Don't worry. Normally they are perfectly hardy and would be fine outside all winter, as are all of mine. However, buying a plant at this time of year that has been greenhouse grown probably means that for the rest of this winter it is better sheltered from the coldest of the weather. So put it out during mild spells and only bring it in if you have 3 or more degrees of frost predicted. It should be fine.

As regards stamens dropping off, that's part of the natural progression of the flower. Either it has been pollinated, in which case you should see the seed capsules swelling or, it hasn't and the flower is going over naturally. If there are more buds and you keep the plant inside then you will not have much chance of seed unless you do some pollination yourself. The stigma is receptive from the time the bloom opens 2 or 3 days before the pollen ripens on the stamens. (This is what encourages natural hybridisation as bees will visit as soon as the flowers open carrying pollen from other plants.) Use a small soft paintbrush and collect pollen from one flower and dust the end of the stigma, alternatively use a pair of tweezers to pluck a stamen from one flower and using this like a miniture make up brush, apply pollen to the stigma. This will give you good practice for hand pollination later when you want to make specific crosses. I usually tie a label loosely round the neck of the flower pollinated this way with the parentage(donor) details, discretely marking it with a piece of wool tied loosely round is less conspicuous.

If you are being really thorough and want to be certain of the specific cross you would emasculate the bloom, ie pull all the rest of the stamens off and put a muslin hood over it, (toepiece of a stocking will do, let light and air through but not pollinators). However at this stage for your new plant, I should be happy just to pollinate one flower and leave the rest to nature.

You should get an indication of how many seed you would get allowing nature to run it's course via visiting pollinators. Generally very few on the first blooms of the season, and more as time progresses and there are more blooms and pollinators. Artificially, you should get 10-20 per bloom.

Details for harvesting and sowing the seed are elsewhere here, just plant fresh, you'll probably get near 100% germination.

Have fun.

Greenmanplants

Thank you so much for that information - I hadn't thought of pollinating the plants myself - but I am going to print out your instructions and try this weekend!
Jakki