Question about replating and hydrogen peroxide

[Silje]

I'm seeding orchids without a glove box this way:
Seed sowing - the lazy way


And I'm doing my best sow few seeds in each flask to avoid replating, but I've had some accidents now and then and I have some flasks that really should be replated.

Now...
Can anybody tell me how tiny seedlings respond to hydrogen peroxide? Will they survive being sterilized with H2O2 again, or do I need to make another plan?

If H2O2, how strong should the solution be? And how have you done it?

If not, H2O2, are anybody here replating without a glove box? How does it work? What's your tricks and secrets? How do you sterilize the flask?

[Orchid Whisperer]

Hi Silje

I have used this non-glove box method, which relies on chlorine bleach:
Very Easy Sterilisation Method - My Seedlings

I have not replated, but instead have had modest success moving very small protocorms onto fine chopped sphagnum which was boiled and cooled first. The tiny plants develop very slowly, but I am not trying to produce huge numbers of plants quickly.

[Subrosa]

I cannot speak to orchids, but I recently germinated some seeds of a mesemb known for damping off if you think about looking at them wrong. I watered with household H2O2 at full strength (3%) and had no issues with fungi or seedling damage.

[Fairorchids]

Keep an eye on the replates. If you get an isolated infection (mold or whatever), you can burn it away with a magnifying glass and sunlight, by focusing the rays on the infected spot.

This works with glass flasks. I have not tried with plastic flasks. You might want to test with an empty flask first.

[Silje]

Originally Posted by Orchid Whisperer

Hi Silje

I have used this non-glove box method, which relies on chlorine bleach:
Very Easy Sterilisation Method - My Seedlings

I have not replated, but instead have had modest success moving very small protocorms onto fine chopped sphagnum which was boiled and cooled first. The tiny plants develop very slowly, but I am not trying to produce huge numbers of plants quickly.

I've found my germination method. 'The lazy way' works perfect for me and requires so little, I'm going to stick with it. This is more for the replating.

What I was considering was to just pick out some of the protocorms/seedlings in the the densest flasks and then just sterilize the flask with H2O2 again. Which would be super easy. I'm lazy as you can tell.

But I have no idea if seedlings can handle H2O2.

---------- Post added at 06:47 PM ---------- Previous post was at 06:43 PM ----------

Originally Posted by Subrosa

I cannot speak to orchids, but I recently germinated some seeds of a mesemb known for damping off if you think about looking at them wrong. I watered with household H2O2 at full strength (3%) and had no issues with fungi or seedling damage.

Cool! That sounds promising. I've normally used 5% H2O2 for sowing, but I can weaken it a bit.

Thank you!