The Carlisle Mosquito Online

Friday, February 11, 2005


Black Walnut

Next Monday is Valentine's Day and I wanted to find an appropriate nature topic. Many of the likely suspects, like the wild rose or the forget-me-not, cannot be verified this time of year. A critter that could worm its way into your heart, the heartworm, doesn't conjure up the right image. The chocolate tube slime mold has the right idea by starting out with chocolate, but like others I have known who started this way, it becomes self-absorbed and distracted by other urges. So I chose the black walnut, Juglans nigra, with its beautiful and well-protected secret heart. There are some mature trees along the north side of Curve Street not far from Lowell Street. While the black walnut is native to the eastern U.S., these particular ones may have been planted there long ago. You can also find them alongside some roads in Concord.

The heart of the matter: To find the hidden heart inside the nut you have to carefully crack it longitudinally along the line where the two halves come together. If you strike it right, you will find two perfect hearts within hearts. Carelessness with the nuts or any form of rough treatment will surely result in (at least) a broken heart — and that's as far as I can go with this train of thought.

Labor of love: To husk, shell, and pick the sweet meats out of black walnuts and make a gift to your honey is one of the top ten signs of true love. Fuggedabout gift wrapping — this is all about unwrapping. You want the seed, within the nut, within the fruit. First, you have to remove the fleshy outer husks of the greenish-yellow, spherical fruits. It's a messy task. If you use your hands, wear rubber gloves to protect your skin from staining. Or you can put on your Wellingtons and stomp the husks off with your feet. Fuggedabout the tango — do the Juglans jig — the dance of love. The next step is to remove the hard, blackish, ridged, thick-walled nutshell that is protecting the seed, but wait at least a week to allow the nuts to dry. Leave them on newspaper or something that you are not concerned about getting stained. You can keep the nuts in this state until you are ready to use them — I have kept some for a year with no harm done. The shells are very strong. I use a tomahawk and then a heavy-duty nutcracker. A lobster pick is helpful in getting out every last piece of meat.

Taste: Fresh black walnuts have a rich, earthy, smoky flavor. They are oily and aromatic. The "wildman" Steve Brill has many recipes using black walnuts in his Wild Vegetarian Cookbook (in the Gleason Library). Bonnie and Gabor Miskolczy, who introduced me to the delights of black walnuts, once found and enjoyed black walnut ice cream by Hagen Daaz. For a romantic evening by the fire, fuggedabout the classic combination of port and Stilton; try some freshly hulled black walnuts with a bottle of 1970 Graham's vintage port.

Toxicity: Various parts of the black walnut are known to be moderately toxic to horses and dogs. Make sure your dogs don't get access to the newly fallen fruits in the fall, or to the husks after your Juglans jig. Horses can develop respiratory ailments from pollen and fallen leaves if there are black walnut trees in the horse pasture. They can also get laminitis (a hoof disease) from contact with or consumption of black walnut wood shavings which are sometimes used in horse bedding. The black walnut exudes a substance, juglone, which is toxic to other plants and keeps them from growing too close.

Distinguishing characteristics: The black walnut tree has dark brown ridged bark and compound leaves each with 9 to 21 leaflets. The main rib of the leaf is one to two feet long. The tree can most easily be recognized by the fruit when it drops in the fall. The fruit is one and a half to two and half inches in diameter. A dog might see it as a small tennis ball. Any fruit not gathered by humans will be taken by squirrels and other wildlife.

References: Steve Brill, Wild Vegetarian Cookbook; Elbert L Little, The Audubon Society Field Guide to North American Trees; Purdue University School of Veterinary Medicine at

2005 The Carlisle Mosquito