This is definitely NOT one of those 'how to' posts, and is probably more of a 'how not to' ! This is about an absolute novice, groping blindly in the dark, hoping that somebody who DOES know, will come along and give good advice!
My brand new obsession is learning how to hybridise dahlias ... with only the internet as my guide !
I regularly give thanks for the internet, and I gave them again, when finding that knowledge of the alchemy of hybridisation was only a click away. I read that dahlias are a good plant to start with as they are so easy. Easy! Organising plant sex for unsuspecting plants is certainly not easy!
The first step, according to the various websites I consulted, is to identify dahlias which have a characteristic you like.The advice is to breed for only one defined attribute. After a wander round the garden looking at all my dahlias, the choice of two special ones was made easily. Out of the packet of 'Bishop's Children' seeds I sowed in Spring, there is a plant with wonderful orange, stripey flowers which has caught my eye all season (see photo at the top of the post ). I like the stripe and would like to enhance that characteristic, but feel that the colour is a bit washed out, so ideally would like a stronger, darker colour. The other dahlia is a lovely rich magenta with very dark foliage, which I think is 'Magenta Star', but I couldn't swear to it. The colour just zings, and contrasts so well with the yellow stamens. If you look at the petals carefully there is a stripe of darker colour down the ribs, which I hope will become much more marked if there are any offspring. What colour do you get if you mix magenta and orange ? Probably a sort of muddy beige, knowing my luck! I shall have to wait and see, like the total novice I am !
So, once the parents have been selected it is a little bit like IVF I suppose ! A male flower has to be selected with very visible stamens and pollen, on a fully open flower. Once that is picked, with a nice long stem, it needs to be labelled with its attribute (i.e. 'stripy'!), and taken indoors to have its petals removed. It is taken indoors to stop the pollen being taken by insects and/or contaminated with pollen from other plants. The selected flowers have to be at different points in their development, in that the male flower needs to be fully open with visible stamens, whilst the female flower should not be completely open.
I tested this male flower by touching it gently with a cotton bud to see if there was a lot of pollen on it, and there was!
Poor things look so denuded !
The next step is to select the female flower, and I chose it with the same attribute as before - 'stripey'. My internet notes state that the female flower should not be fully open when selected. The female flower is not cut, but is covered by a little hood, to shield it from pollination by insects. The hoods can be made from nylon tights, pop sox or stockings which allow light in, but keep pollinating insects out.
Once the female flower is completely open, and the stigma are showing, then the little hood comes off, and all the petals are removed.
(nb The female flower in this photo is not yet open enough at this point - one of my early attempts doomed to failure !!)
Then comes the plant sex, where the male flower is pushed into the female, and the stamens are rubbed, both ways, across the stigma. As much pollen as possible should be transferred at this time. The hood is then replaced to stop further pollination from insects and the whole process is repeated the following day.
After three or four weeks the seed head should have formed, all being well, and it should have turned from green to a light straw colour. The seed head can be removed at this point, and when it is completely dry the seeds can be removed by hand, prior to planting the following March.
The back end of September is not the best time to develop a sudden interest in hybridisation of dahlias, as, firstly, there are fewer flowers now than there were earlier in the year, and secondly, everything is soggier than it was, so there is more chance of mould and rotting. I don't think my chances of developing a new and wonderful dahlia are very high at all, but it has whetted my appetite for next season, when I will have more time to practise these new dark arts !