Not long ago, my husband and I planted a tree. We watered it and provided it with light and sustenance. We dreamed of the day when it would reach maturity and tower over us. But as we nurtured our crop and watched it grow, the unexpected happened. We too began to develop and blossom.

That tree is our three-year-old son. And just as Jewish law requires a farmer to leave a newly planted tree unharvested for the first three years as a gift to G‑d, we left our son’s hair untouched.

Recently, we celebrated his upsherin, in which we cut his hair for the first time. Although I had longed for the day when I would not have to battle his unruly curls, I approached the milestone with reluctance. An upsherin, which literally means “shearing off” in Yiddish, marks the beginning of a child’s formal Jewish education. But it also marks the end of his babyhood.

When my husband first told me of his family’s observance, I produced a myriad of arguments. I wanted a cherubic-looking baby with neatly cropped hair, and didn’t have time for grooming long tangled hair. Besides, the custom clashed with my modern sensibilities. Such traditions are more appropriate for chassidic Jews in tightly insulated communities, where everyone adheres to a rigid brand of Judaism. How would I explain his appearance? Everyone would mistake him for a girl.

But I also marveled that the tradition has been carried down through generations of my husband’s family. It is a joyous expression of faith that connects his ancestors to their descendants in a meaningful way. Living Jewishly, I realized, is more than following a series of dos and don’ts. It is a lifestyle we can make richer and more fulfilling through spontaneous acts that make our religion come alive. I decided that continuing the tradition must supersede my own preference.

The root of the upsherin is a verse in the Torah which compares man to a tree. Just as a tree emerges from a tiny seed to grow tall and bear fruit, so a small child grows in knowledge and bears the fruit of his good deeds. Therefore, just as the Torah requires that newly planted fruit trees grow unharvested for three years and then have their fruits offered to G‑d, the tradition calls for leaving a boy’s hair uncut.

Age three also marks a turning point in a child’s intellectual development. In the first months of my son’s life, I saw few “fruits,” or tangible manifestations of my child-rearing efforts. Now, however, I see the harvests of holiness and rewards of his education. He actively participates in religious rituals, reciting the blessings and prayers with enough fervor to inspire an atheist.

But his long mane took some getting used to. He refused to wear a ponytail or hat, so I couldn’t hide his growing mass of curls. As I strolled around town with my hippie, everyone commented on my beautiful girl. My modern and non-Orthodox friends were shocked that someone like me would keep such an “old world” tradition.

In time, as my son grew taller and his hair grew longer, the tradition grew on me. I found beauty and meaning in it, and embraced it as my own. When I explained the custom to others, most found it as lovely as I did. If they didn’t, I assured them that my son’s head start on long hair would spare him from a long-haired rebellion in the teens. When strangers complimented my girl, I thanked them and demonstrated the truth by changing his diaper on the spot.

I soon discovered that I was not the only mother outside of Borough Park whose son resembled a flower child. Numerous modern Orthodox families have adopted the custom in recent years, and are finding creative ways to celebrate it. Some travel to Tzfat to cut the hair at the grave of Rabbi Shimon bar Yochai. Others take the child to a yeshivah, where the child is serenaded with biblical verses.

Planning my son’s upsherin was intimidating, because I had never attended one. Luckily, I had a Lubavitch friend, Zalman Shmotkin, who filled me in on the details. He provided us with an assortment of beautiful ideas, and we adapted them to reflect our personalities. We learned that it is preferable to hold an upsherin in a holy place and to have a righteous person cut the hair. So we made it in our synagogue, and gave the first snip to a rabbi we admire. It is also customary to dip the child’s fingers in honey and place them on Hebrew letters, to bring home the sweetness of learning. Instead we had Torah-shaped lollipops, a cake with a little Torah on top and a musician playing Hebrew music.

Our rabbi spoke eloquently, but my son, dressed in checkered pants and a matching vest, stole the show. He stood up on a chair and sang Torah Tzivah Lanu Moshe with as much gusto as a guy in a beer commercial. Then it was haircut time. Our rabbi took the first cut—at the precise spot, he announced, where my son will someday place his tefillin. I squeezed my eyes shut, half expecting the same cries I heard at his bris (circumcision), which seems like it was just yesterday. But when I looked up, he was grinning. The only teary eyes were mine.

As we snipped off his baby locks, we symbolically cut my son away from my umbilical cord and pushed him towards adulthood. I watched as the scissors were passed from our rabbi to our parents and friends, and felt my child moving away from the security of my womb into the larger community.

When it was all over, we made a circle around my son and danced. He was enthusiastic about his new hairdo, which was finished off by a professional barber. Peering into the mirror, he proclaimed, “I’m a man!”

Most parents save the hair for posterity. We gave it away to a better cause. The morning after the upsherin, I mailed my son’s golden curls to Locks for Love, an organization that makes wigs for children who lost their hair to cancer. It was uplifting, knowing that someone else will benefit from my son’s upsherin.

For the next few days I kept staring at my son, who suddenly looked older. My baby was gone, replaced by a toddler. I vowed to savor this new stage by memorizing his antics and capturing him on camera. But I foresaw the future: fewer kisses, less handholding and bedtime stories.

Eventually he will want to plant his own garden, and will move out from our house into his own. The peace and quiet I had craved when he was born will return more quickly than I had anticipated. Sometimes I wish man was more like a tree, unchanging and rooted in time and place through centuries. But I know that this is not our calling. As we grow, we travel away from our roots into new homes, friendships and careers. We aim to make our mark on the world, but as the seasons change, our works are forgotten. Much of our accomplishments are as fleeting and temporary as the leaves that bloom in the spring and fall in the autumn.

But I am comforted, knowing of the small things we can do that are everlasting. We can plant a tree. We can create happy memories. We can pass on a beautiful custom to our children. That, after all, is the ultimate gift we can give our descendants.

Someday, I hope, as my son’s branches extend to form new seedlings, he will say as much to his children.