My husband and I planted 3 limelight hydrangea trees on Sunday afternoon. Our backyard gets a lot of a direct sunlight, and the temps here have been well into the 90s this week, and won't let up probably until the end of the summer.

My question is: how often should we water these trees to keep them happy? I am so worried about over-watering them.

Last night, I noticed one of them had droopy leaves. My husband believes it was because it needed more water, so he went out and gave them all a good watering.

What amount/frequency of watering is sufficient when they are planted in an area with direct afternoon sun and heat?

Thank you!!