I got my hydrangea for about 2 weeks now. I put it in a spot where it gets morning sun until 2pm. It was doing ok for a while, but on Sunday, it got seriously sunburn. The huge leaves just became crispy dry. I don't get it, the soil is still moist, the sun didn't sudenly beame stronger on the same spot. How could it happen?
Now, I moved it under the balcony where it gets full shade.
When it gets very hot a lot of plants lose more water through the leaves than they can take up throught the roots causing them to wilt. Probably what happened in your case. Did it perk back up after being out of the sun?
Those leaves never got droopy even when they got sunburnt. They just become completely dry and crisp to the touch. I still got half of the leaves left without being burnt and they stay green in full shade now.
I heard that they can stay in full sun in coastal southern california and didn't expect they got burnt so easily.
Couple things...how hot has it been lately? If you've had a warm spell and you're in a situation of borderline too much sun that could cause problems. Secondly--how much sun was it getting at the nursery or wherever you bought it from? If they had it in a mostly shady area, then you'd need to adjust it gradually to the higher amount of sun or else it can get burnt. Leaves can sunburn without wilting (I have it happen every year when I pull things out of the greenhouse to an area where they get a little stronger sun--nothing ever wilts but invariably a few things end up with some sunburned leaves) And lastly it could just be transplant shock--when you plant things in the summer it's not at all uncommon for the plant to have a little trouble adjusting.
I am trying to figure out the reasons for the burnt leave.
I bought the plant from costco. I really don't know how are they kept in nursery but I think it has been kept in the warehouse on shelf for a few days.
The weather in coastal san diego has been typical June Gloom. We got marain layer in the mornings and burning sun after around 11am. And the spot I kept the hydrangea gets in shade after 2:30pm.
And the wierd thing is It got suddenly sunburned after 2 weeks under my care.
I just hope it is going to survive and recover under full shade. Having my fingure crossed! What can I do to help it to adapt better? When can I give it some fertilizer?
My guess is that when it was at Costco it wasn't getting as much sun as it did when you brought it home. Sunburn can take some time to show up--the first few days often the plant will look just fine, then it'll get some bleached out areas on the leaves, then those areas will eventually turn brown. If you weren't paying close attention, you might not notice it until they get to the brown crispy stage because that's when the damage really becomes obvious.
The good news is that except for seedlings or very small plants, I've never had anything die from sunburn so your plant may look a bit ugly for a while but it should be fine. If you keep it in the shade to recover, make sure you adjust it gradually to higher light levels when you eventually move it back to the spot you wanted it, otherwise the same thing could happen all over again. I would probably hold off on fertilizing it until you're sure it's not stressed anymore.