Looking great in the garden, as we turn the page on a new year is the Japanese bay tree. I first met Machilus thunbergii (Lauraceae) thanks to my horticultural mentor, the late J.C. Raulston, who extolled the virtues of this evergreen tree, native to Taiwan, Southern China, Vietnam, Korea, and Japan. J.C. had been frustrated, however, at the lack of winter hardiness in Zone 7b, Raleigh, NC. In the early 1990s, his solution was to plant out row of seedlings, several hundred foot long row, and see if any showed better hardiness, and if so, then do clonal propagation. Sadly, none of the seedlings at the arboretum proved reliably winter hardy. Machilus thunbergii is a coastal plant that needs summer heat to thrive and develop good winter hardiness.
In fall 1997, I found myself botanizing on Korea’s Ulleung Island. Since this was the source of some of the most winter hardy camellias ever collected, I had my eyes out for other broadleaf evergreens, when I spotted none other than Machilus thunbergii in full fruit. The resultant plants in our garden are now 45′ tall. The photo below is a seven year-old seedling from our original collection. None of our plants have ever seen the first bit of winter damage in 27 years. In spring, the newly emerging foliage is a lovely cinnamon color.
Taxonomically, Machilus thunbergii has been the subject of a botanical tug of war between those who think it should remain a Machilus, and those who want to re-home it in the genus, Persea. In Asia, the bark is used to make a mosquito repellant (makko), as well as skin care products. It is also used to treat allergies and stomach ulcers, while new research is focusing on its use to treat dementia. If this is of interest, our friends at Garden Treasures Nursery are currently offering offspring of our Korean collection.
