What is the best time of year to plant my seeds indoors?

[ragamala]

All the species you list will need quite cool nights, or they may not germinate. It is common for them to be too warm under lights..

I,d assumed that, like me, most folks grow or sow under lights with a time switch, so that shouldn't be a problem?

[BryanW]

All the species you list will need quite cool nights, or they may not germinate. It is common for them to be too warm under lights. A south-facing window is often more successful. If you can keep it cool enough, extra light can be useful until there's some real light in a few months time.

They should all germinate easily, some are a little more tricky after that. The Titanopsis and Dactylopsis are winter growers that are tricky in our climate. The Dorotheanthus is a vigorous weed that will etiolate badly in warm dull conditions. The Conophytums you'll have to take care with because it will be very small when it goes dormant for its first summer, but otherwise not hard.

Many thanks for the reply Iann.
My main growing windows are SSE facing and even now in January they get sun until around 2pm and the windowsill propagator reaches a temp of up to 32c if the plastic lid is left on during the day (cover off = 20-22c). At night the temp goes down to around 16c and if I open the window vent and tuck the curtains behind the radiator it can be as low as 8c with cover off the propagator.
I tend to tilt the propagator trays slightly during the day so as to maximise heat dissipation in the substrate and to prevent the seedlings leaning and becoming leggy, I would imagine this would be beneficial in germinating Lithops and Conos.
I do have an outdoor wooden grow box which is covered with an opaque growing tent and it could be the ideal place to raise the Dorotheanthus seedlings once germinated and grown to a decent size, that box usually retains a temp 2-3c higher than the surrounding atmosphere at night and gets full sun from March onwards. I am used to plant failures so I won't be too disappointed if they don't reach maturity. Spider mites and other pest are usually a problem in the out door grow box though.

I have read today that the Tanquana seed germination is improved by smoke? It wouldn't be too difficult to run wood smoke through some silver sand, if required.

Unless when sown in spring, it will keep on growing during its first summer and will not go dormant about one full year later in the next summer. And in the mean time you could treat them during their first summer as any other summer active little seedling.

I'm beginning to get the idea, that if I leave the lid on the Conophytum batch of seeds during the day and remove it during the night I should get good results and vice versa for the Lithops. Am I wrong in thinking that way?
The window sill has good ventilation on sunny days!

By the way I have the 'Ed Storm's 'the new growing the mesembs' book on order, hopefully that will put me right too.

PS the LED lights are an 81watt bank in an aluminium channel 85cm long and they are much brighter than the bayonet bulb type that I've tried in the past, safer to touch too.

[BryanW]

I've found some Dactylopsis digitalis germination info from a SA enthusiast on a forum who states their germination method. Which I'm sure I can manage/ duplicate easily later in the year (if the seeds are viable and actually what they're supposed to be).

Initial temp night 18C (64F) day 25C (77F), 13.5 hours daylight,

One other thing 50% seedling soil/50% riversand, sterilized with 3% hydrogen peroxide (I just flush the soil in the tray, let it drip dry, and sow seeds, cover with thin layer of riversand)
Credit https://davesgarden.com/community/forum ... id=8564069

I've also read this too viewtopic.php?t=165580

[Aiko]

With Dactylopsis it is not getting them to germinate that is the problem. It is the stages right after it.

[BryanW]

Did you have any luck in keeping them alive Aiko?

[iann]

Overall, I'd be looking at 22/8C as a good starting point. You can go warmer and may get good results, but go too hot and lots of mesemb seed won't germinate (some might, anecdotally with very high temperatures, but my experience as been that they germinate *after* the very high temperatures stop).

Although you can successfully start mesemb seed under cover, as I do, and even for weeks after, it is usually best to give them good ventilation from an early age. Sun (or strong LEDs!) can be beneficial but watch out for overheating which can be rapid and fatal. Lithops are particularly prone, but any very small mesemb can suffer. Symptoms are rapid bleaching to white or transparent. Rot can look similar, but the conditions are usually different and obvious.

Soil doesn't seem to matter much, anything that is gently moist plus high humidity for germination, or a little more moist out in the open. As mentioned, growing on is usually the hard part with mesembs.

[BryanW]

Cheers Iann, I'll give those conditions a whirl, It's becoming apparent that I've a lot to learn about Mesembs in general, especially Northern hemisphere cultivation methods. All I have to do after that is keep learning