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Journal American Rhododendron Society

Current Editor:
Dr. Glen Jamieson ars.editor@gmail.com


Volume 32, Number 1
Winter 1978

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Notes and Suggestions on Making Crosses
Bill Moynier, Los Angeles, California
Reprinted from the Newsletter of the Southern California Chapter

        Everyone in the chapter should get in on the fun of creating some new hybrids. Even one cross will supply enough seedlings to inundate an average backyard. If you plan to try your hand at hybridizing this spring, the following suggestions may be of help. This is how I go about it. Undoubtedly there are better and more sophisticated procedures to follow, but I commend this technique for those who would rather lean to the lazy man's approach.
        It is best to de-petal the female parent flower just before it opens. This results in an almost zero probability that an insect will make the cross (even though some such crosses have turned out to be the very best ones) before you do.
        Wait several days until the end of the style becomes sticky, then apply the pollen. (In looking at some four and five-year seedlings from some of my earliest crosses, when perhaps I did not want to spoil my only truss on a plant and, therefore, didn't de-petal, I find that almost without exception, these turned out to be the crosses I intended. From my experience, then, not de-petaling is okay - but de-petaling is still safer.)
        Size 000 gelatin capsules, available at many drugstores, seem optimum to me for storing pollen. They are large enough to write the name of the pollen parent on the outside with a felt pen. Freshly picked pollen may be used immediately. If it is to be stored for any length of time, then the capsule is placed in the refrigerator for several days to dry it, then placed in a container with some desiccant (use cotton between the desiccant and capsules) and stored in the freezer. The capsule can be taken out and used as many times as you want; pollen should remain viable for at least two years. Most pollen drains from the anthers while in the gelatin capsule and forms globules of pollen which stick to the inside of the capsule. The use of a toothpick to dip into the capsule to get the necessary pollen for a cross was recommended by Cecil Smith of the Portland chapter and I have found it a most helpful piece of advice.
        You can label your own crosses with many types of tags. My favorite consists of a quarter of a ¾-Inch by 3-inch aluminum label (sold at most nurseries) using a piece of small gauge flower arranger's wire about 6-inches long to secure it. The wire is available at most dime stores. The ability to simply twist the wire to secure it is a significant advantage, in my opinion, over string which must be tied.
        If fertilization is successful, swelling of the seed capsule should be apparent within four to eight weeks. Start watching the capsules beginning about September and harvest as soon as splitting at the end starts. Even if they have not started splitting, I normally harvest all seed capsules by mid October. I use 1½ x 2½ small brown envelopes (available at stationery stores) to put the seed capsules in. To expedite splitting of the capsules, I hang the envelopes for three or four days on the wall inside the cubbyhole in which the hot water heater stands. Those capsules which have not been induced to split in this time I attack with small scissors and do it the hard way.
        Since I do not try to carry over seed for a second year, I simply store the bare seeds in these same envelopes in a small box in the house. I prefer planting the seed as soon after harvesting as convenient to get as early a start as possible, but waiting until spring with its warmer, more growth-inducing temperatures certainly is okay, too.


Volume 32, Number 1
Winter 1978

DLA Ejournal Home | QBARS Home | Table of Contents for this issue | Search JARS and other ejournals