I find this one to be rather odd. It self seeds around, but I have never managed to get seeds to germinate in potting compost.
This is the advice given to me by a friend some time ago.
Sowing Advice

Cover with compost or grit 2mm deep in a cool spot if possible, or a cool bright position outside. Please note: this seed is a cold/cool germinator and after sowing will usually not germinate if kept above 14 degrees C. Grow on individual seedlings in 3” pots. Plant out in a well-drained open and sheltered position or in a large pot in a conservatory.

well hello you, lovely to see you.
I will ask around my various garden friends to see if we can get you some seed or plantlets.

Thanks so much both. I enquired on Google and managed to get a few seeds a pkt of 5 for £3.99 plus postage £3.
and another pkt of 12 for £3.99 free postage both from E bay. My their scarce one of the providers even asked if anyone had them in their garden could they send them some seeds they would be gratefull they are so scarce and rare these days. Wow, that gave me insentive to have a bash. I have got them in a cold garage window where the sun wont get on them it said keep below 14% well its 16 at the moment but as winter draws in that will come down, but will watch the hard frost . I think I sent you one Seaburn so obviously you lost yours also. Seeing we are having milder climates these last few winters I thought i'd have another go. Since my accident has given me so many irons in my leg I am very resticted, but still keep my large garden going some shape, not what it used to be, with the help of a visit 3 times a year by a garden firm to cut back all my shrubs and trees at the correct times. So lovely to see you are still very loyal to GYO site. I use to
love it. Hope your family are keeping weel. Thelma

I started mine from seed sown in the spring. It was easy and loves mild winters (since the Azores is very close to the temperatures in Madeira where this comes from) to the point of being invasive. I used regular potting soil and temperatures around 60° - 65° F.

Thanks Wyleithea that was very informative of where its from and tempratures etc which I had no clue about. It was such a lovely plant when I had it, and no time to think about it for a number of years. I was so suprised to hear it has become so rare. I have planted mine so will take great care to get it germinating over the winter,

Thank you for asking this question Thelma ... what a gorgeous plant. Inspired by you I have just bought seed from Chiltern (3.45 for 20), so will be optimistic, and follow Owdboggy's instructions. Maybe try them in my cold frame? Definitely worth a try for that size and colour!

The trouble with Geranium maderence is that it can be monocarpic, tending to die back once it flowers. One of the reasons that it is not all that popular or readily available.

It does die after setting seed, but it sets so many seeds that it becomes almost invasive. It should be treated as a bi-annual.