I have never seen actual bud drop (drying, withering, grasshoppers, etc, yes,) due possibly to pollination of blooms, but this is just for no perceptible reason other than just that. I have a one yr old cross of Moondance x Prosperity that is suddenly dropping all its’ small buds as I pollinate one or two flowers on each stem. I want to see what it does because it has produced so many flowers, about 2 1/2"-3" across, is very vigorous and has great health. Could it just be that it may not be mature enough to ‘handle’ blooming and producing hips? or do some roses just do that, like a peach tree that sets to much fruit and has to be thinned? It seems healthy and not underwatered, although it is in a two gal pot. I have attached a photo from about 10 days ago. It is right now shooting up new canes with more buds on them that look healthy. Or does extremes of temperature fluctuation cause bud drop? We have certainly had a lot of that.
[attachment 1643 2012MndncxProsperity194.jpg]
I get something similar from Brigadoon and Double Delight, they start to set hips and then abort. Reine Des Violeties does set hips but without seeds.
Your talking about new flower buds on the plant that have not opened yet right? If you are I have seen it but the times I see it are on plants that suddenly go from cool weather to really warm and I have also seen really young seedlings and cutting drop buds with me barely touching them for no apparent reason without any pollination involved. So far in my experience it seems young plant don’t usually hold hips long after fertilization but I have not seen other flower buds just fall off due to other flowers being pollinized. I however do not grow any of the varieties in question. If this does happen it would not surprise me one bit it seems fairly common in the plant world for plants to generate more flowers than they could possibly carry to seed.
Yes, this is the new, nonpollinated buds that are yet to open that are dropping, but in the same sprays as the newly pollinated ones. We have been having epic hot/cold/damp/dry 3-5 days spells that see an approx. 40-50 degree temp. and humidity swing in one day, sometimes for 3-4 days in a row. Like today again. Did not even give that a thought but those are not the usual temps we have here, and in my experience Prosperity does not like at least the hot end of those swings, and it is one of the later ones to get started in spring, so maybe this is an inherited thing? It has been my experience that if a plant is a bit stressed what it does is produce smaller and smaller blooms with less petals and then just stop blooming until conditions improve. Conditions have been overall good which is why I thought the pollinated hips may have been the cause.
This year, I had a surprising number of buds on seedlings abort. I finally realized that it is because I switched to Pro-Mix which has zero added nutrients whereas I had used Redi-Earth which was intended for seeds and has starter nutrients. But among mature roses, the Lesser Maiden’s Blush is one that always does that abundantly and excessively. Some years are worse that others. But it seems to put up way too many buds for its energy stores and anywhere from half to 3/4 turn yellow and drop off before opening. It blooms fairly late when it is usually getting hot here, so there may be stress effects too. New Dawn, even later, does not do that. Thus it must be a genetic trait somehow.