Yellow lichen

[cheops]

There is quite a lot of patches of yellow lichen growing on my cooking apple tree. None on the other apple trees. Should I be concerned or is it harmless. Thanks.

[Urban]

I was watching a program the other day, its supposed to be harmless, theres no hyphea that go into the tree

although it being there might be an indicator that the tree may not be too healthy, maybe it needs pruning to get rid of any dead branches, and let more air/light get to it

[Muddy_Boots]

Googled it says: A lichen is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi in a symbiotic relationship.

As also said on I think on an episode of Countryfile recently it said that Lichens on tree bark does no damage to the tree and is actually usually a sign that you are in a clean air area. You can actually encourage lichens to grow on new stone to give that aged look by painting on yoghurt when looks odd for a while but helps them to colonise quicker so makes the stone look older than it is.

[happyhumph]

As Urban says - not harmful to the tree itself but could be indicative of slow growth or poor air circulation.

Not always a sign of clean air - interesting segment on most recent GW that the colour can sometimes indicate pollutants e.g. higher levels of sulphur or nitrogen.

[cheops]

Well thanks everyone for all your input. A common theme was air circulation. That got me thinking - not on other fruit trees so why this one. It is beside a lattice heaving covered by a vigorous but beautifully scented honeysuckle. Sometimes it reaches out to this apple tree and I have to prune the encroaching honeysuckle. So I would imagine its poor air circulation but the lichen is harmless. I know Happyhumph says it can indicate pollutants but I live in a rural area and if it was pollutants why are the other trees not affected. Thanks everyone to get me thinking and feeling assured.

[Jungle Jane]

The colour of it can indicate pollutants,not the lichen itself I watched GW too,nice that birds can find microscopic life under there to eat in the winter.

[Guest]

Lichen will grow on slow growing wood as well as dead, damaged, diseased. So it might be the variety is not as vigorous as your other varieties or it could be pruning etc. as already mentioned.

[BUFFS]

I have had it on my fruit trees for years and they get plenty of air as we are so close to the sea, we get lots of gales blowing in. It just shows you have clean air where you are, I have a 10ins bonsai conker tree which has been covered in lichen for at least 2 decades and it and the 15yr old bonsai crab apples seem very happy, fruiting away and looking magic..