The Lorton Community Action Center in Fairfax County is looking for school supplies, CrisisLink in Arlington County and Carpenter's Shelter in Alexandria are scrambling for volunteers, and the Loudoun Interfaith Relief food pantry just ran out of canned fruit.

It's summertime, and the living isn't easy for area nonprofit groups.

With the holiday charitable-giving binge long over and donors and loyal volunteers away on vacation, charities often find themselves struggling to get by at this time of year. Donations dip, volunteers disappear and, at the same time, charities face sharply increased demand for some services.

"It is a time of year when we need to remind people that, for a lot of folks, there is need all year around," said Kerrie Wilson, executive director of Reston Interfaith. The group, which offers a range of services to the poor -- including a homeless shelter, social services and food programs -- regularly scrapes for donations at this time of year.

Especially hard hit are food pantries and food banks because more poor families turn to charity groups to fill out their cupboards during the summer months. Directors of nonprofit agencies say that's mostly because low-income children generally don't receive the free- or reduced-priced breakfasts and lunches that they get during the school year.

But food donations fall sharply at this time of year because fewer food drives are conducted by the groups' regular supporters -- religious organizations, Scout troops and schools.

Food for Others in Fairfax is one of those that sees its canned food donations fall dramatically during the summer, said Executive Director Roxanne Rice. Last August, for example, the group collected a mere 740 pounds of canned food from food drives, compared with 64,000 pounds in November, when the Thanksgiving and Christmas holidays encourage people to think about the needs of others.

To get by during the lean summer months, Rice said, the group relies on fresh fruit and vegetables donated by grocery stores, area farmers markets and the U.S. Department of Agriculture's research fields in Beltsville.

"If we didn't have the produce coming in, we would be in trouble," Rice said.

Some shelters for the homeless also see a jump in the number of people in the summer.

SERVE, a Prince William group that operates a Manassas shelter, says its 56-bed facility is fuller in August than in December -- partly because families who have had difficulty finding a home decide to settle into the homeless shelter in late summer so their children will have a relatively stable place to stay before school starts. SERVE Executive Director Lindy Garnette also said relatives are more apt to take in homeless family members during the winter holiday season, less so in the warm summer months.

Groups that offer respite care to those who care for aged relatives or disabled children struggle at this time of the year as well.

At Northern Virginia Family Service, requests for short-term respite care for emotionally and physically disabled children climb 65 percent in the summer, said Erin Mahoney, the group's director of community relations. In fall and winter, caregivers can get time to themselves when the children are in school, but in the summer they turn to other caregivers to provide some weekend respite.

School vacations also cause hardship for groups that rely on volunteers whose schedules revolve around the academic year.

During the school year, for example, at-home moms are the backbone of the volunteer staff at the front desk of Carpenter's Shelter, the Alexandria homeless shelter. But during the summer, those volunteers are at home with children, and the shelter has a hard time finding replacements, Executive Director Fran Becker said.

It's also an annual summertime scramble for CrisisLink, which runs 24-hour suicide-prevention and crisis hotlines and education programs. Many of CrisisLink's volunteers are students or young working professionals who leave town or move during the summer. And because the program requires an intensive 45-hour training program, "when we lose people, we can't replace them easily," said Executive Director Carol Loftur-Thun.

As a result, she said, CrisisLink is using staff members to cover some shifts normally covered by volunteers.

In addition, many nonprofit groups that assist children are gearing up for the school year during the summer months.

The Lorton Community Action Center, which offers food, clothing and other services to low-income residents of southern Fairfax, is seeking donations of school supplies -- such as pencils, pens, backpacks and binders -- to outfit about 200 children for the school year. Conducting a school-supply drive in the summer is challenging, said Linda Patterson, the group's director of emergency services. But, she said, "the economy hasn't gotten any better regardless of what politicians say. We're still seeing a huge impact on our families."

At the Food for Others warehouse Monday, Rosie Green tidies up what is left on the shelves of the Fairfax food bank, where donations fall in summer.Volunteer Jonathan Frame sorts through corn at Food for Others' warehouse. Area food banks must fill needs as support drops off.