Are you sure it's sap, and not moisture?

I would cut that off below the brown/black area.

Hi Jeri -- it's not moisture but something sticky and thick.

Sheila - I plan to cut off the affected canes. One of the roses, Princess Alexandra of Kent, has plenty to spare but Florence Bowers' Pink Tea, that Catspa on these forums was kind enough to give me, is still a small plant and all three of her canes are black and all near the base. I am prepared to cut but worry that whatever it is may spread. I can easily replace PAOK but FBPT is very precious.

thanks,

Jo

I've never seen anything like this. It sounds AWFUL.

I agree on cutting it. But I'd stop after the first cane, and get a good look at what's going on inside.

Thanks again, Jeri. I'll cut the cane on the Austin tomorrow and take a look.

Jo

Jo, I wish I could give you better advice, but this is way outside my experience. I'm thinking it would not be unreasonable to contact the Dept. of Agriculture??? Can't hurt to try.

I was thinking, too, that I should contact the Dept of Agriculture; they are nearby, so thanks for mentioning it. They were quite helpful when I was trying to figure out what happened to Mel's Heritage. And, that's what I am scared of - that I might lose FBPT, like I did Mel's Heritage.

Just got back from work; I don't see the black parts spreading. I will cut a cane soon and take a look at the inside like you suggested.

Jo

I cut the cane off PAoK. She's looking askew as the cane had a lot of vertical laterals, but better that than dead. The cane is black only on the side exposed to the sun; the underside looks normal. Here's a pic of the cross- section of the blackened part - the affected part is the right side. It looks clean to me. What do you think Jeri, others?

I have not cut any canes off of FBPT yet.

thanks,

Jo

The one-sidedness, as well as the singed color, looks like toasted cane to me, too. Carol

Agree with Carol -- the one-sidedness is telling. My 'Lilac Charm' (wimpy, scarce-leaved own-root plant-- at the head of the list for grafting, when I get around to learning that) got a burn like in your photos on the exposed side of a cane in the recent heat wave. And FBPT had a number of more exposed canes that significantly darkened, though not burnt (this is a giant, well-established, well-watered plant in the ground) on one side, too, from that heat wave (see photos below). The oozing sap may be due to phloem contents spilling from damaged cells.

Two-sided effect:

I think we've solved the mystery -- which means a solution is just over the horizon.

Thanks Jeri, Carol and Catspat. When I cut the cane and saw the burn only on one side, I put it down to very bad sunburn. I didn't cut any canes off FBPT; I moved her into the shade and have been heavily watering. Thanks for the pictures, Catspat.

We had one very hot day with temperatures reaching 97F. Reflected sunlight off west-facing windows hit PAoK and FBPT burning canes that were horizontal and not shaded by leaves. A combination of the high temp and reflected light did it. I have been putting a shade cloth over plants in the late afternoons although we are back to our normally cool summer weather, until I figure out a more permanent solution to the glare from the windows.

Catspat - FBPT is coming along very nicely! She has grown out of the pot I had moved her into last October, and she is now ready to go into the ground. I had planned to have her climb an arch, but after reading how vigorous she is, I will now plant her against the fence where she can fan out 15 - 20 feet in both directions. Thank you again for such a lovely rose.

Jo