The Double Tree of Casorzo

June is a gorgeous time in the garden… the planting is finished, the weather is warm, and wow… the irises, peonies, poppies, mock orange and roses are in full bloom. Lettuce, kale, choi, basilico, garlic scapes and rhubarb give us the first taste of the year. Soon strawberries, peas and onions will join in. This is a great time to sit back and enjoy!

Today, we wanted to share an interesting little arboreal tidbit from Enrique Arayata at Russell Tree Experts:

“Today, I share with you a rare and interesting sight: the Double Tree of Casorzo.  Between the towns of Casorzo and Grana, in Piemonte, a region in northwest Italy, there is a cherry tree growing healthily on top of a mulberry tree with branches spreading over 5 meters long. It is known as the Double Tree of Casorzo (Bialbero de Casorzo in Italian) or the Grana Double Tree.

As you may already know, it is not common by any means to see a tree on top of another tree, but somehow, someway, this cherry tree managed to find its home on top of this mulberry tree. It is unclear how exactly this double tree grew to be, but one popular theory is that a bird dropped off a cherry tree seed on top of the mulberry tree. The cherry tree seed then spread its roots down through the hollow trunk of the mulberry tree and found a connection to the soil where it can absorb nutrients. The relationship between the two trees does not appear to be parasitic or harmful to one another. It is fascinating to see that the mulberry and cherry trees are able to share water, sunlight, soil nutrients, and most importantly space without outcompeting one another and growing just fine. 

Plants growing non-parasitically on top of other plants are not uncommon and are known as epiphytes. Common examples of epiphytes include some species of ferns, orchids, and bromeliads, which can attach themselves to trees or other plants and absorb some nutrients from rain and air along with any other nearby debris or soil they can access; all while not harming its host. What makes the Double Tree of Casorzo unique is that most epiphytes either are small in size or have a short lifespan due to lack of space and humus. However, as you can see in the photo within this article, this cherry tree is quite tall and healthy! “

https://www.russelltreeexperts.com/arbor-ed/2022/5/12/double-tree
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