Lithops optica rubra, hardy to grow?

[Vanzily]

Well, I sow some seeds in april, very good results growing very good four months but for unknow reasons they crinkled and suddenly die. Now I did one order on Mesagarden and I hope to get better results now. I really care very little the lithops, and after they get new leaves I moved them outside with filtered sun, the rest survive very good but this ones... I use scoria and one part humus for the substrate and if I gonna do the sowing this season inside my house in one window until the spring, do you think is Ok?

And in another thing, in june I spend a lot of money ordering lithops seeds in Mesa but no one seed germinate, including dinteranthus, Someone know why ?

[iann]

L. optica 'Rubra' is perhaps a little more difficult than most of the Lithops that people start out with (L. pseudotruncatella, L. lesliei, etc.) but really not hard. In some ways they are even tougher. The two main ways to kill Lithops are: boil them, overheating in a pot due to direct sun and insufficient ventilation; or rot them due to over-watering, over-potting, basically anything that leaves them in wet soil for too long. If they turn white during the day, often with wrinkling, then they probably over-heated. If they turn white or transparent overnight then probably the roots rotted.

To successfully grow Lithops long term, you have to respect their annual growing cycle. Each winter they grow a new set of leaves which will emerge during winter or in spring. The old ones must be allowed to die and then the new ones can grow for the rest of the year. In cool climates this is done by keeping them completely dry over winter and until the old leaves dry out, then watering as needed. In hot climates, you may need to take care because of summer dormancy which makes them over-sensitive to water in very hot conditions. Never be afraid to leave a Lithops dry, even to the point that it shrinks below soil level. They will appear as if by magic in autumn when you can water them deeply several times. In your climate you may also need to water occasionally over winter, just so long as the plants don't become bloated or etiolated from lack of sun, and the old leaves go away each year.

If absolutely nothing germinated, there is always the possibility that the seeds got killed in transit or storage, but most likely your growing conditions were not correct. Lithops seeds germinate easily and completely, and they can be stored for many years. Lithops germinate best in relatively cool conditions, although some exposure to high temperatures can help to ripen the seed. Dinteranthus in particular can be stubborn and won't germinate without going through a period of very high temperatures, but after that germinate well at 20C and below, even below 10C. I would imagine Mexico in spring is not ideal. Maybe try mid-winter.

[Aiko]

Dinteranthus in particular can be stubborn and won't germinate without going through a period of very high temperatures, but after that germinate well at 20C and below, even below 10C. I would imagine Mexico in spring is not ideal. Maybe try mid-winter.

When I sow Dinteranthus in spring and nothing pop up (wich is not unlikely), then I just let the pot dry out, keep it in my greenhouse through summer, and then try again in september by making the soil wet again and putting the pot in a plastic bag to keep it moist. Usually then something germinates after all.

[1bigfruit]

Dinteranthus take a while to germinate. Even Steven Hammers many writings say they are tardy.
Most mesemb seed is up in ten days buy dinteranthus of then takes 2- three weeks. I dont give them any special treatment tbut they do take time.
Be patient they are really easy.

[iann]

Dinteranthus take a while to germinate. Even Steven Hammers many writings say they are tardy.
Most mesemb seed is up in ten days buy dinteranthus of then takes 2- three weeks. I dont give them any special treatment tbut they do take time.
Be patient they are really easy.

Dinteranthus germinate just as promptly as Lithops - if the seed is fully ripe. If not, then waiting might help, or it might not. Lithops seed has a similar period of slow germination when the seed isn't fully ripe, but fewer people ever get to see it.

I find that Lithops seed is poor up to about December or January after the capsule first opens, then fine after that, and doesn't require any special treatment to ripen by that time although it can be forced with high heat. High heat in this context is something like 60C (140F) which seems a lot but is quite natural for a Lithops in the sun under glass. I don't have the equipment to accurately measure the temperature of the capsule so that is the temperature of the Lithops body. Dinteranthus seems to need sufficient heat to ripen the seed, and may not always receive this in cultivation in the UK.

I have tried the technique of germinating at high temperatures, which has been described by Hammer for very fresh or "difficult" seed including Dinteranthus. My experience is that seed will not germinate at high temperatures, but often germinates almost immediately when the temperatures are returned to more normal levels afterwards. In naturally variable conditions, or perhaps even where days are hot and nights cool, this may not be noticed and the conclusion could be that germination requires the high temperatures.

[promethean_spark]

I have L. optica rubra among my other lithops and haven't had a problem with them. I think they did shed their old leaves either a month earlier or later than the other lithops, but they're doing okay in a common pot with other 2yo seedlings.
Lithops meyerii 'hammer ruby' is similarly red (at least when small) and hasn't given me any problems either.

My lithops are getting ready for sleep now and will not get water until March/April. They really look like they're dying in early March (actually the old leaves are dying of thirst), and resisting the temptation to give them a drink at that point is the only tricky thing about growing them.