With charter schools expanding at a record pace in New York, recruitment efforts are also ramping up, and the clearest sign may be in the takeout deliveries.

Along with dinner, the owner of La Familia, a Mexican restaurant on Gun Hill Road in the Bronx, has recently been delivering customers bright orange fliers announcing, in English and Spanish, the brand-new Bronx Community Charter School, which opens in September.

“We gave him a stack of fliers, and every time someone ordered takeout, he gave them one,” the school’s co-director, Sasha Wilson, said.

In anticipation of tomorrow’s application deadline, video stores, bakeries, and churches have also passed out fliers, Mr. Wilson said. Applications will be sorted out by lottery on Thursday.

The campaign-like outreach is an annual ritual for charter school leaders, who, unlike the principals of traditional public schools, cannot simply count on students to show up. Because they operate outside regular district regulations, they must recruit them.

Other charter schools have been canvassing on a scale similar to Bronx Community Charter School’s, sending teams of teachers and parents door to door, handing out fliers at subway stations, and even in some cases buying ads at bus stops.

Mail — glossy brochures inviting parents to “Apply today” — is also piling up, thanks to new help from the city’s education department, which has opened up its address book of all public school students. (To protect privacy, charter schools do not have direct access to the addresses but work through a mailing house contractor instead, and they must cover their own bills.)

The ritual is accelerating this year.

One reason is growth. After new legislation last spring doubled the state cap on the number of charter schools allowed to operate, about 15 charter schools are expected to open this September — the most charter schools the city has ever seen open in a single year, according to the Education Department’s executive director of charter schools, Michael Duffy.

The recruitment also represents a concerted effort by charter school leaders and supporters to counter a criticism often levied against them, the idea that they “cream” the best students from traditional public schools.

A study of city charter schools led by a Harvard economist, Caroline Hoxby, last year concluded that the schools enroll slightly fewer special education students than traditional public schools and found they had far fewer English-language learners, 4% versus 14%. The same legislation that raised the charter school cap included a mandate that school leaders “make best efforts” to recruit special education students and English language learners.

Mr. Wilson of Bronx Community, who is fluent in Spanish and lives in the neighborhood where his school is opening, said he reached out not only to La Familia but several other local businesses that cater to Spanish speakers. He said he also reached out to special education groups, including a city office that counsels parents of preschool-age special education students to help them make the transition to kindergarten.

Mr. Duffy said the new mailing arrangement was also intended to help charter schools expand their outreach.

Mr. Wilson said it helped him expand his list of first grade applicants to 150 from 25.

The CEO of Harlem Success Academy, Eva Moskowitz, who is opening three new schools next school year, applauded the new mailing service but dismissed the “creaming” idea as a myth, noting that 23% of Harlem Success students are special needs, a higher proportion than the city average. At the Achievement First charter schools, underserved students are the “target audience,” the schools’ director of external relations, Lesley Esters Redwine, said. In addition to using the Department of Education’s database, Ms. Redwine said Achievement First contracted with a private mailing service to target 1,500 fliers to families whose incomes do not exceed $30,000.

“That’s the parent who I want to serve,” she said.