The pics look like it is pretty far advanced. Were there white splotches on the underside of the leaves?

Also, when was the last time you cut the plant back to the ground?

I never noticed white splotches, though to be fair I haven't given the plants a close up look in a little while. I've also never cut them back. Perhaps I should have, but I thought it best to leave them alone and treat them like mother nature would.

Also let it be known I'm quite new to gardening! Thought starting off with natives would be easy... haha

Thanks, that's super helpful! They are being watered, and that might be the culprit. They are planted pretty close to a young pomegranate tree, and they (the three poppies and the tree) are all on a drip line system that goes off twice a week. I think I'll turn that off, and begin deep watering only the pomegranate tree once a week. The poppies have had zero fertilizer or compost.

Even with stopping the watering now, are they doomed? Maybe I should try some organic fungicide like Serenade?

You won't know if they're doomed until they die. I'd cut off the watering and spray them thoroughly with Serenade.

Even if they appear to die, you might want to cut them down and wait until after the winter rains have come to see if there's any regrowth.

jxbrown, I'll do exactly that, thanks. Fingers crossed they pull through!

What sort of drip irrigation do you have? Is it 1/2" drip tube with built in emitters or is 1/4" spaghetti tube with emitters on the ends? How is it positioned aroud the plants. Drip irrigation can be the easiest way to kill natives if not done right.

It would normally go dormant in the summer and die back, so if it looks like hell cut it back. Just don't throw it in the yard waste bin use the trash. You don't want to go spreading disease.

Also, a deep watering for an established pomegranate would be more like once or twice a month, not weekly.

I didn't install the irrigation myself, but it's definitely not spaghetti tube. More like the 1/2" tube (might even be 1"), with holes in it (is that what built in emitters are?). All of what I'm learning here is why I'm really glad I'm taking this into my own hands now, instead of relying on others who may not have had the best approach...

There are three lines about 1/2 foot apart that runs through the area where all the plants are in. The more I'm learning, the more I realize I must have been drowning the poor things. :(

Are you recommending I cut it back now, in order to preserve the plant? Despite all three of them being quite infected looking at their bases, they are still flowering, and their upper portions don't look so bad. I'd be sad to cut them off now and miss more blooms, but if it's what's best for the plant then I will. As far as cutting back to the ground, is that literally exactly what I would do? Or leave a few inches of the plant left? The details are really helpful for me.

Thanks for the tip about watering the pomegranate! I'm very new to gardening and really appreciate all the helpful advice everyone!

Also reviewing the last photo in the original post I'm way off on my estimate of the lines being 1/2 foot apart from each other, more like 1.5-2 feet apart.

So I looked at the photo more closely and realized the answer was in the pic. You have 1/2" poly tubing with 1/4" spaghetti lines attached. I'm not a fan of these types of installations. That means you have individual emitters placed around the plants. In order to have any idea how much water you are laying down you need to know what the drip rate is and how many dripers there are per the area. Turn the circuit off for now. You're coastal so you can probably leave it off for the next month and not even notice.

I wouldn't cut them back just yet, but as soon as they really start to look awful, chop them back.

Thanks for catching that! They are off now. I'll probably leave them off until October after all the feedback from this thread! My plan is to continue to fill the hill in with natives, so I'm beginning to think the existing irrigation may not be a good fit for that anyway.

If you are on a hill and decide to put in a different irrigation system, I recommend MP Rotators. They were designed for windy hillside areas and have a low precipitation rate.