I have a sick Rhododendron. The leaves are black and curly. Please see the attached photos. Does anyone have any recommendations about what I should do? Thanks!
you actually have an aucuba not a rhododendron. this damage is common in our area of the lower mainland and is most probably a bacterial infection due to the high humidity and warm weather we have during summers. I have seen this alot through the vancouver area. most people will just cut off the affected areas and let the plant heal naturally. remember to aleviate the stress the plant may be under. keep the plant well watered and try to avoid damaging the plants as you brush up against it. get a soil test to determine the nutrient load of the soil around it and feed to the reccomendations of the test
Thanks for the plant identification. I will stop calling my aucuba a rhododendrom. I will water it, and cut off the diseased parts. How does one go about testing soil? (sorry, if that's a naive question).
Pierrot and all--tho I have a couple of aucubas, I'm no expert on them. Would you also suspect sunburn...I note the bleached leaf areas near the blackened spots...I've certainly seen lots of this sort of damage on aucubas around here, a commonish problem. Tho most "shade" plants can actually do fine in full sun in our area, I seem to find aucubas are one that really don't like full sun, yet are totally dependable in a full shade situation. From conversations with folks in the Gulf states, U.S., I would also wonder if the problem would be low rather than high humidity. Our hot sunny days are normally so low in relative humidity.(For example, a gal I know in Mobile, Alabama grows hydrangeas in full sun (and 90% humidity, yuck!)with no damage. Mine get horribly scorched here every 30C plus day).
I tend to agree. I've seen some horribly sun scorched Acuba. The best you can do is provide mid-day shade and routine watering during the warmest part of summer.
