The Carlisle Mosquito Online

Friday, September 14, 2007


Autumn olive

Part of the celebration of Riverfest and Mass Biodiversity Days in June was a walk at Great Brook Farm State Park to teach "Foraging for Wild Edibles" led by Russ Cohen. Prior to the walk, he handed around some fruit leather he had made from autumn olive berries collected the previous fall. Most people seemed to like it. On the walk, Russ pointed out two little autumn olive bushes between the new parking lot and the ice cream stand. I checked them on Sunday, September 9 and discovered that neither of the puny bushes set any fruit this year. This is good news for the habitat and the native flora since the plant is now known to be an undesirable invasive alien.

The autumn olive, with red or pinkish-red berries and shiny leaves, is one of Carlisle's invasives.

Banned in Boston. Since January 1, 2006, autumn olive propagation and sales have been prohibited in Massachusetts. It's a story of unintended consequences that started in 1830 when the plant was deliberately introduced into the U.S. from Japan for the purpose of cultivation. In New England the trouble didn't start until the 1940s when it was widely used to revegetate disturbed habitats. It can tolerate poor soils because it is able to fix nitrogen in its roots. The berries are prolific and birds find them attractive so the seeds were distributed widely. Then in 1963 an especially heavy-bearing cultivar called "Cardinal" was introduced and marketed by the nursery trade. The birds were probably happy but the invasive nature of the plant became ever more apparent until finally in 2006 new sales of all autumn olive were banned.

Name. Autumn olive is Elaeagnus umbellata, a member of the oleaster family and is sometimes called oleaster or Japanese silverberry. It is unrelated to true olives and the fruit is nothing like an olive. The leaves are perhaps suggestive of a real olive tree.

These autumn olive berries show the little silver scales that are the basis for its other name, Japanese silverberry.
Identification. Autumn olive is a multi-stemmed shrub which reaches about 15 to 20 feet in height. You can sometimes spot it from a distance because the underside of the leaves is silvery and stands out against the darker green above. It flowers in April and May with clusters of small pale yellow flowers. This time of year it is laden with ripening berries on short stalks clustered around the twigs. The berries are about a quarter inch across and red or pinkish-red with silver scales. They have a single seed with a few longitudinal ridges.

Control. Carlisle has a much bigger problem with other invasive species like buckthorn, bittersweet, multiflora rose, and burning bush, but if you find some autumn olive with fruit you can help slow the spread by eating the berries. Caution. Just as with mushrooms, be sure of the identification before you eat berries found in the wild. I found some very berry-laden bushes in Chelmsford under the high-tension power lines that cross the road near the Triangle Service Station. I collected a few pounds (with care because some of the bushes have thorns) and heated them in a saucepan until they released their liquid and then simmered them for about five minutes. You need to remove the seeds by pushing the pulp through a sieve or using a food mill. You get nearly a cup of pulp from a pound of berries. You can then dry the pulp into fruit leather — you don't need to add any sugar — or you could use it in recipes for pies, muffins, ice cream, etc.

Steve Brill, the New York forager, says the flavor is reminiscent of raspberries, pomegranates and cranberries. There is nutritional benefit too, since autumn olives have a very high lycopene content.

References. Guide to Invasive Plants in Massachusetts, Paul Somers, Rachel Kramer, Karen Lombard and Bill Brumback; Autumn Olive: Weed or Cash Crop, Brent Black and Ingrid Fordham; The Wild Vegetarian Cookbook, Steve Brill.

Autumn Olive and Apple Tart

I adapted this recipe from an old cranberry walnut tart recipe. I tried it on some friends and it was well received.

Precook a pastry shell in a 10- or 11- inch tart pan with fluted sides and removable bottom.

Make the filling with:

3 large eggs

1/2 cup dark brown sugar

1/2 cup golden syrup

2 oz unsalted butter, melted and cooled

1/2 teaspoon salt

1 teaspoon vanilla

1 cup grated apple

1 cup autumn olive puree

Whisk everything but the fruit until the mixture is smooth. Carefully stir in the apples and autumn olive. Pour it into the pastry shell and bake at 350 degrees F. for 45 minutes.

Submissions for the Biodiversity Corner are encouraged from everyone. What are you finding? Send a note to Kay Fairweather at 392 School Street, Carlisle MA 01741 or e-mail her at

All Photos by Kay Fairweather

2007 The Carlisle Mosquito