I pushed a thin Niobe golden weeping willow cutting into the damp back corner one spring. It was a pencil-sized stick when it went in the ground. From the kitchen window I watched it climb, and in a handful of years its top brushed the roof gutter. That climb is normal for this tree. A five-year-old weeping willow stands 15 to 20 ft (4.5 to 6 m) tall, and the willow tree growth rate is one of the fastest you will find in any yard tree.
The math is simple once you know the yearly pace. A healthy willow adds 3 to 4 ft (1 to 1.2 m) every season. Stack five of those seasons on top of each other and you land near 15 to 20 ft (4.5 to 6 m). That steady jump shapes the weeping willow size by age. A two-year tree looks small. A five-year tree already towers over a grown adult. I measured mine against the back door each spring, and the gain from one year to the next was easy to see by eye.
Your numbers will shift with the spot you pick. Water is the big lever here. A willow with wet feet and rich soil hits the top of that range, while a tree in dry, poor ground lands closer to the low end. Warmth matters too. A long growing season in the south pushes more growth than a short, cold one up north. Sun helps as well, since a tree in full light builds wood faster than one stuck in shade.
At year five you also see the crown spread, not just the height. The branches arch out and droop, so the tree reads as wide and full even when it is only 15 ft (4.5 m) tall. My own tree threw shade over half the back fence by its fifth summer. That spread is part of why a willow feels much bigger than its raw height suggests.
The tree does not stop at year five either. It keeps racing toward a mature 30 to 50 ft (9 to 15 m) tall, and just as wide across the crown. On a good wet site, a willow can approach that full size within ten to fifteen years. Few yard trees fill their space this fast. A maple or oak in the same corner would still be a modest sapling while your willow shades the whole yard. That speed is part of the charm and part of the problem.
This pace is the reason siting matters so early. A fast growing willow does not stay small while you make up your mind. The little sapling you plant this spring becomes a wide tree with a sprawling root zone faster than most people expect. Those roots chase water, so keep the tree well clear of pipes, septic lines, and your foundation. A willow root can reach far past the spread of the branches above.
Give it room before you plant, not after. Set a young willow at least 35 to 50 ft (10 to 15 m) from the house and any water lines. Pick a low, damp corner where it can drink its fill. Water it well through its first two summers so it roots deep and grows on schedule. Plan for the size it will reach, not the stick you hold in your hand today. Do that one thing right and you get the graceful sweep of those branches with none of the headache.
Read the full article: Weeping Willow Tree: A Complete Guide
