I would introduce a quarter-strength, balanced fertilizer such as Dynagro 7-7-7 or Jack's 20-20-20 when you moisten your soil before or after you sow the seeds. Young cactus seedlings don't need a lot of fertilizer at this stage and you could probably wait a couple of months to apply the fertilizer ...

I will post results as they come in. I am interested in long-term disinfection, especially for the baggie technique of sowing. I'm looking for something that will allow me to leave seedlings in bags for up to a year. The best results I have gotten were from using both Chinosol and Physan 20. at sowi...

I am running some tests using Hydrogen Peroxide and Physan 20 on seeds when they are sown. So far, Mammillaria heyderi and Echinofossulocactus seeds sprayed with straight 3% peroxide right out of the bottle did not germinate after two weeks, while those that had only distilled water spray at sowing ...

I've never had a problem with just opening the bag and taking the pot out. There is no benefit that I can see to gradually opening the bag.

Thanks, Dave, I appreciate it. Lots of good articles in that one.

I water both my outdoors and greenhouse cacti every week or two in summer. I almost always do it early in the day when the air temps are 75-80°F. They say plants go dormant in the heat and many do, but a lot of mine continue to grow if they are watered and fed. I have a large batch of 0-1 yr old see...

I tried an experiment where I didn't heat-sterilize my soil before sowing some seeds and putting them into a ziploc. I relied on Physan 20 (2.5 ml / 32 oz boiled rain water) to treat seeds and soil. Two weeks later I have these little spheres of black mold/fungus?/whatever growing on the surface. An...

Those seem huge for 4 months old. Mine are still about the size of a pin head at 4 months.

Thanks for the replies. Capillary matting sou ds like a good idea, greenknight.

In your experience, do seedlings that are 1-2 months old have to be kept in moist soil all the time? I have had to take some of them out of their ziplocs because of excessive algae or mold. Since then (2-3 months ago) they have not shown much, if any growth, and I'm wondering if letting the soil go ...

I am very sensitive to airborne particles of any kind and dust from perlite, vermiculite, pumice and the like can cause a lot of trouble for me. I use one of the better masks from 3M and I can tell a big difference in what I inhale than using no mask at all. They don't keep 100% of the particles out...

I get hotter temperatures, up to 300F. I assume this would kill more pathogens than heating to boiling point only. It has not damaged the MW and I've been doing it for years. Nothing has caught fire either. Maybe there is enough moisture my soil mix to prevent damaging the MW.

Shane, I've had mostly good germination from their seeds. Some gymno seeds haven't done well, but I could say the same about the same species from other seed vendors. PDN ships seeds out pretty quickly, too. Most impressively, I got Strombocactus and Turbinicarpus seed from there that have germinate...

Thanks for your response, Frank.

G'morning Edwin, I also scater seeds on top of media. I think you saw my photos which were after repotted. I repot 25 seedlings in a 10 cm square pot always. Frank Good morning Frank Ah OK Still, it nice to see these neatly arranged seedling 👍👍👍 EDWIN This is slightly off-topic but Frank, when you ...