Hi

the number one problem with growing lavender during a really hot summer is water.

Don't be afraid to pour the water on it. If your plants are looking weak or if the flowers haven't bloomed successfully water it.

If you have a drip system leave the water on all night 

then wait a week and do it again. You will be surprised at the difference in the plants. After the second all night go back to your regular watering schedule.

 

Mike