Everyone can enjoy the splendour of the Autumn colours in our local woodlands at this time of year. In this edition, I thought I would highlight some of the strange and lesser known fungi that can be found growing on trees throughout the year but especially in the Autumn months.

There are hundreds of species of fungi associated with trees in this country. Many of these can cause trees to become diseased and unsafe as they degrade wood and affect the structural integrity of roots, stems and branches.

As trained arborists, we need to have a good knowledge of these fungi and how they interact with the trees that we are responsible for.

I have picked out a selection of fungi that I have found and photographed on trees this year. All of them impact on tree health and safety to varying degrees.

Kretzscmaria deusta – Brittle Cinder

This fungus really is a nasty little rotter !

Kretzchmaria deusta, or Brittle Cinder is a common fungus on mature broadleaved trees, especially Beech, Lime and Horse Chestnut.

It causes a soft rot through the base of trees close to ground level that can lead to a sudden fracture even on windless days.

It is easy to miss as it blends in with the bark, hidden between the buttress roots on otherwise healthy looking trees.

This is definitely one that we look out for when we carry out tree inspections for clients, particularly on larger old trees close to property and roads.

Phaeoluus schwientitzii

The Dyer’s Mazegill and Fomitopsis pinicola – The Red-Banded Polypore

Both of these weird looking fungi can be found growing as ‘brackets’ at the base of large old conifers. The fresh growth of new brackets are sometimes seen in late Summer through into the Autumn. They both cause a brown rot in the heartwood of affected trees. When this decay becomes more established this can lead to a sudden fracture and windthrow of affected trees.

Neither of these fungi are commonly found in garden trees but something that as arborists we should be aware of when we are inspecting trees because they can have implications for tree safety although trees may live on for many years with these fungi slowly digesting the heartwood.

Fomes fomitarius

Another bracket fungus often seen on broadleaved trees is Fomes fomitarius, commonly known as Tinder Fungus. This also causes a white rot on a range of broadleaved trees, sometimes in the main stem but also in larger limbs and can lead to a brittle fracture in infected trees. It is called Tinder Fungus because when dried it can take a spark to produce a smouldering ember from which a fire can be started. This was a vital skill to prehistoric man going back thousands of years and still used today amongst bushcraft enthusiasts.

Grifola frondosa
– Hen of the Woods

Another fungus found in the Autumn months is Grifola frondosa or Hen of the Woods. This produces a white rot in the base and buttress roots of mainly older Oak and Sweet Chestnut trees. In Japanese culture this fungus is known as ‘Maitake’ and is gathered for its culinary and medicinal qualities.

Armillaria mellea – Honey Fungus

The next fungus that is shown below is Armillaria mellea, commonly know as Honey Fungus. It carries a justifiably fearsome reputation for wreaking havoc in gardens. This is a common fungus, found on a wide range of trees and shrubs.

It causes a white rot in the buttress and main roots that can kill off trees within a couple of years and will increase the risk of windthrow as roots become increasingly decayed.

There are no easy solutions to this when it becomes established in a garden environment. We generally recommend removal of infected trees as well as their stumps and replacement with species that are more resistant to the fungus.

Four Seasons Tree Care have a very broad experience in inspecting, advising and working on trees, especially larger, older specimens. So, if you have any concerns for the safety of trees on your property or feel that some expert tree surgery may be appropriate then please do give Four Seasons Tree Care a call.