When to replant seedlings?

[Andrew Farrell]

This year I planted some espostoa hylaea seeds in may and now have some nice good sized seedlings that I grew using the bag method. When do you think is a good idea to transfer them from the bag to an uncovered pot/planter? The largest is about half an inch tall, almost 3/4 an inch.

[7george]

Replant as soon as possible. This pot is too big for survivors and soil doesn't look good. They need more gritty mix.

[greenknight]

Yes, they're plenty big enough to handle the stress of transplanting, and you need to get them out of that stuff.

[Vipassana]

Nicely done on the seedlings. The baggie method works well.

For future planting of seeds, I would recommend a grittier, much less organic mix from the start. This way you can leave the seedlings in their pot for 1-2 years allowing them to get very established before replanting. I have had great success with this method. I would also plant the seeds much more densely than you would think. I will put 30-50 seeds in a 90x90mm cup. Assuming 40-60% germination, that cup will be pretty dense with seedlings. I don't know why, but seedlings just seem to do better in close groups. Maybe if they're lonely that get depressed?

My seedlings typically stay in humidity contain domes/bags/whatever for the first 6 to 12 months. Rot is rarely an issue because I use basically sand with desert loam and clay chips. When they are 10-20mm I remove the dome and then water from the bottom for the next 6-12 months. Then they get transplanted out.

[Andrew Farrell]

Is my soil mix really that bad? I just used the mix I use for my adults and they seemed to germinate and grow very quickly. My mature plants have a lot of perlite in there mix, but regardless they grew a lot last growing season making me think they like the mix? I’m new to the hobby so I’m having trouble understanding.

[Andrew Farrell]

Also I would like to know how large of a pot to transplant these in to? I used a large strawberry tray when sowing my seeds, but the only pots I can buy around here are 4 inches. Should I go with a pot or try to find a seedling tray or something similar?

[greenknight]

A 4 inch pot would be too large for those, I'd put then all into a 3 inch pot. If you can't find one, a single-serving yogurt container (with drain holes cut) would work.

[toadstar]

I've used seedling trays before without any issue. One cactus per little cell with the soil containing about 50% perlite or other grit.