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Tuesday, July 10, 2012

Jean Stevens and Keith Keppel on BREEDING BEARDED IRISES




BREEDING BEARDED IRISES

By Jean Stevens
Bastia Hill, Wanganui, New Zealand.

One of the prime urges of the gardener is the instinct to create, when his garden is gay with flowers he will show you around with an air that says 'look at what I have achieved by my on labour, and my own planing!" This instinct to create reaches its highest fulfilment in the raising of new flowers. Then may he justly claim, "Look at what I have created!!"

I should like to make an appeal to every iris grower to raise a few seedlings of his or her own every year. Our chosen flower is one of the simplest and most-rewarding to raise from seed. The Tall Bearded Iris in particular lends itself to the amateur hybridist, be he novice or experienced gardener. We who raise new Bearded Irises have almost everything in our favour. We do not need to cover our flowers after pollinating to prevent pollen carrying insects from upsetting our planned crosses. We have large blooms which do not require expert fingers and fine handling to do the pollinating. We can, and in fact should, raise our seedlings in the open ground. If we use modern varieties we are certain of good results. And lastly we do not need much space to raise and flower a nice batch of seedlings, which, under ordinary garden culture, will flower in 15 months from date of germination. And here is a lure! The finest irises raised in the world have been bred by amateurs. Are you interested? Let me go back and enlarge on the statements above.

First, as to my claim that pollinated blooms do not require covering from bees and insects. In the evolution of the flower through the work of past hybridists the tunnel like entrance between the style arm of the flower and it's fall petals has become almost closed to bees, which if they do persist in trying to extract the honey, almost invariably push in sideways at the base of the flower, thereby they do not go near the pollen or the stigma at all. Insect's smaller than bees do not carry the large pollen grains, and even if they did so have no cause to visit the unusually placed stigma. A glance at the tracing will show the uninitiated where these vital parts of the flower are placed, and convey my meaning clearly. Occasionally by chance and Iris flower may become fertilised but this is the exception and does not worry the hybridist, who in any case chooses a freshly opened flower upon which to make his cross.

The flower of the Bearded Iris is large in all its parts, and personally I use neither camel hair brush nor tweezers when pollinating my blooms. Certainly a brush is superfluous. The job may be done more easily, more certainly, and without any risk of damaging the stigma, by extracting an anther from the pollen parent, and holding it by the tip, brush the pollen grains directly on the stigma. If any difficulty is experienced in grasping the anther to remove it, tweezers may be used, but very little practice will make it easier to use fingers than tweezers.

Irises do not like the confined air of the glasshouse, though some breeders do raise their Iris seed successfully in a house, transplanting to the open ground shortly after germinating takes place. Others find raising the seed in pots or seed boxes outside makes for easy weeding. When I first raised Iris seed I used this method, but have long since discarded it for sowing in the open ground. Top dressing the position with sand to the depth of half an inch where the seed has been sown overcomes the weeding problem, and open ground seed sowing has the important advantage of making it easy to keep the seedbed evenly moist during that five or six months that the seed has to germinate. To get good germination it is necessary to sow the seed as soon as it is ripe, that is about February or March, but except for an odd seedling, germination does not take place until the following spring. Needless to say, it is necessary to keep the seedbed free from weeds. If weeds are allowed to grow over the seabed they will bring up the seed when pulled out. If allowed to grow amongst the germinating seed in the spring they will draw up the young seedlings which will then suffer badly on transplanting. Sow the seed quite thickly, about ¾ of an inch in depth, in a well-prepared soil. We are the soil is at all heavy it is advisable to place sand both below and above the seed when sowing. This allows good soil aeration which is necessary to germination. Only a proportion of the seed will germinate the first spring, and if the cross is a good one the seed bed should be sanded over again and kept weeded for a second germination the following spring. When the seedlings are about two or three inches in height, which is about the second week in October with me here in New Zealand, they should be carefully lifted and immediately planted out in rows. About seven or eight inches is sufficient space to give them between seedlings, with the space between the rows just great enough to allow cultivation and weeding. In dry climates, or very light or sandy soils, the young seedlings should be well watered following their shift to the open ground. Thereafter the hose should be kept going to ensure quick growth. The growth made before Christmas will determine whether or not the plants will flower the following spring. Here I should like to give a warning. If the young plants are not transplanted before the end of November they are very unlikely to flower the first spring, and would then need to be grown another 12 months before they do flower.

Good garden varieties are sure to be found amongst any batch of seedlings if only the good modern Iris is used as parents, particularly if the parents are chosen with some discrimination. By good modern Irises, I do not mean the most expensive, for there are many varieties amongst the two and six penny class, which will give excellent seedlings. Naturally if we have set our hearts on raising the new pinks with tangerine beards, or some of the brilliant new tan and copper shades we must work with these expensive parents. But the would-be hybridist, making his first crosses, should not attempt to run before he can walk, and content himself was doing some less ambitious crosses which will be certain to give an appreciable modicum of success. Never put through indiscriminate crosses. It cost neither time nor effort to decide what colours you want your seedlings to be, in fact this is part of the pleasure of raising seedlings. Do you want to raise a real blue Iris? The perfect blue Iris is yet to be raised, and you choose your Iris parents carefully you may become the raiser of this long desired and worked for flower. Do you fancy a tall rich red without haft markings, or a rich golden yellow? Or perhaps an exquisitely formed and frilled tan blends.

For blues one has to choose either two blue parents, or one blue and one white parent, if one is to be certain of producing blue seedlings. Reds can be produced in several ways, by crossing two red varieties, or a red and a yellow, a wine and a yellow, or a copper and a yellow. Whites may come from white, blue, or cream parents. Tans are raised from copper and yellow, pale blue and bronzes, or gold and wine crosses.

Since this article is written primarily for the novice breeder, perhaps I should describe the actual mechanics of crossing, or pollinating. The vital parts of most flowers are obvious to the casual glance. We learnt at school where to look for the pistil which carries the stigma at its extremity and for the pollen bearing anthers. We know the stigma receives the pollen and carries the new germinating cells to the female organ where the seed is developed. But the vital parts of an Iris flower are not so obvious. The flower is divided into three distinct parts, each carrying a separate stigma and pollen anther. Take an Iris flower preferably one which is past its fresh beauty, and carefully and separately pull off the standards or upright petals. Now as carefully detached the fall or hanging petals. You will find that you will hold a stiff three pronged flower centre. At the outer of each prong will be seen two small upright points which are called crests. Directly below these crests is a little lip, and this lip-the upper surface-is the stigma. Now look under the prong, which is called the style arm, and you will see the anther closely hugging the under curve. This anther carries the powdery pollen which is easily brushed off. To make a cross it is not necessary to pull the flower to pieces. The pollen bearing anther can easily be pulled out from under the style arm of the flower chosen as pollen parent, and carried to the flower which is to be the seed parent. Lift the crest on the style arm, and very lightly brush the pollen grains on to the upper surface of each of the three stigmas. A tag should be tied to the stem noting both the seed and the pollen parents. Not all pollinated flowers will set seed, and to ensure you have some seed to sow, several flowers should be pollinated on each stem, and several crosses made. To get the greatest interest from your crosses every cross should be separately labelled when sowing the seed. When the seedlings come to flowering you will have a thrilling experience watching them open from day to day, and great will be your joy in your own creations. But, and this is a very important "but", keep only a very few, perhaps only one or two of the best, and ruthlessly discarded the lesser lights. If you do not discard the greater part you will find you will soon have no room for next season's crosses, which will probably be much better than your first efforts.
First published New Gardener 1946
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TIPS FOR PLANING YOUR HYBRIDISING
Keith Keppel
Salem, Oregon

First of all, one thing in Jeans article I would stress is...that if planting direct in the ground, you can have delayed germination for years, so to keep from contaminating your later crosses you need to move to a different area or fumigate the seed bed to kill any un-germinated iris seed. That is why I always plant the seed in pots filled with fresh soil.

Program 1) Set a goal, something "different", and try to work out a plan of action to get there, then make the beginning crosses as per plan.

Program 2) Also cross a few pretties...same color group.
When the seedlings from program one bloom and are god-awful, the pretty things blooming from the conventional crosses will help keep your interest going.

From the program one seedlings, let THEM tell you what way to go. Tangents are often far more fun than the original project.

Only do as many as you can handle without undue stress, do not expect fame or fortune, but enjoy each and every new seedling in its own way, as each will be....somehow....different from all others, and you are the first one to see them.
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The above photo is of a Keith Keppel seedling that he has described as "a good example of something unique......like combining a plicata with one of Jean Stevens yellow amoenas!"

Huge hat tip of course to Keith Keppel and the Late Jean Stevens.

Photo copyright Keith Keppel; Copyright Iris Hunter

1 comment:

  1. Thanks for a great article, very interesting and informative! I was recently shooting video of irises at the Marsh Botanical Garden at Yale University when we ran into Dr Kenneth K. Kidd, Professor of Genetics, of Ecology and Evolutionary Biology and of Psychiatry at the Yale School of Medicine who dabbles in breeding bearded iris and he graciously agreed on the spot to show us how he does it. Your readers may find this video to be a useful visual aid to support your excellent article. http://youtu.be/-jRvotqV2ZQ

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