General growing questions

[Spikylover]

Hello everyone
Let me start by saying you all have great seedlings! However, this is making me jealous how on earth do you get them so big so fast? Your 3 month seedling are as big as my yearlings and your yearlings are bigger than my 2 year olds.
1. Lighting: i think i have this part sorted out
2. Soil: what do you use? I use a high grit content soil. Im thinking i should use a more water retentive soil but after the seedlings are our of the baggy, it will take too long to dry between waterings. Thoughts?
3. Repotting:
a. When do you repot? I see people repotting tiny seedlings regularly and people advising to leave them undisturbed as long as possible. I'm confused
b. Repotting aftercare: i think the airy gritty mix does not help seedlings settle with their tiny roots since sometimes there is air space between the roots and the actual soil. How to remedy that? More soil/sand? Smaller size grit?
4. Fertilizer: do you do that?
5. Heat: what day/night temperatures do you set? Is 15-18 at night too low? Should i go for 20-25?

Thanks for helping me figure this out

[keith]

b. Repotting aftercare: i think the airy gritty mix does not help seedlings settle with their tiny roots since sometimes there is air space between the roots and the actual soil. How to remedy that? More soil/sand? Smaller size grit?"

I use more sand for smaller seeds. My usual High grit soil with more sand .

a. When do you repot? I see people repotting tiny seedlings regularly and people advising to leave them undisturbed as long as possible. I'm confused"

only if I have too like mold is in the pot. usually a couple years until transplant but they still might be small.

4. Fertilizer: do you do that?' No

5. Heat: what day/night temperatures do you set? Is 15-18 at night too low? Should i go for 20-25?"

probably depends on the kind of cactus seed. The lower temps look ok to start if no germination you can try hotter.

[theJrnyconts]

This is what has worked for me in limited space and resources. My top advice is to take what you have learned and mash it together to find what works for your circumstances. Nobody has the be all end all when it comes to this. For example, I was told my cali barrels are in too rich of soil and they would be dead in weeks. That was 5 months ago. Meanwhile my pineapples are in amended soil and they are almost completely dead. My next best advice is to research the native range of your seeds and try to mimic that habitat to the best of your ability.

Soil- I use 50 perlite, 25 cactus mix, and 25 fine sand. It has given me the best results of the different mediums I have tried. I've done cactus soil, regular dirt from outside, and peat moss. My cali barrels in cactus soil gave me 6 with four still alive. They are happy as can be, but the poor germination rate I think has more to do with seeds than soil. Giant saguaros do NOT like peat moss at all. Organ pipes and beehives do ok, but after learning about cactus seed growing, I'll never use peat again.

I've been told the earliest is six months. However, I'm leaving them alone since most of my seeds are very compacted in the containers they germinated in. My route is going to be leave them in for as long as they can be. Outside of my saguaros, they will have gobs of room to grow and there is no reason at all to disturb them. When I transplanted my ocotillos, I lost 33% of them. 10 out of 30. Since they grow so fast as babies, I won't plant them in anything other than their own planting cell. Easiest plant I have ever grown and that includes veggies. I'd wait until it was absolutely necessary. Nothing, people animals, plants, like to be moved around so let them be is my method.

When I plant my older cacti, I always go with a very amended cactus soil. I add a lot of perlite and it drains amazingly well. That is all I will do for my seedlings when they are ready. What I think is more important is to remember water amounts. Where I live, the wild cacti are growing in clay. However they don't get a lot of water down there so they get drenched for a week and then nothing for months. I am more concerned with the amount of water I give rather than the type of soil. The plants I have in a sandy clay mixture are doing far better than the ones in a pure sand. Both get whatever natural rain water falls.

I don't fertilize anymore. I didn't dilute it enough and they started growing very funky. If you're going to do it dilute it about 20 times more than what anything says and you'll probably be fine. I've been thinking about using Alaska fish fertilizer. ground up fish is much better than miracle gro or something similar.

When my seeds were germinating I had my mat on at all times and it doesn't have a thermostat. I don't know what it is set at. All I know is that when I started trying to germinate seeds with fluctuating temps, they didn't germinate at all compared to when they had a constant temp. My Mammillaria aureilanata var. alba didn't start germinating until the mat was on 24/7. This kept the humidity and temperatures up all the time and they took off with germination.

And you didn't ask anything about this, but its something I learned is pretty important to some species and gave me great success. Sclerocactus and pediocactus species have to have cold stratification. I've heard that echinomastus also need it, but I don't have the room right now to try more. For those that I did an artificial winter, I got 7 out of 15 seeds to germinate. Unfortunately only 2 are left. The ones I did outside for winter, 0 germinated. My echinomastus seeds didn't have cold and I only got 1 of 10 to germinate. I'm going to give them the cold treatment.

Best of success.

[Vingames1]

Probably the best thing is get them in natural sunlight . You will see a lot more growth when you do. Also I fertilize mine once a month and it helps

[7george]

2. Soil: what do you use? I use a high grit content soil. Im thinking i should use a more water retentive soil but after the seedlings are our of the baggy, it will take too long to dry between waterings. Thoughts?
Too long? It depends on pot size (my pots are smaller) and air humidity. One week is not too long, also during the growing period do not let that soil mix to get fully dry, water when is slightly wet deep inside.

3. Repotting:
a. When do you repot? I see people repotting tiny seedlings regularly and people advising to leave them undisturbed as long as possible. I'm confused
Repot first time shortly after taking seedlings out of the baggies, after - at least every year.

b. === Smaller size grit?
Yes, I use smaller size soil mix for seedlings then for grown up cacti.

5. Heat: what day/night temperatures do you set? Is 15-18 at night too low? Should i go for 20-25?
Preferences are different for different species, but when I set minimums at 18 - 22 C most grow much better.


I also have lot of seedlings grown at room conditions and it takes many years to them to reach decent size but I'm not worried by this.