Forty years is a long time for a tree to grow, but an even longer time for a memory to take root.

In the spring of 1984, my husband Mark and I were exhausted, terrified, and blissfully happy. We had just brought our daughter, Lily, home from the hospital. The day after we settled in, Mark went out to the backyard with a tiny oak sapling in a plastic black pot. I watched him through the kitchen window as he dug a hole right near the edge of our property, patting the soil down with his bare hands.

“This tree is going to grow up right alongside her,” he told me that night, wiping dirt on his jeans. “By the time she has kids, it’ll be a giant.”