I have a couple roses that act in a similar fashion. I've always assumed that the water/rain causes botrytis--which I guess is a fungus (someone correct me if I'm wrong). At any rate, because I like my two roses that have this problem, I take the trouble to help the blooms open before they "rot" on the stem. It is the outer petals that stop the bud from fully opening. Place your thumbs on either side of the bud and gently pull down on the outer petals (repeat as needed). Usually the bud will pop open and bloom normally.

But, hey, there are hundreds of other roses out there that don't have that problem, so if you don't have a strong desire to "save" your problem rose, find another that is less temperamental.

Kate

I agree with Kate that botrytis fungus is the likely culprit.

It will make life easier if you stick to rose varieties that do well in your climate.

Prairie -- I live near the SoCal coast, in the "Fog Belt," so roses which CAN be troubled by damp ARE troubled by damp, here.
We find that roses with thin petals and a very high petal count are most likely to be affected by rain or general damp, so we try to stick to cultivars whose blooms have 25 or fewer petals, and whose petals have some substance to them.

In some cases, if the weather clears after a damp patch, blooms will open normally after we remove the damaged outer ("guard") petals.

Jeri

Thank you! OK, good to know what it is, how to help the buds, and that different varieties show different sensitivities.

petaloid, the whole reason for this variety is that it IS supposed to do well in our climate! I am learning, however, that of the ones that are supposed to do well here - some do better than others (of course).

jerijen, thank you for the info about types of blooms that resist rain.

Kate and Jeri - I will try removing the outer petals next time we have rain when they are in bud (which is supposed to be tomorrow...).

Thanks all! You may have saved these Fireglows (at least temporarily).

Yes, too often when a rose variety is said to do well in a particular climate the writer is just referring to cold-hardiness, or perhaps blackspot resistance.

Everyone's growing conditions are unique to their micro-climate, so we have to try out varieties that may be suitable and then decide what to keep.

Best of luck with your Fireglows!

Do any of you find that rain can destroy the buds of roses so that they never really open?

HEAVENS YES!

That was why I got rid of the Bourbon rose Madame Pierre Oger (an otherwise lovely rose in its demure way). It's hardy enough to (mostly) survive my winters with little trouble, but my summer (especially the June flush time) is most often cool & humid/damp, sufficiently so that her flowers rot sooner than they open.

It simply didn't work for me, especially since she is also very susceptible to blackspot. Ultimately a harsh winter did her in, and I didn't replace her.

Finally! All my roses have this very frustrating condition for the last two years, I thought it was thrips! What is the remedy, fungicide? Any particular kind? Other than pulling down petals for each bud by hand, any organic controls? I think I do also have thrips, by the way,how best to get rid of them?

There are a lot of roses that "ball" (never open) in wet weather. That doesn't necessarily mean they have botrytis (yes, it is a fungal disease). Like Jeri said, the number of petals and the petal substance plays a major roll. I live on the Great Lakes and Humidity is our middle name so I get a lot of balling too. I got rid of JFK because only one in ten buds ever opened. (The buds are lovely but really, I want them to open!) The white roses seem to be the worst for this. Maybe because their petals tend to be thinner. Pope John Paul II opens fairly well but even it can ball in really wet weather. Hopefully, WHEN (not if) things dry out your roses will go back to their normal beautiful selves.

Also have a lot of trouble with Botrytis in SW Florida here so the "cool" wet weather isn't necessary to get Botrytis, as the lows are generally still over 80 degrees in these summer months.

There may be some confusion between flower thrips and botrytis. Look between the petals for tiny scurrying insects, using a hand lens if you don't have good vision.

Thrips damage is often worst on the petal edges; main petal surface looks scratched; buds of some varieties can stick together and become puffy; but especially, you see lots of thrips in the flower.

Botrytis does flourish with cool temperatures and rain; gray mold is sometimes visible; some varieties develop pink/red spots on petals; with very severe infections, the bud turns to peanut butter and then dries crispy in the sun. Mild infections produce damp brown spots on petals which dry crispy.

Great explanations of the differences between the two, Micheal. They do have similar symptoms at first glance but there are those distinct differences that you've described. The pink spots are a dead give away on the paler colors but on the dark ones it's much hard to tell.

@pppp:

There is a similar petal blight caused by Alternaria fungus which might be active in warm weather in Florida.

I live on the East coast in zone 7 and have a Double Knock Out Rose bush. It is probably around 10 years old now. Still have the ID thingy that came with it. Says "Full sun, zones 5-11, and blooms spring to frost". It definitely gets full sun. It is always so pretty when all the roses open until we get a heavy rain!! It damages all roses, even fully opened roses. I ended up trimming my rose bush back to about 2 1/2 feet last week. Trimmed it like it should be trimmed in the winter. I hope l didn't kill it. Looking at all of those damaged roses is so disappointing!!! The leaves didn't look healthy either. They had small holes in them. Is something eating them? They are so much trouble to keep up. Thanks.

Probably rose slugs eating your leaves...Little green worms can be mostly found on the underside of leaves...

In the Spring when you first start seeing holes or white marks on the leaves is the time to take action either my locating the rose slugs and picking them off the bush or by spraying... Least toxic spray would be safers insect killing soap or spinosad always follow directions....