UNLESS you have a thing for groundhogs, the appearance of asparagus at the farmers' market is the most reliable indicator that spring has arrived.
The soil needs to reach a temperature of at least 50 degrees in order for these tender shoots to grow. That's why this perennial thrives in a warmer climate like that of the Delta, where the nation's tastiest asparagus is grown.
"The Delta should really be designated an asparagus appellation, or specific growing region," says Roscoe Zuckerman of Zuckerman Farms. "The soil and climate there produce plants with a flavor far superior to those grown in other areas."
Most commercially grown, early-season asparagus comes from Mexico or the Imperial Valley where, Zuckerman says, the lack of water in the soil and harsh climate result in tough, stringy, strong-tasting spears.
Most out of season asparagus is imported from Peru and Chile. This asparagus is inferior in flavor because the rigors of shipping, handling and age. Because agricultural chemical applications are not as regulated in developing nations, the asparagus may be sprayed with a variety of pesticides, some of which may be banned for use in the United States. Not only do these chemicals have a negative impact on the environment, they can also affect the farm workers who come into contact with them.
Zuckerman, like many commercial asparagus growers, practices I.P.M., or integrated pest management, on his Stockton farm. I.P.M. uses a variety of strategies to prevent infestation, including the use of beneficial insects to eat pests and their eggs, and weather monitoring. Although I.P.M. may still rely on the use of some synthetic chemicals, it is usually only after other methods have failed.
"Unless a pest such as asparagus aphid or cutworm is really economically threatening to our crop, we don't spray our plants," says Zuckerman. "The aphid actually attacks the fern that shoots up after the plant has gone to seed, so even if we do spray, the spears have already been harvested for the season."
In an industry that routinely uses chemicals prophylactically, it is encouraging that a number of domestic commercial asparagus growers take a different tactic. Some organic farmers prevent infestation by using chickens and ducks to eat beetles and worms and their larvae.
Organic farmer Jim Durst, of Durst Farming in Yolo County, has his own approach to growing asparagus. "You're more prone to develop pest problems with large blocks of crops, so we surround our asparagus with other crops such as alfalfa, to encourage a habitat for beneficial insects. We're also isolated enough from the major asparagus growing regions that specific target pests aren't a problem."
Asparagus plants produce only a few spears per harvest, but their perennial nature means that the same plant can produce spears during the late February to May harvest season for up to eight years.
The mature roots, called "crowns," require a looser soil to allow the spears to grow straight, then the spears are cut off just below ground level at harvest.
Durst prefers to keep mounds of dirt fluffed up on top of the beds, to keep the woody, inedible butt ends of the spears lower down in the soil and render more of the spear edible. Judith Redmond of Full Belly Farm mulches her asparagus with hay to retain moisture in the soil.
"Asparagus is a really low maintenance crop to grow, but it's high maintenance to harvest," says Durst. "Each spear is handled up to five times before it goes to market, so there's a lot of labor involved, especially with organic crops. That's why it costs more."
Purple "Viola" asparagus has a particularly high sugar content, but the dark hue fades with cooking. White asparagus, a costly delicacy especially popular in parts of Europe, is grown by placing dark plastic or dirt over the developing shoots in order to deprive them of sunlight and keep them from making chlorophyll.
There is great culinary debate over whether pencil-thin or fat stalks taste better. Durst favors the fatter stalks, which have a higher sugar content. Redmond also notes that the larger stalks command a premium price at the market.
While I find the slender spears more aesthetically pleasing, the flavor tends to be more herbaceous and grassy. The mature stalks are sweeter and more succulent.
"We use different sizes for different things," says Paul Canales, chef de cuisine at Oliveto in Oakland. "The fat stalks have that well-developed sweetness, and are great cooked to order with salmon or paired with a tuna confit. They have a more substantial feel that can stand up to the heaviness of certain sauces or food combinations. The thin stalks are wonderful for grilling and serving Florentine-style with a little bit of pancetta and chopped, hard-boiled egg."
I love Terra Firma Farm's sweet purple asparagus simply steamed with a little butter and Parmesan, and I just roasted some fat, juicy spears of green asparagus from Kaki Farms with a little extra virgin olive oil, salt and pepper. I sliced them thinly and tossed them with some fresh spinach fettuccine and goat cheese. Delicious.
"Asparagus is just so forgiving, as long as it's not overcooked you can do anything to it," says Donald Dellis, chef-owner of Oakland's Grasshopper. Dellis serves asparagus grilled and dressed with a soy and shallot vinaigrette.
Regardless of what size spears you buy, avoid purchasing asparagus that has dried or separated tips or butt-ends, a sign of age. Be aware that the more mature stalks can be tough and woody, especially if they've been shipped long distances. Durst points out that while you may pay only 99 cents a pound for imported or some commercial domestic asparagus, "it's so old and dried out that you end up throwing a third of it away!"
Like corn, the natural sugars in asparagus start converting to starch as soon as it's picked, so try to eat it right away. You can store it in a plastic bag in your refrigerator for a day or two, or place the stalks upright in a jar of water to prevent moisture loss.
Whatever you do with it, get your fix now because the season is fleeting, just like that elusive groundhog.
Full Belly Farm's asparagus is available at the Berkeley and Palo Alto farmers' markets; Kaki Farm's asparagus is at the Berkeley and San Mateo farmers' markets; Terra Firma Farm's is at the Berkeley and Marin farmers' markets; Zuckerman Farm's is at the S.F. Ferry Plaza, Grand Lake, Menlo Park and Danville farmers' markets; and asparagus from Durst Farming is at Whole Foods, Lunardi's, Rainbow and New Leaf markets.
ASPARAGUS AND BUTTERMILK SOUP
Recipe published by "Cooking Fresh from the Bay Area" (Eating Fresh Guides, $17.95), created by David Kinch, chef/owner of Restaurant Sent Sovi in Saratoga.
1 medium onion, sliced fine
2 peeled shallots, sliced fine
2 cloves garlic, crushed
1 medium potato, sliced fine
6 tablespoons unsalted butter
11/4 pounds asparagus, trimmed of white roots and sliced thick (reserve some of the tips to be blanched and used for garnish)
Salt and pepper
Buttermilk, about 1/4 cup
In a nonreactive pot, place onions, shallots, garlic, potato, butter and enough water to just cover the vegetables. Bring to a simmer and stir occasionally until potatoes are soft. If water evaporates during simmering, add a bit more to cover.
Add asparagus to the pot and enough water to just cover the vegetables. Bring to a boil, stirring so nothing sticks. When asparagus is soft but still slightly crunchy, puree as quickly as possible with a food mill, food processor or blender. Moving quickly will ensure a bright green color and fresh asparagus flavor.
Pour pureed soup into a stainless steel bowl and place that bowl into a larger bowl filled with ice. Chill thoroughly. Season with salt and pepper to taste. Gradually add buttermilk to taste, using enough to give the soup a dose of acidity but not enough to overpower the asparagus flavor. Serve chilled, with chives and blanched asparagus tips. Serves 6.
Per Serving: 144 Calories; 12g Fat; 2g Protein; 9g Carbohydrate; 2g Dietary Fiber; 31mg Cholesterol; 131mg Sodium. Exchanges: 1 Vegetable; 21/2 Fat.
E-mail Laurel Miller at email@example.com.
This column is a service of the Berkeley Farmers' Market and Eating Fresh Publications (www.eatingfresh.com) publishers of "Cooking Fresh from the Bay Area."
The Berkeley Farmers' Market is open 2-7 p.m. Tuesdays at Derby Street and MLK
Jr. Way, and 10 a.m.-3 p.m. Saturdays at Center Street and MLK Jr. Way.
Call (510) 548-3333 or visit www.ecologycenter.org