Advice for my first seedlings

[Sun_Love]

I'm back with some worries again.. they have grown a lot darker gradually lately. Is there something wrong with them?
The lid is on but I have kept the airvent on top fully open. Still putting a protective piece of paper on the window in the most intense hours of sun during the day. It's been exceptionally hot lately, our houses are not really built for heat and there is no AC, so almost +31 celcius indoors now. Could that have made them darken?
(the Rebutias in the other pot are still more light green like before)

[greenknight]

No problem, olive green is a normal color for this species - they're growing up! Looking good, I think the light level is perfect - and they appreciate the warmth.

Rebutia krainziana should also turn dark green in time, but they didn't appear to be as far along as these guys.

[Sun_Love]

Thank you, so happy to hear that they are doing good Sometimes I wish there was a pic guide for dummies "this is how they should look" etc haha
That's good to know that the others will also turn darker in time, right now they are light green but with spines about halfway down their bodies.
I spray a little water every other day, some days on top, some days under the pots.

[Sun_Love]

They just keep getting darker and darker, is it still normal? The soil is disappearing, that always seems to happen in my pots. Do I leave it as is, add more soil or replant?
The weather has turned unfortunately, cloudy darker days so they are not getting so much sun anymore..
(I had just sprayed water before I took that pic)

[greenknight]

They look good. They're growing well, and that's what's important. The slight hint of red means the light is on the strong side, which is good - they'll make nice stout growth, not become unnaturally elongated. Light that was too strong would cause them to turn very red or purple from stress, that could cause growth to slow - but you don't have that problem.

The Gymnos are far enough along now that they should be able to take transplanting without much risk. The soil has sunk very badly, and you can't add more on top of them, so I would recommend transplanting them. They're too small for individual pots, I would spread them out in 2 pots the size of the one they're in now. The Rebutias I wouldn't transplant, but you could add some soil to level out the pot.

Next time, press the soil down a bit before planting, then you won't get so much settling. Same thing when you're transplanting, gently firm the soil down around the plants to eliminate air pockets.

[Sun_Love]

Thank you
Happy to hear that they are growing as they should! I will repot the Gymnos and press down the soil (never knew that!)
2 questions..
Soil... for my other cacti I now have a mix of about 2/3 pumice, 1/3 organic cacti mix (commercial Focus mix). Do I do the same with the seedlings or more organic?
Watering... How much and how often? I normally water around once a week for the bigger ones ( then let dry out), because I've come to understand that I have in the past been underwatering my plants. Can I do the same with the seedlings or still keep spraying every other day?

[greenknight]

I would stay with the same mix they're in now. When you change to a different mix, you need to remove all of the old mix from the roots, and I wouldn't do that with cacti this young. You should try to transplant them with as little root disturbance as possible.

You could continue your current watering regime through the summer, or you could cut back to perhaps twice a week if it's more convenient. It won't hurt them now if they dry out for a bit, but keeping them constantly moist will maximize growth.

How are you going to treat them over the Winter? If you're going to rely on natural light, they'll need to go dormant over the Winter - if you can keep them growing at the current rate they should be big enough by then to take that.

[Sun_Love]

Thank you! I think I'll stick to spraying then, I want them to grow as much as possible

Winter... well I've never really done this proper dormant thing (because I didn't know about it) I just watered seldom and they were in a gloomy window. This was of course my bigger ones.
This year I want to do it right. I live in an apt with central heating, so it never goes below +20 C in that room (rest of apt is even warmer) Late Oct, Nov, Dec are really dark, no sun, grey skies , short days etc so I will get artificial light.
The seedlings I could keep on my work desk under the lamp ( in a warmer room) if that's better for them? I usually travel longer periods in the winter, but because of Covid I guess I will be here this year.

[greenknight]

You can keep seedlings growing through their first Winter with artificial light and they'll be fine. 20c is plenty warm enough - I doubt your desk lamp is bright enough to keep them from getting etiolated. If you're going to get a light for your other cacti anyway, you could keep them all together.

I recommend an LED light, they use little power and don't radiate heat. "Warm white" LEDs (around 3000K color temperature) work great. You don't need a special "grow light", they're not superior, as demonstrated in this video: https://www.youtube.com/watch?v=HawgP5SXPko

For your older cacti, it's best to give them a Winter rest even if you can't provide cool temperatures. Just do what you've been doing - water seldom. They will still benefit from the light even if dormant, it will help them retain their pigmentation and be ready to go in the Spring.

Many species will flower poorly or not at all without a cool Winter rest at around 5-10c, but they can still grow and be healthy, attractive plants. there are also tropical species that don't like cold, you could try some of those if you want flowers.

[Sun_Love]

First, thank you Greenknight for all the advice! I've been crazy busy lately and not on here for a while. I will figure out a good lighting solution before fall comes down heavy here. Right now we are back to heatwave.
As I've been busy it took me a few extra weeks to do the transplant, now they have been in the new pots for around 1,5 weeks.
Do they look ok? I think some of them look weaker/not so good?
The soil in the Rebutia pot had sunk a lot as well so I put them in the same pot as you can see. That's maybe weird, but I have a little lack of space for pots.
Some of the Gymnos rootballs stuck together so I let them, as I didn't wanna the disturb the roots. I was impressed by the root balls!

As for flowers, I would love to have them! I almost bought a flowering one this summer but it felt like cheating. I read you can put them in the fridge a few nights before spring. Does that work?

Anyways here are the seedlings..

[greenknight]

They look pretty good. There will always be variation, some will be stronger and others weaker. I see only one that I'd be concerned about - one of the Gymnos in the Rebutia pot looks quite red, which is a sign of stress. It may be fine, though, just have to wait and see.

Since they're all growing in the same conditions, I don't see any problem with mixing the two species in one pot.

I have no idea if a few nights in the refrigerator would make any difference. One forum member tried keeping cacti in the fridge for their entire dormant period with good results: https://www.cactiguide.com/forum/viewto ... f=2&t=4387

[Sun_Love]

Yes, that little one doesn't look so good. I hope that they all make it, but I'm prepared for that some of them won't. They are still so tiny.

That was a good thread, thanks! It was a guy in Sweden even, so if it worked for him, it should for me