How to Plant a Tree, Part 3: Getting the Timing Right

What Is the Best Time to Plant Trees in Nashville?

In the commotion of spring planting, it might seem like you can plant anything and it will burst into growth, but the best time to plant trees is in the fall! That’s because tree roots are most active in the colder months of the year, which gives them time to settle into place and get ready to bud and bloom in the spring. Here, we’ll go over some light biology to explain why tree planting stands apart as a cool-season activity, as well as how to plant a tree for long-term success.

Trees in Cool-Weather Months

Trees are the ultimate perennial plant: they are planted once, and they grow year after year for decades. Like other perennials, trees lose their greenery in the fall and survive the winter off of energy stored in their roots, which are insulated by the soil over the winter.

As there’s less and less sunlight and the temperatures start to drop, trees prepare for winter dormancy. Deciduous trees, like oaks, maples, and other broad-leaf trees, will drop their leaves as the tree conserves energy by drawing the carbohydrates they produce by photosynthesis from the upper extremities (the leaves and branches) down into the roots. 

While the warm months are when trees have the most above-ground growth, the cool months are when the roots are able to use the tree’s stored energy to focus on underground growth. Even evergreens, which don’t lose their leaves, slow their growth in fall and winter, using that downtime to expand their roots.

The Best Times of Year to Plant Trees

In Nashville, tree-planting season starts at the beginning of fall and goes through winter, which is why the Nashville Tree Conservation Corps tree sale deliveries begin in mid-October of each year. The changing of leaf colors is a good signal that it’s safe to start planting trees, and unless the ground is frozen, a tree can be planted in the winter as well. The more time the tree has to spread its roots, though, the better.

The Worst Times of the Year to Plant Trees

While early to late fall is the best time to plant a tree and throughout the winter is still good, the worst times to plant a tree are in the late spring and summer. If a tree misses its opportunity to spread its roots, the tree might not be able to get as much water as it needs—or worse, the tree may miss its opportunity to bloom. Without the protection and productivity of leaves, a sapling’s chances of survival significantly decrease because it will be exposed to the hot summer sun without being able to produce the energy the tree needs to survive. 

When it comes to the summertime, it’s best to wait until the season has passed to plant a tree rather than taking the risk of killing it before the tree has a chance to establish itself. Even healthy, mature trees can be damaged in the summer from drought or leaf scorch from intense sunshine.

Sleep, Creep, Leap

In our article on the early establishment stages of a tree, we go over the tree’s first three years of life. The first stage is “sleep,” where a tree doesn’t appear to be doing much, but its below-ground work is active and important. In the second year, it “creeps” with slow but steady upper growth, and it leaps in the third year as the happy tree is able to finally thrive in place. Those first few months after a tree is planted are essential for a tree to spread its roots and make it through the first few years in your yard.

Caring for Newly Planted Trees in Fall and Winter

Not only does the tree need to spread its roots for stability, but the roots are the mouth of the tree and must reach around in the soil for water, nutrients, and oxygen, which then feed the body of the tree and allow it to stretch outwards and upwards. Focusing on the health of a sapling’s roots is essential to successful growth, so be sure to plant it in aerated soil, and do not bury the roots so deep or pile on so much soil or mulch that they suffocate. 

Tree roots are attracted to moisture, so a regular supply of water is essential (but too much will drown the roots). Avoid fertilizing a newly planted tree in fall as well, since the boost of extra nutrients may stress out the tree. Those nutrients are useful for stem and leaf growth, but they can overload a tree in dormancy when it can’t actually use them. 

For more tips on planting and caring for trees, be sure to subscribe to our email newsletter, and consider volunteering with us to get out in Nashville neighborhoods and support the local canopy throughout the city!