About two weeks ago, my bush (I think a boxwood) began dying back systematically, left to right! The dead sections are completely brown with no green left at all. The photo shows the underside of the leaf. I'm afraid whatever it is will soon destroy the entire bush.
Can anyone tell me what this is and how I might take care of it?
Any tips are greatly appreciated!
Here is a photo of the dead section.
Not a box; possibly Ilex crenata, but I'm not certain.
Certainly doesn't look happy! It has some sort of fungal disease. For starters, prune out everything that's dead/dying, well below the visible infection line. Disinfet the pruners between each cut, if making more than one cut.
Resin
Those black bumps/specks are sclerotia. Sclerotia are the overwintering structures for a fungus. Resin is absolutely on target to prune out the infected parts and disinfect the pruners. Consider also a squeaky clean fall clean up in the area under and arround the shrub. If there is mulch discard that in the trash. Increase air circulation around the plant if possible. It isn't always possible to get this under control. If you lose the battle remove the plant and send all infected material out with the trash. Don't replant anything susceptible in the same location. The fungus is soil born and once established can be the devil to handle. Even brushing up against a wet infected plant will transfer it to another. I lost a really nice tree peony to the same disease, despite all of the above efforts. Good luck!
Thanks for the quick responses! How should I best disinfect the pruners between cuts? Would a hydrogen peroxide/ water solution be enough - if so, what proportions?
Should I cut out the infected parts (which go all the way to the base of the bush) and then wait until fall to clean up the mulch in the area?
Also curious how I can find out what plants are susceptible in case I plant something else in the same location.
You might want to soak them in a bucket of 10% bleach for about 10 minutes. Sometimes I spray mine with Lysol.
Cut out everything you can get then bag it up now and toss it out with the garbage. Probably not a good idea to wait until fall to clean up the mulch in the area.
Select a few plants that you are interested in planting in the same location. Share your list here.
I'd not use bleach - it corrodes the metal on the blades, creating minute cavities which are nearly impossible to clean out. Best is probably isopropyl alcohol (skin-rubbing alcohol).
Resin
