Gardening 15: 348 (Aug. 1, 1907)
HYBRIDIZING
John Cook

A paper written by John Cook, of Baltimore. Md., and read at the meeting of the Florists' Club of Washington, D.C., February 5, 1907.

Having been requested several times by Secretary McCauley and President Bisset to give some of my experience in hybridizing, I do it with reluctance, as I find the longer I study and work in this line of business, the more I find there is in the mysterious working of nature. Hybridizing has been carried on by botanists for nearly 200 years, but more for scientific knowledge than for the improvement of florists' flowers in particular.

The first hybrid tea roses were raised by Mr. Bennet of England and these were rapidly followed up by the products of German and French rose growers. The first hybrid tea rose in this country, Souvenir of Wootton, was raised by the writer of this article about 20 years ago. It was the outcome of crossing Bon Silene with Louis Van Houtte. In attempting to recross this rose for several years I found it had a tendency to reproduce itself and I abandoned it.

Then came Marion Dingee, out of Caserte, a good, dark red rose for outdoor purposes and Mrs. Robert Garrett, out of Sombreuil, by Caroline Testout. Thousands of seedlings have been raised; some of them have produced extra fine flowers, but the habit in the way of growth, and the production of the flowers for commercial purpose, was such that it would not pay to grow them. I found that by recrossing some of those seedlings which have the least faults, we were more likely to get good roses for commercial purposes. I have one now which has good points for commercial winter work. It is the second generation of my white seedling, Madonna, and Enchanter. It has a stronger growth than either of them, stiff stem and large pink flowers, a shade lighter than Enchanter. Another one, which is the result of crossing two of my unnamed seedlings and had American Beauty blood on the male side, is now 10 months old from seed, and has produced this winter five beautiful, shell-pink flowers. These are as large as those of American Beauty, with three and four feet of stiff stems and foliage larger and handsomer than that of that famous rose. Only the future will tell how satisfactory this is going to prove.

There are many other recrossed seedlings in sight, of which I will not speak now; the trouble with most of our winter flowering standard varieties, such as Bride, Bridesmaid and Golden Gate, is that the organs are in 99 eases out of 100 imperfect.

The very best in pink is Caroline Testout. In red we have good material to work on, such as Richmond, Cardinal and Liberty.

Marie Van Houtte, with its strong, healthy growth, makes a good seed bearer, also Etoile de France. As this proved to be too double I thought of using the pollen for a less double rose. I used Richmond; the result was that two seedlings came up and bloomed for the first time a month ago. One of them was perfectly single, with a more rapid growth than Richmond, and the other one as double as Etoile de France.

I have several seedlings, where the pollen was taken from three and four different varieties mixed together, and they are the richest color in red of any I have ever raised.

In most cases, if a white variety is crossed with a pink one, the produce will be lighter than the parent pink, and if you cross a pink rose with a red one, it will be darker. For the seed bearer I would use the strongest grower and for the pollen bearer, the best color. It takes four or five months for the seed to ripen. When perfectly ripe, bruise the heps, or seed balls, and put them in sand. They will soon rot, when you can wash the seed out and sow it at once. It will take from three to ten months for any to come up.

You will find that not near as many will come up as you have sown. The reason of this is that a great many of the pistils are crooked and twisted, consequently the pollen can't be carried down to the ovula. I always take a little pollen of the seed bearer in order to get as much of its habit as possible, as the pollen parent sometimes dominates over the seed bearer and you lose exactly what you have been trying to preserve, a strong growing habit. Under glass I fertilize any time, summer or winter, outdoors in summer. This has to be done early, as the pollen on a hot day towards noon gets hard and is worthless. If the pistils on the surface have a watery appearance, then is the time to apply the pollen. If the flower which you wish to fertilize is not quite ready to receive the pollen, you can cut the flower you wish to pollenize with, put it in a tumbler of water in a cool, shady place and it will keep for two or three days.

Mardner of Germany was the first to give the florist some real good things in the way of azaleas. The first crossing of tuberous-rooted begonias was made by Zeith & Sons of London in 1869. Much has been written lately about the hybridization of the pear. My first attempt was about 15 years ago. I crossed the Duchess with the Seckel, and the Keifer with the Seckel, carefully pollenizing them for two days in succession. As the flowers appear in clusters, I pollenized every one on one cluster; in a few days after I examined them and found that half of them were dropping off. I had noticed at the beginning that some of the stems that carried the flowers were of a much paler green than others. By close examination and dissecting I found it was the fault of the stem that supplies the flower with nourishment, and no amount of pollen would set any fruit. This shows that the fault of not setting fruit is put on the wrong side. Plants are capable of forming the fleshy part, or the shell that surrounds the germ or seed without any pollen. We have seedless apples and pears, provided the organs joining the stem are perfect and feeds them.

I have a Cycas revoluta which every other year brings a crop of seed, but the fleshy part and the shell that surrounds the little bulb inside is always perfect. All it would need would be pollen to fertilize it, as pollen is nothing more than living cells, and with these cells life begins. My advice to young men is, begin early and study plant anatomy and physiology. Dissect the flowers and fruit, follow up the organs, see where they start from and where they go to. Without this study you will be working in a fog, but by studying them you will be able to gather a few pebbles on the shore of horticultural knowledge.

Cook: Rose Breeding (1905)

Cook: Rose Breeding (1906)

Cook: Rose Breeding (1915)