DAHLIAS BY DESIGN

Many British dahlia breeders who are also members of the NDS have aired their views in the pages of NDS publications, but we mustn’t assume our members, or indeed dahlia growers in general are all looking for exhibition type flowers, or as I once heard them referred to as “Flowers on sticks” Most people want to use them for garden use. Therefore there are many options open to the budding dahlia breeder. For instance, dark leafed cultivars are an asset in the garden even before they flower, and a number of excellent cultivars have been bred by Jack Gott  http://www.jrg-dahlias.co.uk  His basket displays of dark leafed singles at shows around the country are often voted as the “People’s Favourite” Another type popular with the general public is the dwarf bedding dahlia, some of which are only twelve inches high. The Verwer brothers from Holland http://www.verwer-dahlias.nl/ have a range of these under the title of `Gallery’, which surprisingly enough isn’t a new group name, but a trade name of a section of their output.

In the USA the dahlia is used extensively as a cut flower, and we all know how well equipped it is to do the job. So when Bob Hendley, a great friend of mine who has a new dahlia nursery here in the South of England called Fontmell Studio, repeatedly tells me there are only 2,500 exhibitors in this country, and 10,000000 general gardeners who love to grow this colourful hybrid. I know he’s right when he says that there’s more than one use for the dahlias we breed. Even so, most breeders dream of producing a dahlia that will take your breath away, and also win honours on the show bench, but how does one achieve this? If you have the space and inclination you can sow and plant 1,500 seedlings, and end up with a mountain of spent dahlias, and maybe twenty or so reasonable seedlings which are given the chance to flower the following year, but those of us with limited room have to resolve the situation by using a different method, which results in a greater proportion of seeds that produce good dahlias. Obviously the most scientific way to breed dahlias is by hand pollinating. True, not all cultivars are compatible, or find it easy to conceive (a bit like some humans really!). Others seem to find it hard to produce seeds even though they make plenty of pollen: that old fimbriated (laciniated to our North American friends) Frontispiece comes to mind. On the other hand, sometimes the opposite happens and poor pollen producers can still make seeds. Let me cite one of my 2004 seedlings called G. I. Joe. It was produced by hand, out of a cross between Hamari Gold (Giant Decorative) and Cornel (Small Decorative). Strange bed fellows, I can hear you say, but that was the only pollen available at the time, and also in the days before I started storing pollen in the fridge. Anyway, though G. I. Joe isn’t a world beater it does have the giant DNA in its make up, even though it’s just a medium decorative. I’d been planning to cross it back with its larger mother, but I found it had little or no pollen, so I decided better of it. Therefore, imagine my delight when I broke off what I suspected was an empty un-pollinated pod one day last month, and found nine very large seeds inside. I had no dealing in this miracle birth: Was it the work of Mr. Bumble or an example of (supposedly impossible) self-pollination? G.I Joe’s vital parts are way down inside the spent head with the sepals hiding it completely. I don’t suppose I’ll ever know: But at the time of writing this article, I’m anxiously waiting for next year so as I can sow the seed, and see the resultant flowers open. Don’t get me wrong, there’s nothing bad in letting the bees do it after all they’ve been doing it for a few million years so they should have picked up a few wrinkles by now. Leaving it to the bees can give you some great new cultivars, especially if you have several dahlias of the same group growing adjacent to each another, well away from other groups. The late great Eddie Durrant bred superb cultivars such as Kiwi Gloria using the group method, but I expect he chose his cultivars well, and did isolate them from other groups. I’m certain that if you do decide to leave it to the bees and you grow every conceivable group including Collerette’s and singles in close proximity, and you’ll soon be producing new dahlias in the form the good Lord intended them. I’ve always known that hand pollinating is the only way to be sure the resultant seedlings are from the actual cultivars used.

	A Bee doing what Bee's do.		The open flowers of a Colleret.		And with the outer ring of stigmas open.

The thing that puts most folk off hand pollination is the time it consumes, “Okay when you’re retired” they say, but don’t expect that when you put down the pen, pestle, paint brush, or shovel that you’ll get more time, because that is when the time really whizzes by. So how do you go about producing winners, whether for show-bench or garden use? I suppose the most time consuming thing is to find compatible cultivars. This isn’t such a problem with smaller cultivars, but when it comes to the giants, believe me the problem is multiplied a hundred fold because some giant cultivars have a jumbled mass of breeding tubes, and by the time you’ve found the stigma it’s either given up the ghost, or there is no pollen present. Of course there are cultivars that produce pollen readily, and these are the cultivars the novice hand pollinator needs to use. The kindest thing you can do to help a dahlia flower produce seeds is to remove the petals when the flower has reached the “full blown” stage. Be careful not to leave any broken ends in what will become the seed pod, because this will certainly give it every chance to rot before the seed is ready to harvest. Treat the parent plants (seed parents and pollen parents) in more or less the same way as you treat any dahlia, but keep them a little dryer, and a little less well fed, this will help stimulate better pollen and seed production. When a flower is finally prepared to be used as a seed parent, it has to be covered up before the stigmas push through the anthers inside the corolla tubes, and are exposed to the outside world (and the bees). I’ve used many contraptions to cover the prepared bloom to stop it being pollinated by an insect. One of the best was made from those bags which have thousands of holes in, and are frequently used to cover loaves of bread, but in the photo below Wayne Holland used the bottom half of a pair of tights.

I always avoid polythene because it is inclined to sweat which would be disastrous. So we have secured the flower that we are going to use to carry our seed, now it is the turn of the pollen provider, which is prepared in exactly the same way. You must wait again for the flower to reach the full blown stage, and before the pollen laden stigmas have pushed through the corolla tube. The pollen parent needs to be slightly behind the seed parent to allow for the seed parent’s stigmas to open fully. The most reliable way to get uncontaminated pollen is to isolate your pollen provider, either on a sunny window sill (in a vase of sterilised water), or in the safety of a greenhouse, away from the persistence of Mr. Bumble and his mate Master Hoverfly.

The last stage of the all important union is to introduce the pollen laden flower (the male) to the seed carrier (the female) by gently pressing the two together. Most breeders say midday is the correct time to do this, but having watched the bees on countless occasions I’m sure this isn’t the only time the job can be done. As soon as you’ve done the deed, place the pollen provider back into water away from marauding insects, to build up another crop of pollen, and repeat the cross the next day in case the first was not successful: okay you might be successful at the first attempt, but it’s better to be safe than sorry. If the cross is viable the stigmas on the seed parent will shrivel and die soon after pollination. In a few weeks the seed pod will form and, although still green, you will know you have at least some seed inside. Now is the most risky time for these immature seeds, because to leave the pod with all the old pollen and moisture inside is courting disaster: they can easily rot. It is so easy to remove the old pollen: hold the pod between first finger and thumb, and squeeze gently. You will see the old pollen and moisture tumble out. Do this every day until no more moisture is left inside, and then you’ll know that your precious seed is safe until it is time to harvest. This will be when the pod turns from green to a more golden colour. Now what I’m going to say next may raise a few eyebrows, but here goes. In the past I have put the stems that hold the pods in water, then waited until the pod dries completely and starts to open. I no longer do this, especially when I’m working with giants. Instead I wait for them to dry partially, and proceed to strip the seeds (when they’re turning black) from the pod, drying them off in a saucer. I do this because if pods are left too long in an autumn greenhouse you can lose some from fungi attacking the damp seed, and you wouldn’t know until the middle of March when very few seeds germinate.

So I have given you my thoughts on hand pollinating, and its various stumbling blocks. Likewise you know the thoroughness of our flying friends in their search for the sweetness of a flower, so why not compromise, and try both methods? I can’t begin to tell you how much pleasure I get from producing a new cultivar. Mind you 2006 was a pretty disastrous year with temperatures down South hovering in the high thirties during June, July, and August. Much of my breeding stock was decimated by two of the most debilitating enemies of the dahlia grower, red spider mites, and mildew. This was all brought about by the dry hot summer, and made worse by the location where the plants were grown. Most of the breeding pool was grown in ten inch pots, and because of a lack of space they were placed against any available wall. Fatal because, as you know, walls hold heat, and there is nothing red spider mites and mildew love more than a hot dry environment. Try as I might (do you get it?) I could not rid myself of this infestation; it was heart breaking to watch formerly healthy plants have the life blood drained out of them. But, as any dahlia grower can tell you win some, win, and you lose some! Telling you how to hand pollinate is ironic really, as in the future I intend to use the services of Mr. Bumble a little more than I have in the past, as my dear wife Irene has been diagnosed having Osteoporosis, which means I am needed in the house more than usual. So in order to compromise I intend to grow my pool of breeders in blocks of six cultivars belonging to the same group at strategic points around the garden, and wherever possible have only that type of flower in the same location. I will also increase the spacing to try to get healthier plants. I should have enough time to keep an eye on what the bees are doing, and to give them a helping hand when necessary.

In 2007 I am hoping to find out more about dominant and recessive traits in the dahlia. This is a whole new ball game which until now I’ve been unable to grasp properly, though this hasn’t stopped me from enjoying a fascinating past time, and have a modicum of success. Okay, my friend Bob at Fontmell Studio loves the excitement of not knowing where the bees went to produce the new cultivars he gets, and believe me he gets some crackers, but imagine the extra satisfaction you get when you know which pairing gave you that belter, and knowing you can repeat that particular cross again and again with a different result each time. Speaking of Bob, I knew that if I was successful with my breeding I would need an outlet, somewhere for my seedlings to be trialled and brought into the public domain. Where better than on a Southern nursery run by this ex-guardsman from Yorkshire, who spent his childhood helping his father grow and stage some of the finest dahlia displays in the land? Last, but certainly not least I must mention his lady Linda, or Lin as she likes to be called. She is a fantastic graphic designer, and with her expertise over the years produced what I believe is one of the best glossy colour catalogues there is. My new cultivars certainly look the bees’ knees in their catalogue!

So if you really want to breed dahlias by design I can assure you there is no better way than using the hand pollinating method, because just like your kids you’ll see both parents in the offspring, and as you get more and more knowledgeable you will know which cultivar to try next, unlike Mr. Bumble. I rest my case. Just before I sign off I’d like to tell those of you that are interested about a new breeders club I set up on the Internet at the beginning of the year called Brush or Bee. To become a member, which incidentally is completely free, copy the following Internet address next time you login! http://tech.groups.yahoo.com/group/dahliacreating/ you’ll soon find yourself conversing with some of the best dahlia breeders in the world, sharing tips, photos, and experience.

By the way I must thank Wayne Holland, John Menzel, and Geoff Hoyle for the photographs.

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