How are florist roses 'denatured', or rendered sterile?

Whenever I cop a few rose blossoms from a funeral or wedding bouquet with the idea of using the pollen from them they never dehisce. Often the anthers just turn rubbery, and grinding the dried anthers doesn’t release any usable pollen either.

Does anyone know what the greenhouse growers do to them that prevents pollen from releasing?

I have used florist originated pollen just once, taken from a birthday bouquet, and the flowers were purchased from Costco, but they released their pollen (I had more than I could use, and I used more than I intended) without a problem. I wonder if the flowers being stored for much longer times in a refrigerator (Costco stores them minimally, and then they are displayed at room temps.) would have anything to do with the pollen going useless?

I always assumed a lot of it had to do with going back and forth from humid to non humid environments and other treatment that is not ideal for the rose. Also I think just like fruit and vegetables the flowers are picked too early and ripen in cold storage or something like that. But these are just therories. My experience of cutflowers starts at the warehouse, store and at home; before they get to the warehouse I can not say what they do to them. But at least in the warehouse and stores they are usually not treated very well. I have had the same experience as you have Don with pollen from cut flowers. Only occasionally am I able to get any usable pollen from them. For me it is more of a shock than a norm.

Hi Don,

I think that Jackie and Adam are right. Some of the cut flowers are cut very early and the blooms open very slowly such that the pollen is “old” by the time we get the blooms. However, with fresh cut flowers that really look good, the pollen has often been very viable. If you keep looking, you should find some cut flowers that produce good pollen.

Ive had mixed conclusions re" florist pollen. However, Ive never had any good germinations with any pollen that was useful, so I gave up caring.

I suspect some of the challenge getting pollen out of anthers of some of these roses is variety related in addition to environmental. A few years back I was able to go to a regional greenhouse (one of the few left for us in the upper Midwest) and collect pollen. Smaller stems that aren’t harvested had further along blooms I could collect anthers of at the typical stage. Many did not release much pollen. It seems too that some have very small or underdeveloped recepticle tissue too that may make them challenging to use as females too. Anyways, some like ‘Orlando’ produced pollen that produced seeds. Unfortunately, in the end I didn’t have any seedlings that I kept. They were kind of weak with the crosses with my hardier shrub roses and disease prone. If some were more vigorous I would have saved some. Maybe it was the varieties and female parent combinations that didn’t work well and I shouldn’t give up. Frank B. sure made great advances for miniatures that are basically dwarf hybrid tea cut flower type roses using cut rose cultivars with minis. I’ve been thinking, at least for me, that there are enough garden roses (nicer more compact plant habit and good growth in the typical garden) with great floral qualities that it may be better for me to pair them with the hardier shrub selections I have to move forward. I did have fun walking through their greenhouses collecting pollen and ooing and ahhing over the cut flower roses. It would be fun to do again just to see their more recent varieties they’ve added.

Back in 2008, when I was writing an article on color for the RHA Newsletter, I had some correspondence with Keith Zary who told me that Suntory actively denatured their genetically engineered cut roses to as a measure to protect their intellectual property. Hence, I suspect that other corporate breeder-producers do the same especially because of the particular rubbery quality of the anthers that I mentioned.

While it’s interesting seeing the advances, or even just changes, in florist types, extremely few make worthy garden plants. Why should they? Nothing they are expected to endure remotely resembles what they are going to be subjected to in the majority of garden environments. Unless you’re simply aiming for novelty, I don’t consider any florist type worth mining for anything. Too many undesirable traits come with the flower form, stem length, repeat cycle and colors. That’s fine if it’s a cut flower type you’re attempting to create, but I personally don’t feel any advances in health are likely to come from that direction.

flower form, stem length, repeat cycle and colors.

Also, mildew resistance, petal count, petal size, petal substance, pigment density and thornlessness. Colors are potential tartget traits, too, although it is impossible to know whether some of the hues we see at the florist are from dye. There’s only one way to know for sure. The major downside is, as you say, that they require environmental coddling.

Here’s a different perspective that might help you understand why I want to have florist roses in my gene pool.

I’m trying to create a few worthwhile breeders starting from species roses that include acicularis, chinensis spontanea, wichuraiana, glutinosa, roxburghii, omeniensis, ussuriensis, hugonis, praleucens, moyesii, virginiana, glauca, woodsii and spinosissima. I’m also working with close hybrids of bracteata, pisocarpa, fedtschenkoana, rugosa, nutkana and foetida.

These are the opposite of being refined. You could easily say that each of these species or close species has too many undesirable traits to be worth the effort of taming them.

I was more interested in the extremely unusual colors, such as that of Coffee Country.

I had some correspondence with Keith Zary who told me that Suntory actively denatured their genetically engineered cut roses to as a measure to protect their intellectual property.



If you ever find out more from Keith Z about what exactly he meant by “denaturation” methods, please inform us!!

Although I am not for one minute doubting all the collective ideas and advice here, the kid in me remains curious about this…can’t help but think about sci-fi stuff like gamma ray guns directed at their GM-flowers etc…