I prefer to sow in spring and start seedlings off with the same substrate I use for adult plants (2). To prevent it falling through the drainage holes I put a little piece of shade cloth in the bottom of the pot (1). Good results can be obtained by filling the top 5 - 10mm of the pot with fine silica sand and then sowing seeds onto that (3 - 6). After sowing I cover the seeds with a thin layer of medium sand. This allows the roots to anchor themselves quickly and easily. The seedlings stay upright supported between the medium sized sand particles. If you sow directly onto the substrate, a portion of the seeds will land on gravel particles or pieces of bark and for a Lithops seed which is so small it’s hardly visible that’s the equivalent of being stranded on a large rock. If it does germinate it will battle to anchor itself and grow.
Pour the seeds out onto a piece of folded paper (5) so that they can be drawn out into a line and swept off the paper into the pot, using a fine paintbrush. Since my space is limited I like to space seeds individually. It’s a painstaking job especially for a species like L. olivacea which has really tiny seeds but I find it worth the effort. The pot pictured is 8cm in diameter and seeds are spaced so that seedlings can reach a size of at least 5 - 6mm in diameter before they need to be transplanted. Once the seeds are in position I spray them lightly (7) just to get them stuck in place so that they don’t move around when I cover them with the medium sand (8, 9). As a precaution I apply a fungicide once after sowing. Lithops seedlings are the only thing on which I use preventative spraying and this is also the only time I will use a fungicide on Lithops.
Seeds should not be allowed to dry out until germination is complete. I spray them once a day and allow about 14 days before reducing the watering frequency. Sometimes the first tiny plants can be seen within 2 – 4 days.