I’ve found this year I’ve had a much greater seed set pollinating later in the bloom cycle than usually recommended. I’ve been waiting for the bloom to be almost fully open, but just before the stamens are showing. The removed stamens release their pollen very quickly in the jar and the stigmas seem much more receptive at that later stage. Of course, this varies with variety, but, at least here in the desert, it seems to work better. There’s always a risk of some self-pollination, of course. I’ve also been pollinating at night and covering the bloom with foil for 24-48 hours to increase the humidity.
How do you all do it?
I pollinate in 2 waves. Once in about 2 weeks (early June) and then about 2 or so weeks after that(mid to late June). This covers most of the roses. I have collected pollen already though.
Forgot to add: I dont do this when it is raining. Ive learned my lesson! It just doesnt work even with protection haha.
Actually, I should have clarified that. I meant in the individual bloom’s cycle rather than the plant bloom cycle. So, Jadae, you collect the pollen early, freeze it and pollinate later?
It depends on the rose. In general, I collect pollen in the morning of the day that I believe that the rose will open and pollinate in the afternoon or the following morning.
I pollinate whenever. Sometimes it gets so windy here, the only time I have is late at night.
I only pollinate blooms that would be opening that same day. I don’t try pollinating a bloom that is 2 days from opening. As you mentioned, it is a risk that the opening blooms can self pollinate before they are emasculated, but with practice, you can learn which varieties have to be emasculated first (before all of the others.)
I emasculate all of the blooms to be pollinated, first thing in the morning. After that, I go back to pollinate with pollen that was collected the day before. Finally, after all of that is done, I go back and collect pollen for use the next day.
I used to try to collect the pollen from blooms that I was emasculating (I still do this with roses having high potential for use as both seed and pollen parents, but only producing few blooms), but now I mostly just snap off a few blooms of varieties that I’ll want to use as pollen parents the next day and take them inside to remove the anthers in the cool indoors.
Jim Sproul
Judy,
It depends on the cultivar I am working with, but in general I emasculate and pollinate in the same day, using blooms that are close to open and soon to release their own pollen. Some things I work with must be emasculated a day before opening as they release pollen before the bloom is open. As I say, pollination follows immediately afterwards. I leave at least one row of petals on the bloom when I am done. An article I encountered last year vindicated my decision, stating that seed set was better on test varieties when some petals were left on the bloom after pollination.
With most cultivars I get near 100% seed set. Some experimental crosses inherently have low seed set or total failure, which is to be expected. However, the proven seed parents I use generally accept any and all pollen and result in hundreds or thousands of viable seeds.
Further, I do not fertilize my seed plants except once or maybe twice, after the seeds are already setting. I generally don’t prune my seed plants either, or prune very lightly. IE: less than 1/4 trimming. I never cover pollinated blooms either. My experience doing this gave me nothing but rotted hips!
Best wishes,
Paul
I agree with you Paul for our area but she lives in the desert and has complained before of hips frying and cracking. Some rose hips here just rot asap by breathing on them (I find that Tiffany is horrid for this) but Im wondering if this is different for different climates.
I always say everything is opposite here in the desert and part of that holds true for roses apparently as well.
I’ve gotten much better seed set this year than in past years but I’ve changed several of my methods so I’m not sure which changes made the biggest difference. My guess is covering the bloom (petals still attached) with foil for a few days after pollinating, in order to increase the humidity has been the biggest help. It has not resulted in hip rot here but seems to be helping me get a better seed set probably due to the increased humidity. Doing anything here in the desert is a unique challenge. Since we’re already up around 105 degrees this week, I would guess my pollination season is over, but this year I pollinated thru the middle of May. In past years I have not gotten seed set from May pollinations. In a few weeks, we’ll see if some of these late crosses took.
One interesting cross that looks like it may have taken is Color Magic x R. Acicularis Nipponensis. How wierd is that?
Another problem I’m encountering now that the heat is very high is anthers that won’t release their pollen. I wonder if that is temp/humidity related? That wasn’t happening in April, but now that it is very hot, the anthers have started doing this and I have to crush them to get pollen.
I guess a few humidity experiments are in order here. I realize it is always recommended that the pollen be kept dry, but I’m wondering if there’s such a thing as ‘too’ dry in order for the the anthers to release their pollen?
Like I said, everything is opposite here.
Judith,
Obviously my comments won’t help you at all! 
It is clearly a different game in your climate. Naturally, what works for me isn’t going to work as well for you. I wish I could offer more assistance, but my knowledge is limited to my own experiences. Best of luck!
Paul
Au contraire, Paul!!! The amount of knowledge I’ve gained from you and the others here is invaluable! It just has to be tweeked to fit a different climate.
Paul,
I am interested in your comments that you leave at least one row of petals on the emasculated bloom. From what I had heard, bees leave petal-free hips alone (eliminating the risk of pollen from another variety being introduced)–Has bee pollination caused you any trouble using this method?
Thank you–I too have gained much from your willingness to share what you have learned.
Rob
Rob,
I honestly believe that bees play an insignificant role in random pollination problems in my work. Its not that I can tell that in every instance the seedlings are obviously the offspring of the two intended parents, because I can’t say that for sure. However, I believe, as other hybridizers have told me from experience, that if you pollinate a bloom properly, applying plenty of pollen, that any stray pollen a bee may leave behind will have to compete with the thousands of grains I placed there. Frankly, I think that my work has the advantage of sheer volume over that of the bees (which in my greenhouses are few and far between anyway), and so I don’t worry about contamination. The thought of putting protective coverings over 7000+ pollinated blooms each year is an unwelcome one! One caveat to my process: plants that act as seed bearers outdoors will have the pollinated blooms covered for 24-48 hours after pollination during rainy spells.
Regards,
Paul
I looked at my sheet from last years pollinations in comparison to the time pollinated and germination ratio. Im not one to keep charts and stats (too much micromanagement for my preference)but the definite pattern was super lower germinations during the rainy period. Both sides of my chronologically numbered sheet has good to really good germinations as opposed to the mid sector was none to low. I always covered them up during rain btw.
Rain is, of course, not a problem here. It generally doesn’t rain at all in April, May or June. I told you everything was opposite here.
Judith, our climate in Bakersfield is probably closer to yours than to Paul’s, however, I follow nearly the same procedure that Paul does. I pollinate immediately after emasculation, do not cover the blooms and fertilize/prune seed parents only lightly. Leaving a row of petals on I have not done, but may try next year.
Your observation about pollen not releasing is something that I have noticed too. It seems that when the weather really heats up, that newly forming buds do not make much pollen. This is noticed even if we get a week of cooler weather following a hot spell - the new blooms that were former during the hot spell have little to no pollen. I have learned that it is almost a waste of time to continue with pollinations after there have been many days in the upper 90’s.
Jim Sproul
Jim, so you must have a short pollination season too?
The reason I cover the blooms is more to increase the humidity but also helps keep the heat off the pollen. I just looked up your weather and in terms of temps you are correct - not that much difference… about 7-10 degrees. Your humidity is quite different though at 42% today (yikes, that must be uncomfortable), while ours is 17%. I don’t know if this is typical for you, but almost no humidity is typical for us which I think makes pollen germination more difficult (but makes living here at 105 degrees livable). We’ve been in the mid-upper 90’s for quite a while now and I think (although this needs to be confirmed in a few weeks) that some of my crosses may have taken this year. I never had crosses take in May before. I’ll let you know.
Judith, good luck on your May crosses! Our temperature differences are just enough that I can usually get through May with breeding, but have very little luck in June.
We had only 75 degrees today - can you believe it?!
Jim Sproul
Oh 75! I can hardly remember it!