European Beech Trees / Gold Dawyck Beech have lost their leaves in winter

(Question)

Hello! I live in Toronto and we had 15 European Beech trees planted along our backyard property line for privacy in May. We get about 5 hrs of direct sun per day in the spring and summer and have an irrigation system in place to provide proper watering. It was my understanding that the leaves of these trees dry and turn copper in the fall and most of the leaves are retained throughout the winter, shedding when the new buds are ready to bloom for new spring leaves. That didn’t happen! Our trees are completely bare and we now have no privacy until the Spring hits again. Is there any way I can encourage the leave to remain? Fertilizer? Anything? I’m not sure why this happened. Thank you!

(Answer)

Thank you very much for posing such an interesting question to the Toronto Master Gardeners: Why have your beech trees lost their leaves in winter?

As you suspected, I think the 15 Beech trees that you are growing are probably Fagus sylvatica (European ‘Dawyck Gold’ beech). They make a very good privacy hedge. The Dawyck Gold grows slowly, but it will reach a height of about 45 to 50 feet. However, it has a narrow, upright columnar growth with a spread of only 10-15 feet.

You have chosen very attractive trees for your privacy hedge. The leaves emerge gold in spring, and turn an attractive lime green in summer. The serrated pointy leaves are highly ornamental. They turn an outstanding coppery-bronze in the fall. The smooth silver bark is extremely showy and adds significant winter interest. However, this variety of beech, the Dawyck Gold, seems to be a variety of beech that drops its leaves in the Fall.

I believe you may be growing one of the varieties of beech tree that cannot meet your needs for privacy throughout the year. Only some beech trees hang onto their leaves (are “marcescent”) through the winter: Fagus Sylvatica American Beech; and Sylvatica Atropurpurea Copper Beech are two of them. However, I need to highlight that I found some contradictions in the websites I read. A couple of British and an Irish nursery that sell Dawyck Gold beech trees advertise that they hang onto their leaves through the winter. However, it is much warmer in the UK than here.

Since there is this contradiction, and there seems to be some indication that Dawyck Gold beech trees could be marcescent (at least in the UK), it may be worth exploring these suggestions that I read about: Marcescens is particularly notable in juvenile trees, so maybe pruning your beech trees to 8 foot may help. Also do not fertilize. Marcescens is encouraged if the soil is dry and infertile, since marcescens is adaptive to these conditions.

The reason why some trees are “marcescent” (holding onto its crinkled leaves on the canopy throughout the winter), is still being debated, but it is species-specific. An excellent article that explores this can be found at:
https://northernwoodlands.org/articles/article/why-do-some-leaves-persist-on-beech-and-oak-trees-well-into-winter

My final thought is that you seem very surprised that your beech trees did not hang onto their leaves. Were you told they would? You could consider going back to the nursery and asking them to replace the beech trees that they sold you with another variety that will hang onto their leaves. One of our Master Gardeners says that she planted Ironwood, Ostrya virginiana, a native understory tree, this spring, and it is hanging onto its leaves and is providing a very nice privacy screen. It grows 18 m (59 ft) tall and has a 20–50 centimetres (8–20 in) trunk.

Happy growing!