Possible honey fungus problem?

Tobykeane

(Copying post from fruit and veg as no response there)

Over the last few years the trees in our old orchard have slowly died and we believe it is because of honey fungus. Recently we dug down to the roots of the plum tree that dies last year and there was white underneath the sheath of the root bark. We have had a sort of honey fungus appear in the Autumn so put it down to that. The only thing is though is that we didn't see or could find any of the telltale black bootlaces associated with honey fungus. Are there different types? We also have a Warickshire drooper near by which has been looking worse for wear and I dug down yesterday and to my dismay when I hit a root I found the following:





Below is a picture of the Victoria plum that dies last year in the foreground. We left it like this to possibly put a climbing rose up it but unfortunately as we were digging a hole for it is when we found the roots had a similar look the the pictures above.



We also have a quince tree near by off to the right which is also this year starting to look a bit worse for ware and we are concerned it may be going the same way. What can we do?! It's getting to the point where we might not be able to have any fruit trees at all in the garden which is quite upsetting. From what I have read so far it sounds like we would need to do some serious ground work with a digger and digg everything thats infected out but that sounds like a seriously big job and not necessarily full proof. Any advice would be greatly welcomed! Thanks

BobTheGardener

It's virtually impossible to diagnose HF from those photos.  However, your description of the way it is spreading would be typical.  The rhizomrorphs can be difficult to spot without experience and often look just like black roots.  I've included a photo below which shows some I dug out recently.  Note the way two of them are connected by a bridge making an H shape?  Plant roots don't do that.  If you take a piece of suspected 'bootlace' and pull it, you will often hear the outer casing cracking in several places before it snaps - they are quite strong and flexible.

Honey Fungus cannot survive without a 'home base', which is usually a piece of dead wood under the soil (typically tree stumps.)  From there, the rhizomorphs spread radially outwards, searching for more dead wood/roots or a susceptible living woody plant to infect.  For that reason, I would advise that you dig-up and remove all dead tree stumps in the area, removing as much root as you can.

Then wait and see if any fruiting bodies appear later in the year and take photo's, ensuring you get shots of the underside of the caps and particularly of the stems.

Many regions suffered drought conditions last year and this has affected many trees, some of which are showing signs of stress this year, such as less blossom and fewer leaves than normal, so other factors like that could be involved.

Weakened trees are more susceptible to HF so if you don't normally feed your trees, doing that will help.  Try to keep at least a 1 metre circle free of grass and weeds at the base of each tree. 

BenCotto

I think it is an impossible task to dig out the roots so your best option is to live with the disease and concentrate on plants that have an inherent resistance. There is a full list on the RHS website.

But, first things first. How sure are you that it is honey fungus? Did you get an outbreak of fungi in early Autumn and have you lots of photos of them? Did the white fungal growth below the bark smell strongly of mushrooms?

If you’re a member of the RHS you can get excellent personalised advice from them. They appreciate photos. Similarly if you’re a subscriber to Gardening Which you can enlist the help of Matt Biggs. He was extremely helpful to me in helping to identify my outbreak.

There is also lots of online advice. This is a comprehensive, if now dated, article

https://www.forestresearch.gov.uk/research/archive-honey-fungus/

I would suggest - if you can - not worrying about it too much. It does not advance across your land like an invading Japanese knotweed and physical barriers like pond liner can be inserted into the soil to make a vertical barrier to contain it. How important is the orchard to you? Managed decay and reconfiguring that part of your garden might be your best option.

Tobykeane

BobTheGardener said:

It's virtually impossible to diagnose HF from those photos.  However, your description of the way it is spreading would be typical.  The rhizomrorphs can be difficult to spot without experience and often look just like black roots.  I've included a photo below which shows some I dug out recently.  Note the way two of them are connected by a bridge making an H shape?  Plant roots don't do that.  If you take a piece of suspected 'bootlace' and pull it, you will often hear the outer casing cracking in several places before it snaps - they are quite strong and flexible.

Honey Fungus cannot survive without a 'home base', which is usually a piece of dead wood under the soil (typically tree stumps.)  From there, the rhizomorphs spread radially outwards, searching for more dead wood/roots or a susceptible living woody plant to infect.  For that reason, I would advise that you dig-up and remove all dead tree stumps in the area, removing as much root as you can.

Then wait and see if any fruiting bodies appear later in the year and take photo's, ensuring you get shots of the underside of the caps and particularly of the stems.

Many regions suffered drought conditions last year and this has affected many trees, some of which are showing signs of stress this year, such as less blossom and fewer leaves than normal, so other factors like that could be involved.

Weakened trees are more susceptible to HF so if you don't normally feed your trees, doing that will help.  Try to keep at least a 1 metre circle free of grass and weeds at the base of each tree. 

thank you for both your inputs. Bob, I have actually seen this. But when I broke into it I thought it was a root fibre as it broke apart into an outer casing with a white middle. On just taking a quick glance at this https://www.forestresearch.gov.uk/research/archive-honey-fungus/
I noticed this picture 

and I am pretty sure that is what I saw. Mad how funguses work, not soft or squishy at all but just like a root. Fascinating. You are right thought as well, we have never fed the trees in the orchard, they were always here when we moved over 35 years ago (the apple trees and Warwickshire drooper) and we have put in a few others in since but not really looked after them properly it would seem. I think the plan of action will be to first make sure we feed the current trees and remove grass from around the base, and then look to how expensive it's going to be to get a digger in to dig up the roots. A mate of mine reckons he can hire a mini digger for about £100 a day (he's a tree surgeon), so might look into that.

Thanks again

Toby