First time growing cactus from seeds

[Yannicknc]

Hi everyone,

I just started growing cacti from seed for the first time. The seeds I got from Valley Succulents here in Canada. I planted 10 varieties 11 days ago and so far have at least a few seeds have sprouted of each type. I thought I would post some pictures of my progress and see if anyone has suggestions for improvements.

The set up I am using is 2 LED 24w lights with a heating pad setup to a thermostat set to 25 degrees Celsius. Both the lights and the heating mat are set to run 15 hours a day.

I am using the "baggie" method and sterilized the growing medium in the oven before planting. However as you can see from the photos I am having some algae growth. I think when the seedlings get a bit bigger I may put some small sized gravel as a top layer to help support the seedlings and hopefully combat the algae.

My soil composition was close to equal parts sand, soil, and perlite with a small amount of 2mm-4mm gravel. I feel I may have gone a bit heavy on the sand. I also didn't flatten the top of the growing medium in the pots properly, which caused a number cracks or crevasses in the soil. A good lesson for next time.

Thanks

Yannick

[Aiko]

You can more easily fight the algae by allowing the soil to dry out every now and then. It is a bit of a balance between drying things out but also allowing the very small seedlings to not get dried out for too lang. The older they get, the better they can cope with dryness. This will help better than adding a layer of grit on the top.

Keeping the bags closed will prevent some more algae. I guess you opened the bag a few times?

I think you have a pretty good germination rate going here.

[Yannicknc]

You can more easily fight the algae by allowing the soil to dry out every now and then. It is a bit of a balance between drying things out but also allowing the very small seedlings to not get dried out for too long. The older they get, the better they can cope with dryness. This will help better than adding a layer of grit on the top.

Keeping the bags closed will prevent some more algae. I guess you opened the bag a few times?

I think you have a pretty good germination rate going here.

Thanks for the advise. I actually hadn't opened the bags until I took the photos. But I think I may have over watered them when I sowed them.

[Edwindwianto]

What is this interesting red seedling on the upper left area
Wow

[greenknight]

The algae isn't really a problem, it won't hurt the seedlings. Enough moisture for cactus seedlings is enough for algae to grow - it doesn't mean you over-watered, just that algae spores got in (which is hard to avoid). I don't worry about it, once the seedlings are old enough that drying out a little won't endanger them you can let the surface dry between waterings and get rid of it.

[Yannicknc]

What is this interesting red seedling on the upper left area
Wow

That seed came from the Astrophytum v. strongyiogonum bag so I assume it is one of them. But I guess it could also be a stray that got mixed in the bag.

[Yannicknc]

The algae isn't really a problem, it won't hurt the seedlings. Enough moisture for cactus seedlings is enough for algae to grow - it doesn't mean you over-watered, just that algae spores got in (which is hard to avoid). I don't worry about it, once the seedlings are old enough that drying out a little won't endanger them you can let the surface dry between waterings and get rid of it.

Thanks for the info, it is reassuring to hear that the algae isn't to much of a problem.

[Edwindwianto]

That seed came from the Astrophytum v. strongyiogonum bag so I assume it is one of them. But I guess it could also be a stray that got mixed in the bag.

Good
At what point do we need to graft this seedling in order to keep it alive? As in, what age?

[Hanazono]

I do not know what grafting method you try to do but 40 days after germination is the best timing of myriostigma seedling grafting.
Stocks should be pereskiopsis, hylocereus or jusbertii.

The red one may not be a variegated seedling.
A variegated myriostigma in this age is normally pale pink.
Since I only can see the photo, my comment may not be accurate but there is a Japanese cultivar showing a similar colour during seedling age.
The cultivar has been in Thailand.

[Yannicknc]

I had not intended to try graft any of these seedlings. Do you think that would be beneficial? Personally I usually prefer cacti that are grown naturally rather than grafted.