RHA Newsletter 12(1): 17 (Spring 1981)
SOME DISAGREEMENTS
    (1) Discarding floaters
    (2) Hold-over Seed Flats
    (3) Petal Increase
  by George Mander,
Coquitlam, B.C.
Canada

In December, 1980 Newsletter (Vol. II, 4), page 10, Anthony Perry's article "Rose Seed”, there are two statements with which I do not agree. He says the "shelled seeds are put into plain water and all floating seeds discarded as being hollow. It does not pay to plant floaters," Wilhelm Kordes once advised me that some floaters will germinate. I keep all my, floaters and if I have a large percentage of a certain cross I will plant them separately and very close together (1/4"). I have found that about one seed in 10 to 20 floaters will germinate.

Mr. Perry also writes "it does not pay to hold seeds over for another year." I strongly disagree with this. Here are three examples from my own experience: 'Mount Shasta' X Rosa foetida bicolor ('Austrian Copper'), of a total of 9 seeds, only 1 germinated in the first year. Six more came up in the second year. (Please note that the pollen parent is yellow). From one of my own seedlings X 'Over The Rainbow' (Miniature red & yellow bicolor), of a total of 10 seeds, none came up in the first, but two have germinated in the second year. Also, of my most interesting crosses with R. nutkana pollen in 1979, I have just had my biggest surprise; I had 430 seeds from the cross (seedling of 'Parkdirektor Riggers' X R. nutkana) of which from January to June 1980 only 5 had germinated, and I gave up all hope of getting any more because of nutkana's  chromosome count of 42. However, after another cold period outside (28.45 degrees fahrenheit) for about 7 weeks in November/December 1980, another 47 have just germinated from Christmas to January 10, 1981. All these results prove that it surely paid off for me to hold the seeds over a second year. In the last four weeks approximately 100 more seedlings have germinated from my 1979 crop of 1500 seeds.

In his book "Roses", Wilhelm Kordes advises not to discard floaters, and he also says that some varieties of roses, especially those of yellow parents, have seeds which may not germinate until the second spring. I have Mr. Kordes' book in the German edition, and have always taken his advice in all aspects of rose breeding. In 1971, during a trip to Germany I had the pleasure to visit Mr Kordes at his home and we had a lengthy talk about roses and hybridizing. May I suggest a reprint of Mr. Kordes' chapter on hybridizing again would be of value to many RHA members.

Also in the Winter 1980 newsletter, Dale Meinzinger's article "Beginner's Germination Method" has two statements where I disagree with him. He writes: "those that float ...discard these". Also of petal count: "whatever the number of petals in the first bloom, that is all you will get in the future." I completely disagree.

I had petal numbers increase from the seedling's very first bloom to its second and third bloom, and also in the seedling's second year, but did not keep any records of it. By budding the tiny seedling's eyes after its second bloom onto an understock, it surely gave me a big increase in petals. Here is my record over the past 10 years, after budding a few hundred seedlings onto multiflora understock: the lot number is the very first bloom, the 2nd number, after budding.

5 petals stayed single
7 petals increased to 10/15
10   " "      "  15/20
15   " "      "  20/25
20   " "      "  30/35
25   " "      "  35/40
30   " "      "  45/50
35   " "      "  60/70

A few seedlings' first blooms of 45/50 or even 70 petals at one time, increased to between 70 and 100 petals, but never opened outside.

Here is my method of holding seeds over. In the last 3 years, I have kept all trays over for a second year, regardless of what percentage have germinated the first spring. From June to October I let the trays dry out completely. In November/December I give the seeds their second cold period of approximately 6 to 8 weeks. I soak the trays well and keep them in a refrigerator or outside in temperatures from 30 to 45 degrees F. Then after approximately 1-2 weeks some will start germinating.