Sorbus plantings in a row
#9 Sorbus, Jerusalem Pear,
Mountain Ash

This site is slightly to the west behind the barn. Sorbus just to left of Docent in white hat. Note the trees planted in a north-south row as were all the plantings on GRF. Ripe Sorbus in Fall below.
Sorbus with ripe fruit in fall
Sorbus is beautifully colored in autumn.
Note the fruit about the size of small plums hanging in dense clusters.

The Bletting Sorbus

One of the unusual plants found growing at Luther Burbank’s Gold Ridge Experiment Farm in Sebastopol is Sorbus domestica, which goes by the common names of Mountain Ash and Jerusalem Pear. At this time of year farm volunteers are frequently asked by visitors about this remarkable tree with attractive fruit.

Farm volunteers are well acquainted with the fruit. Over the years all of us have put in many hours raking it off the paths. Our Sorbus trees are prolific!

The mature trees found standing in North-South rows (the usual configuration of Burbank’s plantings) are about 30 feet tall. Members of the rose family, they have pinnate leaves which are grayish on the underside. In spring the trees are covered with white clusters of blossoms. These ripen into yellow-red apple-like fruits about 1 ¼ inch in diameter. The fruit begins falling from the trees in early September and can continue into early December.

The fruit is not edible when picked from the tree. It is astringent and will pucker your mouth like a persimmon does. To be edible it must “blet”, which means to over-ripen. On the ground it will become brown and soft, at which time it is edible. Some have described it as having a chocolate flavor, while others say it tastes like fermenting applesauce. It can be used in baking to substitute for bananas or applesauce in quick breads, although it is a lot of work to prepare the pulp and much of the flavor is lost in baking. The best use of Sorbus in food that we volunteers have found is in ice cream. A few cups of pulp added to a recipe of vanilla ice cream is delicious!

Most of the fruit that falls from our trees sits on the ground and blets. We rake the paths every week so that visitors will not have to walk through the squishy mess. All these fermenting fruits produce an aroma that is quite different from that of fallen apples, but evokes the same feeling of autumn.

A visit to Luther Burbank’s Gold Ridge Experiment Farm in autumn will give you a chance to experience the bletting sorbus first-hand.



Revised February 25, 2009