Hello, and thank you for this question! Ironically, I was in your neck of the woods last weekend. Our best friends live in Surf Pines, and we spent a lovely weekend with them. We are up there quite often so if we don't get this resolved soon, I'll happily do a site visit next time I'm that way.

So before we get too far, I'll do my best to answer this, but it might be the case where I need a bit more information and some pictures would be so helpful! 

Let's start out with where my thoughts went first, which is your watering set up. Trees and large shrubs really prefer a deep root-soaking water unlike shrubs and flowers, which really like that overhead spray. This is for two reasons; one being that the roots do much better (in terms of growth and establishment) when they are soaked, but also, pathogens can spread more easily with overhead irrigation, especially in humid, coastal air, creates perfect conditions for fungal spread. 

This brings me to my second thought, fungal diseases as you mentioned in your question. Admittedly, I don't know much about these so I did a little reading and here is what I found. Here are two that affect junipers- Phomopsis blight or Kabatina blight are my top suspects. Both create brown tips that progress inward, black dots (spore-producing structures), and eventual dieback. 

I'm also wondering about salt. How close do you live to the ocean? Salt could desiccate the plants, but I think you'd have to live extremely close to the ocean.

Now to your questions;p
1. its absolutely okay to cut the brown off.  Go ahead and prune out any brown, brittle, or dead foliage. This won’t harm the plant and may help reduce fungal spread if disease is present. Be sure to use clean, sharp pruners and disinfect blades with rubbing alcohol between plants

2. I got ahead of myself and answered that already in the first part!

3. I think you should pruning the deadwood out and switching your method of watering first, and if that doesn't help, we can look into some other treatments. 

4. I don't know a ton about junipers, but I do have a really thick book about tree and shrub varieties! It looks like Juniperus conferta ‘Blue Pacific’ Spreading (12–18" tall), Juniperus horizontalis ‘Wiltonii’ (Blue Rug), or Juniperus chinensis ‘Saybrook Gold’ seem to be relatively resistant to blights. 

I know this is a lot and I sort of posed more questions than answers but let me know what you think and we can go from there! If you would like to reach out to me directly, my email is <personal data hidden>.

Thank you!
Jennifer 

Hi there,

Thanks for the additional pics. It really is hard to say! OH! Here's a question that literally just popped into my head. Do you have dogs or is this on your property where people walk by with doggos? I have seen more than enough plant damage from doggie urine! I realize I'm supposed to be the expert here but I'm stumped (pun absolutely intended!).

Jennifer 



Sounds great, please let me know how they do!