Kindergartner Isabella Bjornson and her mother, Jo Ann, attend a school ice-cream social at Madison Manor Park in Arlington, Va. on Sept. 9. (J. Lawler Duggan/For The Washington Post)

Jo Ann Bjornson spent her early childhood in the care of babysitters until it came time for her to board the bus to school for half-day classes, an event that came with little fanfare. For her daughter Isabella, the days before kindergarten started this month included structured preschool, a bevy of summer camps and months of agonizing over whether the smart, sensitive 5-year-old was academically and socially ready to start school.

Kindergarten, where children were once encouraged to play and adjust to the rhythms of the school day, has long been evolving. But many parents new to modern-day elementary schooling say they have been shocked to find their children in a pressure cooker of rigorous academics, standardized tests, homework and what seem like outrageous expectations.

The nation’s earliest grade — if you don’t count pre-K — now comes with packed orientation nights, school tours, Twitter chats, warnings to make sure children brush up on their skills and “dress rehearsals.” Some parents have come to view the first year of school not as a transition but as a make-or-break gauntlet that will shape their child’s academic career.

Many worry that their children are ill prepared for the more strenuous environment, that their kids, not far removed from their toddler days, will burn out.

“What if I make the wrong decision and I send her too early?” said Bjornson, of Arlington, a vice president of human resources at Leidos. “I don’t want to screw my kid up for forever. Am I going to set her up for failure for the rest of her life?”

New research from the University of Virginia published this year confirmed the shift parents have been feeling: Kindergarten has grown far more academic, with an increasing emphasis on literacy and math and additional exposure to standardized tests in preparation for more later in their schooling.

The study, based on teacher surveys from 1998 and 2010, found that kindergarten shifted dramatically in just those dozen years. More teachers were using worksheets and having children compose and write sentences. Fewer teachers had art, science and dramatic play areas or water tables. In 1998, 31 percent of teachers said they believed that most children should learn to read in kindergarten, but by 2010, 80 percent held that belief.

Researchers were floored by how drastically kindergarten has shifted.

“To think that kids’ experiences in the early grades changed so much over such a short period of time is really surprising to us,” said Daphna Bassok, an associate professor of education at the University of Virginia.

Bassok said she believes the shift in kindergarten is rooted in a “trickling down of accountability pressures,” with schools under more demands to ready children for standardized tests that are used to evaluate teachers and schools. Bassok also pointed to the rise in the number of children attending preschool, which can create an early-achievement gap before kids even make it to elementary school.

While children of past generations often entered kindergarten with a blank academic slate, many schools now hope new students will have mastered the basics of counting to 10 and reciting the alphabet by the time they enter the classroom. And by the end of the kindergarten year, many more teachers expect children to know how to read and master skills once reserved for first-graders.

Jo Ann Bjornson, right, worried about whether she was sending her daughter Isabella, bottom right, to school too soon given the more strenuous environment. (J. Lawler Duggan/For The Washington Post)

At a packed information night in an Arlington high school auditorium in February, educators outlined what children should have before they enter kindergarten. Parents learned about the basic requirements: inoculations, birth certificates and proof of residency. But first they learned about how to prepare their youngsters for class: The children should be putting together puzzles, trying their hand at writing, and bolstering motor skills by zipping and tying things.

Many parents now see high-quality preschool as essential to their children’s education and get them started young. Even preschools feel more academic than they used to.

Kim Ngeh, a property manager in Arlington, moved her son Kaiden from home-based day care to Head Start, a preschool for low-income families, after a family advocate from Northern Virginia Family Service convinced her that preschool would be better — if not essential.

“It’s a very good program. It gets them ready for school,” Ngeh said, adding that Kaiden, now 4, already gets homework that includes coloring and tracing letters. “She said that it would be pretty important.”

For many children, kindergarten is the first introduction to school. Ana Bonilla-Galdamez, a social worker at Charles Barrett Elementary in Alexandria, said many children who enter as 5-year-olds have spent their childhoods in unstructured day care or in households with relatives who don’t speak English. Many of the students who are classified as English language learners were born in the United States but have little exposure to English.

“The difference is so great in kindergarten,” Bonilla-Galdamez said. “You cannot expect all the kids to move at the same speed.”

As part of a school tour and orientation at Garrett Park Elementary in Montgomery County, Md., children were allowed to get on a school bus and hang out to get familiar with them. August Fitzgerald, 5, was thrilled and didn't want to get off. (Michael S. Williamson/The Washington Post)

Kate Martin started school in the same light-filled classroom at Douglas MacArthur Elementary School where she now teaches. And on its walls, she can trace the evolution of kindergarten.

As a 5-year-old, Martin remembers the walls plastered with creative artwork, a special nook for snack time and a play area littered with blocks.

Martin’s walls are covered with words and posters so that novice readers catch a glimpse of letters nearly everywhere they look. There are orderly tables and independent reading lessons — academics that used to be reserved for first-graders that have been repackaged into interactive lessons for younger, squirmier students.

The U-Va. researchers who studied changes in kindergarten programming pointed out that the new emphasis on math and reading does not necessarily mean the fun has been stripped from kindergarten and replaced with rigorous academic instruction. In many cases, kindergarten teachers have found play-based approaches to teaching academic subjects to keep young students engaged.

“We do try to incorporate as much play and hands-on as we can,” Martin said. She teaches children to be independent, allowing them to select their own books so they will be more motivated to learn to read.

Martin said she has seen kindergarten getting more rigorous during the 15 years she has been teaching. Virginia has raised its expectations for what students learn in their first year of school in all subjects. In math, for example, the state in 2009 decided that kindergartners should be able to count to 100 by the end of the year instead of to just 30.

Martin said her young students appear to be rising to the challenge. It helps, too, that most of her students attended preschool.

“You’ll find that a lot of them say ‘I want to learn to read. I want to learn to write,’ ” Martin said. “They already have that motivation.”

During a science lesson last school year, children in Martin’s class built tiny boats out of aluminum foil and then set them in bins full of water. Then, they guessed how many pennies the boats could hold and dropped the coins in one by one until the boats sank, squealing and giggling as they watched their constructions slip beneath the water. It felt like play, but the children also practiced counting and learned about making hypotheses.

Mike Favila, an Arlington parent who was educated at a strict private school in the Philippines, said he was worried his son would be missing out on play when he headed to kindergarten.

“I was a little concerned it was going to immediately throw him into this rat race of academics that was going to scare him all the way into adulthood,” Favila said. But he was reassured when he visited schools and found the children to be relaxed — not stressed — and teachers mixing play with learning. His son Derek, 5, started at Claremont Elementary, a Spanish immersion school, this month, and he loves the experience, sometimes arriving home counting in Spanish.

Izzy Lieberson, 5, watches his sister Sylvia as his parents work on the paperwork for his enrollment in kindergarten at Garrett Park Elementary School. (Michael S. Williamson/The Washington Post)

Jessica Lieberson took her child Izzy to visit their neighborhood school, Garrett Park Elementary in Montgomery County, in April for an orientation. She said she wants her son to learn “to play and be part of a community” in kindergarten.

“Social skills are more important than the rigorous academics,” Lieberson said. “Developing the skills to work with others is definitely the most important thing.”

Bjornson said she was confident her daughter could handle the academics but was worried about whether Isabella, who once upset easily, was emotionally prepared for the transition. On Isabella’s first day of school she had her answer: She tore down the hall of their Arlington home screaming, “First day of kindergarten!”

By the second week, Bjornson said Isabella had made friends, brought home art projects and excitedly recounted what she was learning in class. She raves about the songs in Spanish and the penguin dance in gym.

“She’s coming home happy and excited,” Bjornson said. “I think the decision was right.”