some of what I did helped. Soon I’ll report out more precise germination rates!
Sounds like you’ve got a good lineup going for this year!
I sprout peppers and some tomatoes on a moist paper towel in a small Ziploc. I fold the paper towel so it is flat and stack the bags and place some where warm (on top a hot air vent under my desk). I don’t use heat mats for starting seeds anymore. This lets me know that the seeds are viable and speeds germination (mostly because of the heat) and no damping off (at this point).
