Blueberries have started to show up in the stores and at local farmers markets. That's a sure sign to me that it's time to get prepared for summer vacation up north, and an opportunity to head out into the fields to go berry picking.

Clear out your freezer to make way for this year's crop; here's some local U-pick information plus suggestions if you're heading north.

U-pick

On a good day, someone who is skilled at picking blueberries can fill a one gallon container weighing five pounds in an hour. It's always good to call ahead if you are looking to pick berries in quantity, because yields will vary by season and how much picking has been done in the days before.

Dexter Blueberry Farm on Beach Road in Dexter is expected to open on Monday, July 12. Call (734) 426-2900 for current conditions. The farm has an e-mail list to notify pickers of current conditions.

The Blueberry Patch is in Grass Lake, just west of Chelsea in Jackson County. I called this morning, and was told that the berries would be ready in about a week and a half (which puts it at about July 15). They have 3 acres of organic berries, covered with nets to keep the birds off the bushes. Call (517) 522-4796 for current conditions.

Cultivated blueberry crops in Michigan

The Michigan State University Blueberry Team directs the blueberry extension effort in Michigan. The team publishes a weekly Michigan Blueberry Newsletter, with news for the industry about disease management, growing weather and any issues of the week relevant to industry professionals. Most of the commercial blueberry cultivation is in the southwest corner of the state, with the Van Buren County MSU Extension Blueberry Web also offering detailed information.

The latest issue online as I write this is the June 29, 2010, edition of a week ago. At that time, the crop report noted that fruit is ripening about 7 to 10 days ahead of normal:

In Van Buren County, Jersey blueberries in Covert are at the coloring stage, and f and Bluecrop and Blueray berries in Grand Junction are about seven to 10 days from first harvest. In Ottawa County, Blueray in Holland, and Rubel and Bluecrop in West Olive are at fruit coloring.

Blueberry price reports

The price of wholesale frozen blueberries depends quite a bit on how much of last year's crop is still in cold storage. Price supports for the berry industry involve purchases of frozen fruit for use in federal food assistance programs like school lunches.

The Capital Press, an agricultural news service that serves the Northwest, reported in April 2010 that blueberry prices were rising as stocks declined.

At less than 108 million pounds in early March, stocks were 18 percent lower than at the same point last year.The drop in frozen supplies has been reflected in wholesale prices, said Rod Cook, an agricultural consultant. During last summer's harvest, frozen blueberries were selling for about $0.65 to $0.75 per pound at the wholesale level, Cook said. Since then, there's been a solid increase of about $0.20 per pound, he said.

The United States Highbush Blueberry Council Web site has information for the industry. Note that you and I are unlikely to have a home freezer suitable for storing wholesale quantities of fruit.

Wild blueberries up north and the Kirtland's warbler

Wild lowbush blueberries grow in the northern parts of the state, including the jack pine forests of the northern Lower Peninsula and the sandy plains of the Upper Peninsula. Paradise has a Paradise Wild Blueberry Festival Aug. 20-22 of 2010. The Hunt's Guide recommends picking at the old missile base near Raco, Mich.. There's also good picking near Grand Marais,, though you might be fighting a variety of biting insects which leave blueberry-sized bites.

Federal forest management for the endangered Kirtland's warbler has the side effect of preserving wild blueberry habitat. In Managing the forest for the Kirtland's warbler, the US Fish and Wildlife Service notes:

The Kirtland's warbler nests only in young jack pine forests growing on a special type of sandy soil. This type of soil is found only in a few counties in Michigan. The warblers prefer to nest in forests that are about 80 acres (roughly 60 football fields) or larger with numerous small, grassy openings. Kirtland's warblers prefer to nest in groups. They build their nests only on the ground among grass or other plants like blueberry bushes.

Wild blueberry plants do not yield a crop every year, so the alert berry picker will have a series of locations to chose from and will be willing to provide imprecise directions to a good patch to friends and family.

Edward Vielmetti picks blueberries for AnnArbor.com.