Looks like it has dried out. Depending on emitter rate, 10 minutes on drip irrigation is not very much. I would suggest testing to see how deeply into the soil the water percolates at that rate - you may need to increase the timing.

is that white wall south facing...??

is it a new transplant???

better pic please

ken

Agree with gardengal. You can shear this back and eliminate the dead leaves. Around here (Sonoma County, Sunset zone 15) most Hebes do better with some shade from afternoon sun. If in full sun, need more water.

Thanks all. It's south facing. I will trim dead leaves and up the water. Thanks

Partial burn may indicate it was actually another problem (than drying of the soil) - the concentration of the dead parts mostly near the wall could reinforce the idea that it was sun damage. In which case it is going to keep happening during hot weather each year unless you try this same kind of shrub in a different spot.

As far as soil moisture is concerned dig around in the dirt and look at it to try and find out if it seems at this point to be too dry or too wet. Working some mulch in around the plants (as can best be done in this tight space) might help them out a bit also. After you cut them back down below the dead this should become more feasible.