Rather than using a meter, which are notoriously inaccurate, get your fingers down in the soil to assess how damp it is. If necessary dig a hole. I see there is an irrigation emitter there. How much water and how often is it pushing out? Lavender really doesn't need constant moisture. I notice the shrub behind is also yellowing.

It’s getting watered regularly as is the hibiscus behind it but the yellowing was very sudden and rapid on all.

As said on your duplicate post, lavender should not be watered ’regularly’.

As Floral said, you are overwatering your lavender. It may or may not recover, depending on how mushy the roots are. Your climate is Mediterranean and lavender is perfectly suited to your conditions, including dry summers. You should give your lavender additional water the first year in the ground to help it get established because the rootball is still small. But always check the soil with your finger to make sure it dries out slightly between watering.

Is there a way you can take it off the irrigation system and water by hand?

It also helps to mulch them with gravel (not hardwood/bark chips) but I understand if you want a certain look for your garden. Just keep in mind that your mulch will also absorb water and it will increase moisture levels in the soil and humidity around the plants.

in the very many years i have been on the forums.. this is one plant.. that a vast majority of peeps have given up on .. if its not one thing.. its another .. and so on... and after multiple failures.. peeps just move on ...

the list of problems begin with winter in colder areas .. moisture in winter or dormancy ... rotting roots ... soil not conducive to L .. which means drainage and root rot ... etc.. etc.. etc .. it get woody and ugly if you do manage to grow it for a few years ... etc.. etc.. etc ...

and just about every time i say that.. in rolls the 3 peeps who grow it like a weed and have a couple acres of it ... lol ...

one definition of a green thumb is that you kill every plant 3 times.. and this is one that is that top of that list.. lol ... but after 3 times.. just give up ...

i like and agree with all the advice above .. but i dont think you are doing much wrong.. its just this plant ...

try again.. but in the back of your head .... let a little hate grow.. until you also give up ...

ken

Oh, come off it, Ken. Sorry, but you could not be more wrong. Lavender is not going to be tricky in LA if the OP just stops overwatering. Please don't spread gloom and misinformation based on your experience in a totally different climate. As JoJo says above, Lavender is perfectly suited to life in California.

Yes, the American West is perfect for lavender, and not just the coastal areas.

I have to water my lavenders at least once a week in the Mohave desert, but even I have to reduce the amount of water in the summer. They don't like to sit in warm, wet soil or the yellowing and droopiness start to set in immediately and the roots get mushy.

If I cut back on the watering (if there’s a suggested schedule please let me know) I’m hoping it recovers. I haven’t been using the irrigation system lately as there are leaks, and have been watering by hand.

Try not to think in terms of ‘schedules’ for watering anything. You need to assess whether the plant actually needs water. Have you felt the soil a few inches down? Lavender is a Mediterranean plant and evolved in a climate where it could go for weeks without rain.

I notice that the Hibiscus is also yellowing. So, is it possible there’s something else going on? What is that big pipe? Could you pull back a bit with the camera and show us the wider surroundings to see if there’s anything suspicious?

When should I be watering the lavender? It’s been 100° and I haven’t watered since everyone seems to agree it’s overwatering. It looks sickly and sad but still has green in places. Hibiscus is flowering but still yellow leaves