When do you introduce fresh air to your seedlings?

[EliWhitney3140]

I was curious what you personal preferences were to opening the sealed bags or containers of your seedlings? I have heard a few different time references, from 3 months to a year. Anyone have any info to share on the matter?

[keith]

1 year sounds like tiny slow growers . I quit growing in sealed plastic so IDK ? Back when I did I think it was months not years.

As far as treating them as adult plants, more sunlight, less water, transplanting, its a couple years or up to many years for Ariocarpus.

[EliWhitney3140]

Well I am mainly growing Copiapoa Cinerea, I am guessing that would be under the list of slow growers. Now that you mention it, how do you care for seedlings that aren't ready for adult care?

[Shane]

Now that you mention it, how do you care for seedlings that aren't ready for adult care?

If they're out of humidity already, less light/heat than adult cacti. At least that's what mine seem to want

[keith]

how do you care for seedlings that aren't ready for adult care?"

Less light and more frequent light watering not drenching like adult cactus. They have smaller roots that don't fill the pot.

Copiapoa Cinerea, I am guessing that would be under the list of slow growers' yes I agree

[7george]

I was curious what you personal preferences were to opening the sealed bags or containers of your seedlings? ===

Usually after some (~ 3) months after the germination, as soon as I think seedlings will survive and continue growing in an open atmosphere.


So seedlings have to be at least as large as the small ones on this photo. But it is better to focus on larger ones as most times smaller ones usually perish one by one at later times.

[Vingames1]

If you want your seedlings to get bigger faster leave them for 4-5 months. Most will be fine but if your seeing a lot of mold and fungus get them out of the bag

[LateBloomer]

It's been a few years since I've grown from seed but in a humid and warm environment like FL you can introduce to fresh air quite early on I've done so within a month of germination. Obviously growth will slowdown at first however just mist soil every few days to always keep damp (not wet). Don't let soil remain dry for longer then a day or so for the first few months... slowly reducing watering will harden the cactus seedlings into 'adults' quicker. Obviously this depends on the species you are growing but columnar cacti and many globular have no issue with this treatment. Obviously you will lose the weak seedlings however the seedlings will pick up growth quicker then those babied in baggies from my experience. You also introduce to more sunlight slowly... if seedlings are a little red thats fine growth will slow down once again but they will get use to the sunlight and grow much thicker after a few weeks.

This treatment is not 'optimal' however remember that cacti grow in very extreme conditions... in nature they have low germination and adulthood rate however we already provide them with optimal conditions a little stress from lower humidity and slightly higher sunlight will not kill them all.

Depends a lot on your climate. IF you live in a very hot and dry climate they will benefit from staying a little longer in the bags... In my climate my cacti never had a true dormancy however now I live in a climate that has temps as low as 3C so I will have dormancy during winter months. I will be treating all my 7-8 month old seedlings as adults and they will get very little to NO water for 3/4 months during the coldest months. I'll probably lose some seedlings however those that survive will then be crossed to have slightly more cold tolerant cacti after a few generations. I will be growing astro,ariocarpus and lopho which can handle these temps since it is not long periods and never 0C.

That all being said I have left aztekium seedlings in baggies for 6 months before opening the bags however they were all grafted afterwards so not sure on time from them.

I've seen many people leave in bags for upto a year you can probably get away with even 2 years or even indefinitely in baggies... I'll actually do an experiment with this once my growing season starts.
I'll do 2 bags and keep them inside for as long as possible reporting any issues such as rotting or mold. I'll sterilize soil-mix and use a fungicide to minimize issues; main issue will be winter months with lower temps and sunlight.

The root structure will likely suffer once bags opened and I'd suspect that unless you trim back most if not all the root they will die once a dry cycle starts.

[Download]

I open the containers once they start growing spines. Sometimes a bit longer if some seeds are refusing to sprout.

Plants need CO2 to grow, and cacti are really bad at absorbing CO2 from the air (the upside being they lose less water to the air). In a closed container they rapidly deplete CO2 and it takes time for the CO2 to diffuse into the container to replace uptaken CO2.

[PHcacti]

1 year sounds like tiny slow growers . I quit growing in sealed plastic so IDK ? Back when I did I think it was months not years.

As far as treating them as adult plants, more sunlight, less water, transplanting, its a couple years or up to many years for Ariocarpus.

Hi keith, can you share your technique/ process in growing seeds outside sealed plastic. Thank you!

[Shane]

Plants need CO2 to grow, and cacti are really bad at absorbing CO2 from the air (the upside being they lose less water to the air). In a closed container they rapidly deplete CO2 and it takes time for the CO2 to diffuse into the container to replace uptaken CO2.

This is an interesting theory. I'd never thought about that. For what it's worth, I don't think plastic bags are very airtight, at least not the cheap ones I use. It would be interesting to grow a batch of seeds in a bag and one in open air and see if indeed there's a difference in growth

[keith]

Hi keith, can you share your technique/ process in growing seeds outside sealed plastic. Thank you!"

I have pictures in this section in the Escobaria minima subject. Keep the top part of the tiny seedlings dry and the roots moist. I use screen covers with rubber bands on the pots. I expose to drier air as soon as possible. The air around here is not that dry though.

I still get fungus so my method is not fool proof.