Can you clarify why you consider seeds need sterilizing? Are these self collected seeds? Do you suspect they are contaminated in some way? Are you growing large numbers or commercially? Are you conducting experiments that require sterile conditions?

floral_uk :-

Seeds that could do with cleaning include self collected. Commercial seed are considered to be already treated.

Everything everywhere can be said to be contaminated.

I am just a home gardener..

I'm not experimenting, just wanting to get the best I can from, in this instance, old rare seed.

From " How Does Hydrogen Peroxide Affect Seed Germination? | Hunker " and like sources " hydrogen peroxide solution was most effective at breaking seed dormancy and inducing germination "

Art

ken-adrian

Old seed of an endangered HA.

In your sowing regime you could then introduce damping off etc with the seed

Regards

Art

HA???

yes.. its possible that the seed itself could start the problem... but the media .. volume wise.. is 99.99999999% of the possibility....

after i started sterilizing media.. i never had damping off again .. nor excess algae .. or green stuff .. no random weeds.. and no bug or gnat issues .... i used variations of promix... fyi .... and always used new.. with seed.. no recycling of old media at this phase of the process ...

all that said.. i can understand your concerns with heirloom rare seeds .. i presume you dont have a plethora of excess seed to take the usual losses associated with germination.. and want to do your best to perfect the system ...

good luck

ken

ps: its tough to work plethora into garden posts.. lol ...

What method do you use to sterilise your compost, its not easy to do a decent batch size

Art

PS. Btw, the seeds I am trying to germinate can take 280 - 700 days to start to grow. While researchers have found that they can be found in the wild flowering after absences of 3-4 years. They can be found in profusion with nothing to hinder them, and yet be absent for another 2-3 years before a new flush

I’ve never found it necessary to sterilize seed whether bought or collected. In nature seed is not sterile. What seeds are you growing and what is the contamination you fear?

Hello Art,

" Btw, the seeds I am trying to germinate can take 280 - 700 days to start to grow. "

Well, that's not typical. I would be tempted to mechanically breach the seed coat of those, to speed things up.

I assume the zinnia seeds that I save are pre-infected with some zinnia disease and I apply something like Hydrogen Peroxide or Physan 20 to sterilize them. I have an old microwave oven in the utility room where I start my indoor seedlings, and I sometimes microwave some pre-dampened medium (I use ProMix) to sterilize it. That is practical only for small amounts of the medium, enough maybe to fill half a dozen 3-inch pots.

ZM

zen_man, the seeds take on water well enough, they swell in an overnight hot water soak. But that can maybe help with some dormancies.

I also use a microwave to sterilize

Regards

Art

floral_uk :- the seed is from " galeopsis angustifolia "

The feared contamination is any contamination..

Regards

Art

I ran into this a few minutes ago. Some grower recomends to autoclave the water seeds are watered with !

I never clean tomato seeds let alone disinfect them. They get smeared on a paper towel so that when they dry they stick to the paper towel. Sloppy seeds like pumpkin, squash and cukes get rinsed till they're have just enough gunk that they also stick to another paper towel.

I've read that tomato seeds won't carry blights and septora, but I wouldn't argue that point.

However; if I were trying to start seeds that take 700 days to germinate I might be a little more cautious.