When it's time for Chanell Carver's two daughters to head back to Green Holly Elementary for the first day of school next week, there probably will be few of the usual parental headaches.

No ransacking the closets in search of backpacks, no last-minute rush for supplies, no challenge in rousing Shaniah, 7, and Shyann, 5, from a deep summer slumber.

"I don't have to worry about saying, 'Come on! Get up! Get going!' They're already on their school schedule," Carver said.

After all, they've been out of school for only a week. Carver's daughters are among 160 students who took part in an 11-month school year experiment in St. Mary's County. After about five weeks off in early summer, selected students from three elementary schools returned in late July for a month of additional classes at Green Holly in Lexington Park.

The pilot program is just one of the changes that Southern Maryland educators are discussing as another school year begins. Classes resumed Tuesday in Calvert public schools. St. Mary's and Charles schools are scheduled to open Monday.

The summer session at Green Holly focused on reading and math skills in classes of about 10 students. Students also learned about other cultures by studying the Olympics.

"We found that [other summer programs] weren't intensive enough," said St. Mary's School Superintendent Patricia M. Richardson. "Our hope is that this will not only prevent students from losing ground over the summer, but we will actually give them a head start."

For school systems in all three Southern Maryland counties, continuing growth has added hundreds of students, and educators said accommodating the large enrollments would be among the top challenges this year.

St. Mary's estimated that 207 new students would attend this year, bringing total enrollment to 16,283. Calvert projected an increase of 423 students, for an enrollment of 17,553. Charles's enrollment will grow the most, officials said, adding a projected 869 students, for a student population of 25,512. Official student counts are reported at the end of September.

"The single biggest issue [in Charles County] is not having enough schools," said Superintendent James E. Richmond.

As the school year begins, 21 of 31 Charles County schools, including all five high schools, have more students than their state-rated capacities, officials said. The system relies on 177 movable classrooms to help handle the overflow. In St. Mary's, eight of 23 schools are projected to be above capacity. In Calvert, 11 of 21 schools are overcrowded, according to figures from last year.

Richmond said construction of schools would help alleviate the crowding in Charles. North Point High School for Science, Technology and Industry in western Waldorf is under construction and scheduled to open in August 2005. In addition, groundbreaking for an elementary school is scheduled for Sept. 9, and Charles hopes to receive state funding commitments this year for a new middle school that could open in August 2007.

Among the changes in Charles this year, Richmond noted that the county is testing a program to prepare 3-year-old children for elementary school. The voluntary program will be housed at Mount Hope-Nanjemoy and Gale-Bailey elementary schools, he said.

"If we can eliminate some of the major reasons why kids are behind from the very beginning . . . we can solve some problems right away," he said.

In St. Mary's, besides the 11-month schooling program, Richardson said the school system is implementing a reading series for students from kindergarten to sixth grade that is closely aligned with state curriculum standards. As all systems face increasing pressure to succeed on standardized tests, Richardson said, younger students would switch to textbooks tailored to the requirements of Maryland's voluntary curriculum.

Richardson said the biggest challenge in St. Mary's this year is finding locations for three elementary schools in the county's long-term construction plan. Sites in the Leonardtown, Hollywood and Wildewood areas have been considered, but nothing has been finalized, Richardson said.

"We need them now; they're critical," she said. "But what is holding us back is our inability to secure a site that we can submit to the state for approval."

For Calvert County, the most significant changes will be seen at the high school level with the opening this week of Huntingtown High School. Freshmen met Monday at the county's fourth high school, and classes resumed for all grades on Tuesday.

"All three of our high schools were just so crowded, it's going to provide some much-needed relief to all of them," said Calvert Superintendent J. Kenneth Horsmon.

The building is ready for students, but some sports fields have not been completed, he said. Huntingtown field hockey and soccer teams are practicing elsewhere, and Horsmon predicted work would continue on the fields for up to a year.

"The weather has just been real tough on school construction," he said. "It won't stop raining."

Beyond getting accustomed to the Huntingtown school, Richmond said, a major focus of the school year will be preparing students for the standardized high school assessment tests that ninth-graders will take next spring. Passing the assessment tests will be a graduation requirement for high school students. The system is in the second year of a pilot program that allows some ninth-graders to take most of their classes together in the same small groups.

"We think having those smaller numbers, personalized service for students and outreach for parents, is going to be really helpful," said Carol Reid, Calvert's assistant superintendent for instruction.

The Calvert system also will unveil an alternative education program, based at Calvert High School, designed to provide an intimate learning environment for struggling students. The program will serve up to 20 students from grades 6 through 12 who have "difficulty functioning in a traditional school setting," said Deborah Pulley, the director of secondary education in Calvert. The county has allocated three teachers and two instructional assistants to run the all-day classes. Students in the program will be evaluated continually and returned to regular classes when they show sufficient progress, she said.

"This represents an alternative to extended suspensions or expulsions," she said.

Meanwhile in Calvert, contract negotiations between the Board of Education and the teachers union are still at an impasse. The board and union officials have each chosen arbitrators to jump-start the negotiations, and a third independent arbitrator is being selected. If no agreement is reached, Horsmon said, the board could impose salary terms on the teachers for one year.

"I'm always hopeful we'll reach an agreement. . . . It's better to reach one than impose one," he said. "This has not been a typical summer for me at all with the negotiations. I'm hoping we can get that behind us and move on."

Kelly Jensen, a fourth-grader at Sunderland Elementary School in Calvert County, waits to get off the bus before the start of classes Tuesday. Mellissa Gray sends her daughter Julia, 5, off for her first day of kindergarten in Sunderland. Schools in St. Mary's and Charles counties open Monday.A Sunderland student receives a reminder about which bus to ride. Enrollment in Calvert County was expected to rise by 423 students.