Is this a fungus? Still trying to find out what the plant is, but this yellowing is only happening to this one plant in the bed. I have another one of these, a rose and some small hostas I just planted and if it is a fungus, I don't want it to infect my others. Any clues? ( photo / image / picture from dmouse's Garden )
If it's on only one side of the plant I wouldn't think "fungus" first, but more like wind scorch, sun scorch, or "passing dog or cat spraying".
I thought that at first too, but no strays in the neighborhood and my dog can't reach it. Plus, it's spreading upwards. The leaves on the top right were green last week. That area only gets late evening sun through the tress - it's in full shade most of the day. I just read about something called verticillium wilt and was thinking maybe that? The leaves will fade, turn yellow, then wilt and turn brown. Only solution to that, at least from what I read said to destroy the infected plant so it doesn't spread...
I'm going to try and trim off the bad first and see if that stops it. What I read said to see if there a dark streaks in the stems - if there is, that's what it is... I'd rather lose that then my rose...
Have to laugh at myself! Think I figured it out. There is a small sidewalk that borders this bed. It has some big cracks that the dandelions love to fill in. We cut them down and sprayed some round up. One of the cracks lines right up to the side of the plant that was wilting! Cut off all the dead leaves, and put a little 3 month fertilizer to help give it some strength. Will wait and see what happens now.
To each there own but the very words "Round up" make me shiver .. My first house years ago was a semi. I spent years working the front into a green oasis. A new owner moved in next door. Never took care of his place and one day sprayed round up all over his front beds. The over spray killed half my plants ... They have banned "round up" here. (we exceptions)
Not something I like to use either, hubby and son have asthma and the smell can sometimes trigger an attack. The sidewalk is one of the few places I will though because the roots to the weeds go deep and I have neuropathy in my hands, making it very difficult for me to dig in the narrow spaces...
I think your plant might be a delphinium I had to laugh at your round-up experience because we did the same thing I had this one little old iris that looked weird. It was kind of gnarled up and twisted. After several photos and on-line conversations with an iris grower we figured it was "round-up poisoning" It is coming out of it, slowly.
Flowers finally bloomed, and it's monkshood... but, the other side is turning yellow now and the second plant started to as well. Will have to keep watching it... Thanks all!
Does look like a delphinium. It doesn't look like herbicide damage, and Round up isn't taken up into the roots. I used to grow these commercially and they can be tricky. Very often they can get fungal pathogens because they are too wet in the colder seasons. To me that looks like either drought or possibly a fertiliser deficiency. Wouldn't rule out verticillium either, but I thought you tended to get black leaves rather than yellow. The best thing is to remove the affected foliage, spray with a fungicide and fertilise (as you have done). Hope they perk up!