I'm afraid that there's nothing but bad news here. The plants are Photinia fraseri, known as red tip photinia. This plant is severely impacted by a fungal disease caused by Entomosporium maculatum.

The disease is so destructive to this plant that red tips have been on the 'do not plant' list for many years.

There are fungicides that can help with entomosporium leaf spot but I sure wouldn't recommend treatment in your situation. Your plants have been infected for years and there are so many of them; I doubt very much that they could ever completely recover.

Fungus diseases build up resistance to fungicides, too.

My first suggestion is to remove the shrubs entirely and replace with something completely different. Another alternative is to cut the plants all of the way to the ground, removing and destroying every single bit of the red tip debris including all of the old, fallen leaves. Rake out the bed, remulch, and wait for the new growth to emerge from the base.

Be sure to keep your sprayer and chemicals on hand because the disease will strike again, guaranteed.

Agree 100% with the above!! Red tip photnia are seriously troubled by this leaf spot in the Puget Sound area, to the point where most reputable nurseries (NOT the box stores) no longer sell them or recommend them. Do yourself a BIG favor and remove them and replace with something less problematic - there are no shortage of suitable replacements for this area :-) You will need to be spraying endlessly to control this disease and it is just simply not worth the time, effort and expense - not to mention the impact of spreading of strong fungicides into the environment - for a disease that you will never be completely rid of.

a good example of why a monoculture should never be planted ...

when you do replace.. do yourself a favor.. and do NOT plant all of one plant ... diversity rules ...

ken

Ken, are you saying there's never a call for growing a uniform hedge? I think 'hedge', by strict definition, would be a barrier created by growing one type of plant, usually pruned into a dense line.

Ken is a "never" kind of guy.....never fertilize trees, a conifer is never a shrub, never plant a uniform hedge. Grain of salt.

Oh no! I am absolutely heartbroken to hear this. The hedge of these trees is beautiful - and they've been around forever - I hate to hear that they have to go. Can this fungus affect other trees / bushes / plants in the yard? Should I get them out of there fast or do I have some time (I have LOTS of projects at this house).

Depends on the plant but in general, no, they won't infect other trees and shrubs. And you can leave them indefinitely - as long as you can stand looking at them :-) Now that you know what they are, I'll bet you recognize them in gardens all over, looking pretty much the way they do in yours and often much worse (barely any leaves at all or just on the branch tips). And you can replace them in stages if you wish, a few at a time.

Now and again you will see a stand-alone specimen, often of considerable size, that looks clean and unblemished. But it is just a matter of time :-(

btw, they are considered to be shrubs rather than trees, although they can grow to some considerable, tree-like sizes. Much like an English laurel.

Thank you everyone for your comments - I am sad that these shrubs :) (not trees) have to go. But at least I know what's going on now.

One more (maybe odd) question - the fungus won't hurt pets will it? I am thinking of my dog who likes to roll around in leaves and grass...

If you really love the plant, why not try and keep one (or more)? The first photo seems to suggest that there are still a few with a good amount of foliage. Pick the healthiest looking plant(s) and remove the rest. Spend the next 12 months removing every last leaf that falls on the ground to mitigate the perpetuation of the fungus, improving the draining, and monitoring the plant's progress. Don't forget to keep the pruning shears in the shed. The continual shearing of these plants to make them something that they aren't (a hedge) keeps them in a perpetual state of stress. There's a reason the only mature ones you see now and then aren't hedges... They can be very beautiful if allowed to grow into a more natural form. If you force their form, they give up in short order.

Because of this, it's much more advisable to prune as little as possible. For the next 12 months, it's pretty much mandatory if you want to give the remaining plant a chance to survive.

It's up to you, but it's far from a definitive total loss. If this was my yard, I'd remove the really sick looking ones, keep only healthy plants that are at least 15' apart or so, ensure I don't have a drainage issue, and rake any fallen leaves.

Thank you - I may give this a try - I have nothing to lose!

MS, plant diseases are not transmissible to animals.

Thank you. (My dog thanks you too )