Various established plants dying bit by in bit in one area of garden

Rushy

Hello,

I have two well established lilacs very close together - one of which started to look a little poorly earlier this year. Leaves stated to wilt and eventually shrivelled and fell off. It appeared to affect a couple of branches at a time - rather than the whole plant. Shortly after I noticed that a large nearby privet also started to die off on one side. Then the second lilac started to wilt. The privet is now completely dead. The first lilac is largely bare with a few new shoots pushing out from existing branches (although some of these look similarly doomed).

Now in a similar manner a mock orange has started to wilt on several branches (see photo) whilst the rest of the plant still looks healthy.

 

 A very nearby copper beach hedge still appears very healthy.

I've only scraped just below the soil around the lilac but the roots appear to be healthy (well certainly the base of the trunk. Bark is splitting on larger branches - almost like the stem has contracted inside it.

The lilac must be 30yrs old and has always been strong. The privet is 15+. The mock orange about 10yrs. All have been perfectly happy until now.

I have no idea what is causing this or what to do. Should I be looking out for any clues in particular?

Thank you!

Rushy

Here's a photo of the lilac:

 

pansyface

I think it might be phytophthora.

https://www.rhs.org.uk/advice/profile?pid=542

 

Rushy

Thanks for the replies. I had a wysteria rot out on me a couple of years ago (in the front garden). The rot was certainly obvious at the stem (it actually snapped off) - I can't see anything on these plants but have not had a good dig around. But come to think of it, it did behave in a very similar manner. The other thing is, in the RHS description you kindly linked to, it seems to say it is mostly a problem with waterlogged soil - although this is usually very dry.

 

How persistent is it? How much soil do you need to get rid of? And how do I protect nearby plants?

pansyface

The "bit by bit" doesn't sound like honey fungus -at least not the honey fungus that I had here.

Rushy

These are photos from the lilac base. Curiously, none of the wood is soft. It does not feel rotten.

 

 

 

pansyface

That, I would say, is honey fungus. Or at least it looks like bad news. Follow the RHS advice for what to do about it.