They look like they dried up and died from lack of water. That could be from drought, damage to the cambium layer on the main trunk or root damage. That is also what the electric utility easements all around me look like now.

The tall one looks like a Hinoki cypress, these are native to a very wet summer climate region.

looks to me like your shrubs got a good dose of roundup. Note the hioki in the corner looks fine. Are your shrubs growing under utility lines? Have your neighbor's shrubs been sprayed? Are you feuding with someone? Give us an idea where you live.

Thanks for your replies. I live in San Jose, CA. Just moved in this spring, and haven't got a chance to meet the neighbor on the other side since this is in my backyard. The shrub died before the heat wave a few weeks ago. yes, the far hinoki still looks good so if it is underwatering or some type of disease will that one be in danger as well?

Have you watered them at all since you moved in? This is not a disease problem.

I did water in the begining, but not regularly afterwards. I am pretty new in caring for trees and shrub, and wasn't sure how often I should water them and feared overwater. I just noticed that the one in corner is starting to show some yellow symptom too. Anything I could do to save it?

im wondering if the retaining board was adding to facilitate the house sale .. and they significantly changed the soil level before adding mulch ..

the brown grass is a fair indicator of the drought ...

the far plant might only have survived because it was in shade.. rather than blinding sunlight ... but it is probably also in drought.. and you might want to put a hose on trickle and let it run for a few hours... moving it around once in a while ...

both the plants are dead.. there will be no resurrection ... plan on removal.. when the weather cools ...

take into account.. the power lines.. when choosing new plants ...

ken

check this out: https://sites.google.com/site/tnarboretum/Home/planting-a-tree-or-shrub

In this climate you have to water regularly in the dry season. I just lost two large Chamaecyparis as a result of excessive heat and some irrigation problems. They, too, appeared to 'die overnight'. You are either going to have to water manually or install an irrigation system. Regularly means at least weekly, maybe more often.

Thanks a lot for all your feedback! I am learning so much about gardening this past few months. My newly planted lavendar also died, probably due to my over enthusiastic (daily) watering. It's been a fun process, but also sad when seeing plants being killed by my ignorance 😅

When you water, be sure to soak thoroughly so it gets down to the roots. You can gently dig down into the earth and see if it is wet or if just the top inch of dirt got water (your plants will die of thirst if that's the case).

This thread is a great example as to why posters should indicate location. I've never seen established shrubs die from drought like that, but then I'm posting from the mid-Atlantic. My state had 11.8" of rain in August, it's pouring now, and heavy rains in tomorrow's forecast.

I have heard on the news about the devastating wildfires in California and I realize it must be tinder dry.

L.. Times Article on xeriscaping which is landscaping with little or no additional water. Check out the beautiful pic in the article. I recommend xeriscaping for your area.

Looking at the shrub I'm wondering if it’s possibly Euonymus alatus. If it is perhaps it’s no great loss.

Sam the ambient daytime humidity here in summer is in the teens. And by August, when it hasn't rained in 4-5 months and the days are still fairly long, plants without sufficient irrigation are stressed. The only saving grace is that our typical nighttime temps are in the 50s and for those of us relatively near the water, we have moisture-filled sea breezes. But at this point I'm counting the days until the rains come!