Lisa Cain shows her 6-year-old daughter, Lillian, how to use a Phillips screwdriver in their home in the District. Cain began home-schooling her two children last month. (Erin Schaff/For The Washington Post)

When Lisa Cain’s second-grade son became bored at his charter school in the District last year, she started searching for a new school. She went to public schools — “about 25 open houses,” she said — and visited a handful of private ones, too. At the same time, she pored over education research and theory.

“The more I learned about education, the more I found that kids learn by being excited about the subject and taking it upon themselves to learn. Not, ‘Okay, now we are going to do this,’ ” she said. She decided that private schools are too expensive and that her concerns about large class sizes and test-driven curriculum would not disappear at another public school.

Ultimately, she opted to home-school her son and first-grade daughter.

In a city known for its ever-growing array of school choices, small but growing numbers of parents are opting to chart their own course. The number of registered home-schooling families grew by a third over the past two years to nearly 400 this fall, up from about 290 in the 2013-2014 school year.

The growth has brought an increase in the number of home-school cooperatives and Internet mailing lists that offer support, structure and community for families. Classical Conversations, a Capitol Hill-based home-schooling “community” with a Christian focus, started two new groups this year, one in Brookland and the other in Capitol Hill. “We got so many inquiries last year, we had to turn people away,” said Emily Bradley, who directs the Capitol Hill group.

Lisa Cain colors with her children Sam, 8, and Lillian, 6, in their home in the District. (Erin Schaff/For The Washington Post)

Thirty years ago, there were few legal protections for home-schoolers. But the number has grown as state regulations have eased or have been formulated. Nationwide, about 3 percent of the school-age population was home-schooled in the 2011-2012 school year, according to the most recent data from the Education Department.

The District did not have a specific law for home-schooling until 2008, when Banita Jacks, who had claimed to be home-schooling her children, was arrested in the killing of her four daughters. Their bodies were not discovered for months, and the case raised alarms about a wide range of breakdowns in the safety net for children in the city. Jacks was convicted in 2009 of murdering her four daughters.

That year, the D.C. State Board of Education approved a policy that requires parents to give written notice to the Office of the State Superintendent if they want to home-school and to maintain a portfolio of student work that is available for the state agency to review.

Ethan Reedy, a father of three and president of the D.C. Home Educators Association, said home-school parents in the District make up a very diverse group.

“We have both ends of the political spectrum and all sorts of worldviews,” he said.

Groups have formed for African Americans, Christians, gifted students, military families or for those who have progressive views on education. “There are quite a few ‘unschoolers’ in the District who think of schooling as much more of an adventure than a rigorous educational institution,” Reedy said.

Home-schooled student Sam Yang, 8, unscrews the front of a speaker to see how it works as part of an experiential learning project with his mother and sister at home in the District. (Erin Schaff/For The Washington Post)

Many home-school parents say the District offers one of the nation’s best classrooms, with its extensive natural and cultural resources.

“It’s the land of free museums and free programs,” said Farrar Williams, who home-schools her sixth-grade twins in Columbia Heights. She said many arts organizations or taekwondo gyms offer classes for home-schoolers.

When she started out seven years ago, there were few other families in the city home schooling, so she often joined with families in Montgomery County or in Alexandria. Now there are more resources in the District, she said, in particular for younger children.

Lisa Cain said venturing out on her own was scary. “There were definitely waking-up-in-the-­middle-of-the-night moments, thinking, ‘Is this the right thing?’ ”

The Mount Pleasant mother formed a co-op with some other families. They meet together four days a week and take turns leading optional field trips on a fifth day. That allows her to continue working part time in public relations and party planning, she said.

At home, and through the ­co-op, her two children are learning at their own pace and pursuing their interests. They spend a lot of time in Rock Creek Park, she said, and in their vegetable garden. Her first-grade daughter’s love of birds led to lots of reading about birds and a trip to the zoo, where they learned about different ways to attract birds. Her husband, an IT network engineer, likes to tinker with electronics and explore robotics with them.

So far, a month into the new school year, she has noticed a change in her son. “He is excited and talking about what he’s doing during the day,” she said of the third-grader. She also noticed a difference in the stress level at home without homework battles and a hectic rush-hour commute to school.

“My surprise, so far, is how natural and how much easier it is,” she said. “We are all natural learners, and learning doesn’t just happen at school. It happens everywhere.”