sowing clematis seeds 

Not exactly, early clematis such as alpina, macropetalas, montanas and Armandii form their flower buds before winter ready for the following spring. Dormant flower buds lie in each leaf joint and begin to swell as the days lighten. Any tidying up before you can see these buds is likely yo result in some lost flowers. Therefore they require no tidying up or pruning at all. Montanas may be cut back immediately after they have flowered if they have started to take up more space than you want them to have. Early large flowered clematis may have some dead material on them which is visible by March or April and you may wish to cut that off to tidy up the plant. It varies from one plant to another but Once you have had a plant for a year to so and become familiar with its pattern of growth you may decide to give it a more significant hair cut. The phrase “ if it flowers before June don’t prune is the one to be guided by. Thank you for watching Ken

You are right in saying that the hybrids will be different to the parent plant. That’s part of the fun, not knowing what you are going to get. I usually don’t bother with Montanas because I have enough of them in my garden. I have grown some Montanas from seed that was given to me from a Wilsonii and the resultant plants were quite different from the parent plant. I find that atragenes are the most interesting to grow from seed and have at least two young plants that are very different from the parents and also different from other hybrids that are on the market.

@@kenblackclematis8272 Interesting that the montanas were SO different from the parent! I’d have expected the differences to be much less marked than with other types. Were any of them worth keeping? Love propagating clematis (always by cuttings so far) but I now have a shoebox of a garden (previous gardens have all been far bigger) and I don’t have room for so many. Will give seed a go later this year. Thank you!

Most garden stores or garden centres sell grit. But you could use anything that excludes light and that the seedling can grow through

vermiculite

Mickey Fraterman awww thank you so much. Is that like fertilizer?

@@rohlatramsbottom2751 No. It is spungy and holds water

Yes it was vermiculite. The exact composition is a mixture of compost or sterilized soil with sharp sand added for better drainage. The seeds are placed in top of this mixture then covered with vermiculite to cut out light. Then a layer of gravel to add stability.

just some vermiculite but this would work OK just with some gravel on top