How Many Roses?

Roses for Hybridizing
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Okay, here is a question to generate different opinions:

How many rose seedlings do you have to grow to find a good one?

Depending on the cross, I have estimated about 1 seedling in a hundred is a good seedling, but to get a really good seedling, in my experience, it is closer to about 1 in a thousand.

How do you get that 1 in a thousand?

On average using good parents, I get about 80% take on my crosses. Then, per hip, I get on average about 10 seeds per hip. Then, considering germination, with a good seed parent, I get about a 50% germination rate overall.

So putting that altogether, to get 1,000 seedlings, I need to plant about 2000 seeds. To get 2000 seeds, I need to collect about 200 hips. To get 200 hips, I need to make about 250 crosses.

That is using the above example.

If I use a seed parent that only sets hips 25% of the time, yielding on average 5 seeds per hip and having a germination rate of 15%, I would need to make many more crosses and collect many more hips: It would take 6667 seeds, 1,333 hips and 5333 crosses.

The second example is not an uncommon finding when using a poorer seed parent. Lots of work to produce the same number of seedlings.

How many rose seedlings do you think it takes? How many seeds? How many crosses?

Jim

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For my seedlings as a whole, 1 decent seedling in 100, and 1 really good seedling in a 1000 is about right. The percentage of good seedlings is very dependent on the cross. I’ve had crosses that have had good hip set and produced many hundreds of seedlings, but not a single decent one. On the other hand, I’ve had crosses that produced few seedlings, but a relatively high percentage of those were keepers. I keep statistics to determine which crosses give me the most keepers for the amount of work required, and those are the crosses I’m most likely to repeat, even if they don’t have the best hip set or highest germination rate.

I use the statistics for my crosses between modern hybrids, where my goal is to get something good in the short term. When the cross has a longer term goal, like bringing new genes into the gene pool, I tend to ignore the statistics.

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Hey guys - one might say all are good, some are better. I guess it all depends on what your goals are and then how picky you are in tossing those that don’t meet those standards. We generally have about 3-400 seeds and 100 or so seedlings, but after the first bloom we are way down to 25 or so and then down to about a half dozen going into the next season when we propagate some and get them outside into the test beds. Sure was tough the first few years to toss them out, but when you realize that you just keep them all it is a tad easier.

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I second Jim Turner’s remarks. I have some plants that produce hundreds of seeds of some crosses, but germination is low (15 to 20%) and a low percentage of them are worth keeping into the second year. I also have some plants that set seed only reluctantly, and which germinate poorly, but the percentage of “keepers” is about 50%! The way I see it is that even though some plants are hard to work with and the germination is poor, I will continue to work with them as long as they continue to produce nice plants. Ultimately I judge the results by the number of plants I save for evaluation, not by sheer volume of offspring. Volume is worth considering, as long as I’m not throwing away 99.9% of all the seedlings; I just don’t have the capacity to deal with 3000 seedlings a year! (I estimate that I am sowing 30,000 seeds this coming Spring)

That being said, I also aim for the standard 100 seedlings per cross, if possible. To achieve that with some seed parents, I have to have multiple instances of those plants to accomplish that, Miniatures especially. (With the exception of ‘Sheri Anne’ which can produce thousands of seeds on a single mature plant!) Ralph Moore has told me on several occasions that in order to really see what a particular cross is capable of producing, that you must have at least 100 seedlings for evaluation. I consider this an ideal that I can’t always meet, no matter how I try. Some crosses simply won’t result in any more than 10% hip formation, and have poor germination to boot. But as I say, if that cross results in a dozen seedlings, from which I keep 6 or more, then it was well worth my effort! Case in point is a cross I did 2 years ago of ‘Rise ‘N’ Shine’ X ‘Gloire de Dijon’, which gave me about 10 hips, and 8 seedlings. I kept 4 of them, and one of them is a plant that is getting high scores from me. (see link)

I guess I would have to say that on average, one plant in 100 turns out to be decent.

PS: Is anyone working with any of the old Teas, like ‘Mons. Tillier’ and such?

Regards,

Paul

Link: www.rdrop.com/~paul/teas/rise_gloire.html

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Paul, I’ve been doing crosses with the Teas Mons. Tillier and Duchesse de Brabant for several years. I’ve crossed them with each other, with other diploids, and with a few modern tetraploids. Here is the first bloom on one of this year’s seedlings of the cross Mons. Tillier X Duchesse de Brabant:



Later blooms were even better. The flower is fragrant and the plant is very healthy.

Here is another seedling from the same cross:



This one is just as healthy as the other and has some fragrance, but is more floriferous.

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OK Jim, so using your first example of 250 crosses, (and I’m assuming that all crosses are using the same cultivar for the mother and the same cultivar for the pollen), then how many plants do you need to act as the seed parent? How many plants are needed to produce enough pollen?

Many thanks, Linda Sun

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A tad off topic but really gorgeous roses, Jim.

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Yes, thats lovely stuff, Jim! Thanks for that info.

Paul

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Jim, that is just superb, I’ve kept the pic because it is so beautiful.

I have never made no more than a dozen or so crosses of a single kind. Because I have limited space, and my seedlings grow in gallon pots, I just have to settle killing most of my seedlings.

Already I’ve disposed most of my Livin’ Easy x Rugelda seedlings. SO much mildew, but I was fair enough to save a few seedlings to evaluate them during the Spring. Now is very wet, moist and rainy, so they may do better then.

Enrique

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Once a plant breeder friend with a lot of experience told me that the outstanding vars were often found among unpromising progenies and resulted from improbable combinations. He added that in his opinion the poorer a progeny was the better were outstanding results odds.



With tetraploid roses different gene combination number from a single cross is by the millions. And allmost infinite when considering cross over and other somatic or meiosis hazards.

Number of rose seedlings needed to find a good one is according to the breeder skill and to how much selective he/she is.

Mallerin got a lot of successfull roses from his small garden when most commercial breeders raise an average of one or a very few marketable vars by 100,000 sown seeds.

Friendly Yours

Pierre Rutten

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Thanks for the nice comments on the Mons. Tillier seedlings!



Linda, I’m assuming that your question was for Jim S, so I’ll let him field it.

Paul, your ‘Rise ‘N’ Shine’ X ‘Gloire de Dijon’ seedling looks like a winner! Besides its obvious good attributes, it has the commercial advantage of filling an unoccupied market niche. Please let me know if you want to test it on the central California coast - a paradise for mildew and rust.

Pierre, another hybridizer who achieved great results with relatively few seedlings was Herb Swim (Mister Lincoln, Angel Face, Double Delight, etc.). He typically grew 10,000 to 12,000 seedlings a year, not very many for a professional hybridizer. During his peak years, he introduced 4 or 5 new seedlings a year. So he introduced about 1 seedling for every 3,000 that he grew.

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Hi Linda:

You can get 250 hips from a single excellent seed parent and since pollen can go quite far, one other rose is all that you need.

I am not suggesting to make that many seedlings (1,000) from a single cross, however. I agree with Jim Turner and Paul that 100 seedlings from a cross will give you a good idea about a cross. Though I must say also, that if you find that a particular cross has produced some good seedlings, it is worthwhile repeating the cross extensively.

I have produced as many as 1,690 seeds from a single cross. That one (Chipmunk X Michel Cholet) produced two good exhibition minis for me, ‘Sam Trivitt’ and ‘This is the Day’. This year I repeated a cross of (Chipmunk X [(Lynn Anderson X Tournament of Roses) X Hot Tamale])crossed with [(Singin’ in the Rain X Roller Coaster) X Tropical Twist] to produce 1447 seeds. I am hopeful to get something good out of that cross also.

Jim, I still tend to especially use excellent seed parents when trying to fix a long-term goal. I started working with the Hulthemias and tried to stick with excellent seed parents so that I could maybe get the gene that I am looking for in a more fertile seedling. At that point, I can then work on other things, like cleanliness, bush and flower-type.

Paul, I agree that it is often worthwhile to do some crosses that you know won’t produce much, but you know that the quality is there. Still, one of my efforts is to again take the excellent seed parent and use it with the two more difficult varieties that you are using. Then selecting better seed parents from resulting seedlings and then crossing those with each other.

Selecting excellent seed parents among my seedlings has been a very useful strategy for me.

Jim

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test post

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Hey Jim, do you have a time machine??? I just noticed that the date on your post is “Wed, Apr 18, 1973”! LOL! The messages are sorted by last update date, so this topic went to the bottom of the list after your post instead of the top. The date comes from the web server, so maybe there was something wrong with its clock at the time of your post. Please let me know if you see any other anomalies.

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Hi Jim:

Thanks for figuring out the problem. At least my server got the day of the week and the “18th” right!

Hopefully this post won’t mess things up again.

As I said in the last post, electing excellent seed parents among my seedlings has been a very useful strategy for me.

That is true even when the selected seedling seed parent is not that spectacular itself. I have a seedling that sets hips wonderfully, with good germination, but is not itself very attractive. It does have some good qualities - nice foliage, and a nice informally shape bloom, but the color is a plain white and the petals will not fall, so the plant can look pretty ugly. Anyway, as a parent, I have been happy with it. I have two seedlings from it this year that are much more attractive than their mom. I put one in the page link and one in the photo link. They are another example of how different offspring from the same parents can be.

Jim

Link: home.earthlink.net/~rosesbydesign/LDYGExSeedlinga.htm

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Here’s the other seedling.

Link: home.earthlink.net/~rosesbydesign/LDYGExSeelingb.htm

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Jim, just out of curiousity with your pink seedling–does it have the same red stamens that Geisha has? Geisha has always had the most dynamic looking open bloom in my opinion. I think Im off topic again but it’s exciting none the less =)

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To either Jim,

Obviously I am doing something wrong or just don’t understand. Let’s go back to the issue of 200 hips from 250 crosses. I can only begin on a Saturday in April plucking petals from a Tiffany and bringing the flower from New Zealand indoors to prepare for pollen. Then on Sunday I can do the cross. Next weekend I can do this all over again (if both plants have blooms in the right stage). Unfortunately the roses bloom on their own schedule, not on mine, so what happens is that I may get 4 or 5 crosses per season (per seed parent)and 3 or 4 hips, not 200 hips. Even if I did not work full time I doubt that I would have 250 blooms on a Tiffany and 250 on a NZ in the correct stage of opening to cross fertilize in the Spring. I realized that I would need more plants, so now I have 3 Tiffany and 3 New Zealand and have begun doubling up or tripling up on my other roses. Are you telling me that all I need is one plant of each parent? Sorry for the confusion, but thanks for the help. LInda Sun

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Hi Jadae:

The pink (LDYGExSeedling) seedling has the form of it’s mother. Geisha was the grandmother. Although I have other Geisha seedlings that have the attractive open bloom anthers, this one does not.

Hi Linda, I am sorry that my previous answer was confusing. What I meant, was that with a good seed parent (Tiffany is not a good seed parent - although you might get some seed set), you can get by with one or two plants and still get 250 hips. I have 2 Lynn Anderson bushes and last year, harvested 333 hips from the 2 plants, but easily could have gotten more had that been my only focus.

In my experience, New Zealand is a better seed parent than Tiffany, so I would try your cross in the other direction. If you have Lynn Anderson, you might try New Zealand pollen on it and still get fragrant seedlings. I have a new seedling with Lynn Anderson as the mom and New Zealand in the paternal grandfather: Lynn Anderson X (Stainless Steel X New Zealand) that has fantastic fragrance. If you like fragrance, Stainless Steel has been a better seed parent for me than either Tiffany or New Zealand.

Also, I do all of my crosses in the early morning hours. Pollen is collected the day before and then applied to newly emasculated blooms the following morning.

I have another full-time job, but in April I get up between 4:30 and 5:00 am to start the rose breeding. You can get a lot of crosses done fairly quickly. It is fun imagining what you will get from the crosses.

Just be careful not to produce more seeds than you can handle!

Jim

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Thanks, Jim. Happy Holidays. LInda