The Hampton Gardener: Mushrooms

As a result of all the moisture we had this summer we are seeing a bumper crop of mushrooms in the landscape and in the woods. These are not the pasty white or dirty brown ones that you buy in the supermarket, but the ones that grow in your backyard, lawn, in the woods and in other places dark and damp.

In fact it’s been a remarkable summer for mushrooms. If you’re looking, you’re sure to see some typical Slippery Jacks, an occasional edible Bolete or a Parasol and one type will even look like a lobster claw reaching out of the trail in the woods with its perfect coloration. As we get on toward October there will be even more—some black ones, some orange and red—and it may seem that there’s a mushroom for every color, but hunter beware!

Not being much of a mushroom eater, I haven’t been tempted to do any collecting, however, each year people are poisoned by what they think are “safe” mushrooms. Even the experts are extremely careful when collecting wild fungi and even when well cooked the poisonous ones retain their toxicity.

In July, a woman working at a rest stop on Interstate 84 in Westchester saw a patch of seemingly safe small white mushrooms and she harvested and ate 10 to 15 of them. Apparently they looked just like the white button types you might find in the supermarket, but four days later she was dead.

There is also a situation in lawns where a mushroom population can become established and cause serious damage to the turf. This condition is referred to as fairy rings in which the fungi stimulate rings of fast growing lush green turf followed by rings of dead and failing turf. Mushrooms in the form of puffballs or toadstools may be obvious and can be a problem if you’ve got young children who may be tempted to eat them. You can get more information on this phenomenon at http://plantclinic.cornell.edu/FactSheets/fairyring/fairyring.htm including pictures and control measures.

The rule of thumb is to limit your ‘shroom hunting to the supermarket

where your decisions will be limited to picking only those that are treated to retard spoilage or those that are untreated, but still safe to eat. And yes, the kits that you can purchase in garden centers and though catalogs do produce real, tasty mushrooms and kids will enjoy the kits as great indoor projects. (See the end of this column for local mycological society contacts.)

While some of the culinary romance (and risk) may be eliminated in the supermarket varieties, there is an interesting story behind the great American mushroom. Last year, more than 900 million pounds of mushrooms were produced by American growers. This is an increase of 500 million pounds in less than 10 years and yet, the price that a mushroom farmer gets per pound has basically remained the same, a story familiar to many farmers. New growing techniques, however, have increased profit margins and Pennsylvania areas long known for their mushroom farms have seen an influx of new capital from private investors as well as large agribusinesses. There is now even a booming export business in mushrooms, as it seems to be a commodity that we do a better job at than the Japanese who are devouring tons of our fungi.

Despite their fondness for dark places, mushrooms have never been a very humble vegetable; mushrooms and magic have been synonymous since the beginning of history. The Egyptian pharaohs, for instance, reserved mushrooms for their own plates and forbade commoners from indulging. The Romans, believing mushrooms gave their warriors extraordinary strength in battle, passed similar laws and called them the “food of the gods.” Until the 18th century in France, however, when something like modern mushroom growing techniques began in limestone quarries outside Paris, cultivated mushrooms were unknown.

Today, of the 38,000 varieties of mushrooms, only a handful are grown commercially in this country, the most popular being

Agaricus bisporus

. They are grown in either underground caverns or in windowless “black houses,” which look much like our nearly extinct East End potato barns. The newer ones that I saw several years ago were like concrete bunkers some 40 feet wide and up to 100 feet long with racks of growing beds from floor to ceiling. These houses are kept totally dark while production is in progress and they must be kept on the cool side, which for many years limited production to the winter months.

Fortunately for you mushroom lovers, these strange farms now run year-round, but as where a bedding plant or greenhouse grower incurs most of the growing costs in the winter months when the greenhouse must be heated, the mushroom grower incurs most of his costs in the summer when he must air condition his facilities.

The growing process begins in a laboratory because sterile conditions are required to begin the growing cycle. The spores, or natural seeds of the mushroom, are so infinitesimal that they cannot be handled by the farmer. Laboratory personnel must inoculate cereal grains with them and incubate them until viable product is developed. These grains become “spawn,” which can then be sown like seed in the long dark beds. The growing beds were once filled with partially decomposed cow manure, which became the standard growing media. Most people think that this is the way it is still done and you can hear horror stories about trips to the mushroom farm, “but the smell...” Now, however, the farmers can no longer get inexpensive cow pie compost and they have a new scientific formula that is odorless.

From the point of spawn to harvest takes about a month. During the harvest, mushrooms mature at varying times and so picking has to be continual for two to three months. Once a bed is finished, it must be completely emptied and the entire house sterilized before a new crop can be moved in.

You may be able to find supermarket mushrooms in three colors: white, brown or cream. The white type was discovered by a Pennsylvania farmer in 1926 and is the most popular variety on the East Coast. Brown mushrooms, sometimes called California browns, have dominated on the West Coast and the creams for some strange reason are found in between.

When shopping for cultivated mushrooms, look for firm, smooth ones with the veil—the membrane between the cap and the stem—still attached to the cap. Many people get upset when they go to buy white mushrooms because they see only brown ones or browning ones. These are not California ‘shrooms, but local varieties that have been exposed to the air and light causing oxidation and the change in color. This is not an indication of poor quality, but may indicate freshness. Beware though because many pre-packed mushrooms are treated with an oxidation retardant that eliminates the browning and your ability to judge freshness. Mushrooms with veils intact will normally keep in a refrigerator for a week.

Weight watchers can pig out. A pound of mushrooms (less the stuffing of seafood, meat, spices and other delicacies) will add only 125 calories to your diet. They are fat free, low in salt and an excellent source of protein.

For those of you interested in learning more about collecting and identifying wild mushrooms, there are a number of very active mycology societies in Manhattan, Westchester, Connecticut and on Long Island. These groups support many field trips for newcomers as well as neophyte collectors and their outings run from spring through early December. For additional information please visit the NY Mycological Society’s web site at www.newyorkmyc.org/nymsfusion/news.php.

Keep growing, even if it’s in the dark.

Andrew Messinger has been a professional horticulturist for more than 30 years. He divides his time between homes and gardens in Southampton, Westchester and the Catskills. E-mail him at: Andrew@hamptongardener.com. The Hampton Gardener is a registered trademark.