What Is This?

I noticed this on several of my 3K20 seedlings and only on them. If it’s black spot, it’s usually early for here. These are planted fairly close to some raspberries. Could this be from them?

Could it be frost damage? We had a late freeze on Mother’s Day. I noticed similar damage on a few of my yearlings, but more along the edges.

Looks a bit like sunburn to me.

Were they just moved to this location to was some shade removed? Exposure changed somehow?

Water on the leaves can focus the suns rays on the tissues.

I would guess fungal. Spot Anthracnose is a possibility. See link:

Link: www.ppdl.purdue.edu/ppdl/weeklypics/6-14-04.html

No, they have been in this location since the fall of 2008. I mowed some tall grass around them just this weekend though. Another plant has it just as bad or worse and it’s 30’ away, so I don’t think that’s the cause.

I thought fungal at first also, and Spot Anthracnose is a problem here, but usually later in the season. When the plants have had it before, the spots were smaller and more of them, as if they were shot with a shotgun, just like it shows in the link. Of course it varies from plant to plant. These plants should be pretty healthy though, they have survived several cullings for disease now, but I was concerned it was something new.

The more I think about it, the more I’m leaning to frost damage, it got down to 28F on Mothers day. I noticed that the leaves on numerous plants were wilting after that. And it’s pretty wide spread, it’s not just in one area.

Could be Downy Mildew…usually there is some purple discoloration but in different plants it can appear differently.

Paul, I really think you are right to think that the freeze may have contributed to this damage…the truth is however I have never lived in such conditions to have observed this first hand, so I am guessing FWIW. I hope that was the last of such abruptly cold weather for you.

The more I look the more I

Paul,

Has there been cane damage on your plants? You will usually see some cane damage accompanying frost damage such as purple lesions at leaf nodes that have been damaged or even blackening of some canes or parts of canes. After the early start to our spring this year, the recent stretch of snow and freezing temps have forced me to go back and prune out damage to some of my roses several times. It is frustrating that roses that survived the winter are now suffering severe damage from wild temperature swings (I much prefer the abnormal 80F temps we are currently experiencing to snow)!I think that the damage on your foliage could be due to the frost on Mother’s Day that was accompanied by a rapid rise in temperature that day. The melting frost may have acted like a sort of magnifying glass for the sun and fast rising temperature. I think Robert was right–it is a sort of sunburn to foliage with frost.

Julie

Julie,

I haven’t looked closely enough to the plants to notice if it’s on the stems also. When I get home from work I’ll take a look. Luckily I only had one night of freezing temps and not two nights and snow like you did so most of my plants came though unscathed. And most the one’s that do have some damage seem to be doing fine. I’ll have to keep an eye on the ones that were hit the hardest. I’m just thankfull I hadn’t planted out my seedlings yet. I made that mistake the last two years and it took 6 weeks for them to come back after the freeze. I hope your plants bounce back and you’re able to do some hybridizing with them this year.

Paul

I looked when I got home and there was very little damage on the stems. There were a couple spots that looked a little lighter, shading towards tan, but that’s all I could see. I don’t know if that is a good thing or a bad thing.

I’ve been hit with frost several times in addition to the snow over Mother’s Day weekend. I think you can get through a light frost with no problems, but when you get into the twenties you start to see more serious damage. I’ll keep my fingers crossed that you escaped with little or no damage.