Pruning A Burned Hydrangea In Drought

Question

In California, my hydrangeas are getting sunburned and seem to be dying off by mid-August. Should I cut off the burned flowers, back to the emerging buds, or should I cut the whole plant back to the ground? The heat continues now in September; we are having 10 days over 100 degrees and have had no rainfall since February. We use drip irrigation, so the plants do get water, but the air is so dry and the sun is so hot that I think the plant might survive best underground.

Answer 1

Some of the stems may be alive but leafless. They can either leaf out once temperatures recede or wait until spring. Dead stems will not leaf out in spring and can be pruned if they fail to leaf out as late as the end of May. Panicle hydrangeas can be given late afternoon shade while the other types of hydrangea should receive shade by 11am or earlier. For a new shrub not yet acclimated, you can provide temporary shade with large umbrellas, sheets, 35% shade cloth, etc. if practical. The soil should always be mulched (3-4” year around) and be kept always moist at a depth of 4” in the summer or in dry, warm winters.