When to plant a tree: fall or spring, how late is too late, and what the frost dates decide

Plant a tree while it is dormant. In fall, that runs from leaf drop until about six weeks before the ground freezes, and in spring from the day the frost leaves the ground until the buds begin to swell. In the South, fall is best and the window runs on through winter, because roots keep growing through the mild months. In the North, spring is safer for bare-root trees and for some species, oaks and magnolias among them. A potted tree can go in whenever the ground is not frozen, given steady water, and seed keeps a calendar of its own.

What fall and spring give the roots

A new tree has to root into the soil around it before its first summer, and the season sets how long it gets. Roots grow most in cool weather, in fall and again from late winter into early spring, even while the tree looks dormant. In fall a new tree loses less water through its leaves, and air cooler than the soil drives roots rather than shoots.

In the Southeast, a fall-planted tree gets the whole winter:

“Unlike the tops of ornamental plants that go dormant and cease growth for the winter, roots of ornamental plants in the Southeast continue to grow throughout the warmer fall and winter months.” (Clemson Cooperative Extension, Planting Trees Correctly)

Farther north, a tree planted late in fall goes into the cold with few new roots. Freezing and thawing can also lift a fall-planted seedling out of heavy clay, a hazard called frost heaving. Spring gives a tree a whole growing season to root before its first winter, which is why northern sources favor it:

“Spring is still the optimum time to plant bare-root material in Iowa, but several factors may encourage a fall planting.” (Iowa State University Extension and Outreach, Fall Planting of Bare Root Seedlings)

Trees that do better planted in spring

Some trees are best planted in spring, among them those slow to establish and those with thick, fleshy roots that break easily and heal slowly in cold ground. Among the ones we grow:

• Northern red oak: bare-root saplings set out in early spring survive far better than fall-planted ones. Zones 3 to 8, 50 to 75 feet.
• Willow oak: it moves poorly in fall, so plant it in late winter or early spring. Zones 5 to 9, 40 to 75 feet.
• Sweetbay magnolia: its fleshy roots break easily, so it goes in as growth starts in early spring. Zones 5 to 10, 15 to 35 feet.
• Flowering dogwood: early spring beats fall in cold zones. Zones 5 to 9, 15 to 30 feet.
• American hornbeam: early spring suits it better than fall. Zones 3 to 9, 20 to 35 feet.
• Pawpaw: its fleshy roots break easily, so it goes in from a pot in early spring. Zones 5 to 9, 15 to 30 feet.

The University of Wisconsin’s list for spring planting adds the birches, cherries, plums, beech and evergreens. Its fall list, for September through early October, includes hackberry, catalpa, linden and most maples.

Bare-root, potted and seed

Bare-root stock is dug, shipped and planted while dormant, with no soil around its roots. In the North, fall suits bare-root hardwoods better than conifers. Blue Whale Trees ships live plants only while they are dormant, in February through May and in October and November. Seed and acorns ship year-round.

Potted and balled-and-burlapped trees can go in any time the soil is not frozen, and potted ones need the least watering when planted in late fall or early spring. Some species take less well to a fall planting as balled trees than to a spring one.

Seed keeps its own calendar. White-oak-group acorns sprout almost as soon as they fall and go in that fall. Red-oak-group acorns usually need a winter’s cold first, from a fall sowing or from weeks of cold, damp storage before a spring one. A fall-sown bed wants a mulch against frost heaving and rodents until spring frosts are past. The seed sowing planner dates each step for your state and zone, and planting acorns, nuts and seed covers the rest.

How late in fall, and how early in spring

Our tools hold three frost dates for each state and hardiness zone, from NOAA’s climate normals for 1991 to 2020. They are the median last spring frost, first fall frost and first night at 20 degrees. Each has even odds: in half of years the last spring frost comes later, and the first fall frost earlier. The planting-window tool turns the rules below into dates for your ZIP code.

In fall, count back from the ground, not the air. The first fall frost chills the air before the ground freezes, since the cold works down from the surface as the season goes on, more slowly under snow and in wet soil. Plant at least six weeks before your ground usually freezes, because new roots need warm soil.

In spring, dormant stock does not wait for the last frost. It goes in as soon as the frost is out of the ground and must be in before the buds begin to swell. In Pennsylvania that season runs from early March, weeks before the last spring frost, to early May.

Planting in summer, or after the window closes

A tree planted in summer has the least time to root before heat and drought, so summer planting is for potted stock, with regular watering. For the first months most of the tree’s water comes from the root ball, so water the ball itself and feel it before each watering. The watering calculator schedules water daily for the first two weeks, every two to three days to week 12, then weekly until established.

A tree that arrives when it cannot go in can wait. Heel a bare-root tree into damp soil or mulch, or pot it up in a well-drained mix kept from freezing, and plant it before the buds swell. A potted tree waits for weeks in shade if watered, and a sapling in a pot covers a longer wait. The steps from the box to the hole are in bare-root trees on arrival.

The windows by region

The bare-root and potted rows follow sources from Iowa and Illinois for the North, Maryland and Pennsylvania for the Mid-Atlantic, and the Carolinas for the South.

Where to start

Find your dates first, then match them to what you are planting:

• Planting-window tool: it turns these rules into dates for your ZIP code.
• Shipping page: the months live plants ship.
• Bare-root trees on arrival: what to do the day the box comes.
• Seed sowing planner: when to sow acorns, nuts and seed in your state and zone.

Common questions

Is it better to plant trees in the spring or the fall?

In the South, fall, because roots keep growing through the mild winter. In the North, spring is safer for bare-root trees and for some species, oaks and magnolias among them.

How late in the fall can you plant a tree?

Until about six weeks before the ground freezes, so new roots have time to grow in warm soil. In the Southeast, where roots grow all winter, planting goes on until spring.

Can you plant a tree in the summer?

A potted tree, yes, if its root ball gets regular water through the first summer. A bare-root tree goes in only while dormant.

When should bare-root trees be planted?

While dormant: in early spring after the frost leaves the ground and before the buds swell, or in fall after leaf drop. In the North, spring is better, above all for conifers.

Sources

• How to Plant Trees and Shrubs: The Morton Arboretum: six weeks before the ground freezes, warm soil for new roots, lower water loss and cool air over warm soil in fall, spring for slow-to-establish species and its longer season, the risk of planting late in fall, balled stock that takes less well to fall, and summer planting of container trees with regular watering from the root ball.
• Planting Bare-root Tree Seedlings in Spring: Penn State Extension: bare-root seedlings planted once the frost leaves the ground and before the buds swell, from early March to early May in Pennsylvania.
• Planting Trees Correctly: Clemson Cooperative Extension: roots that grow through the fall and winter in the Southeast, container and balled trees planted throughout the year and best in fall, and balled trees dug and planted in the cooler months after leaf drop.
• Fall Planting of Bare Root Seedlings: Iowa State University Extension and Outreach: spring as the optimum time for bare-root stock in Iowa, hardwoods doing better than conifers in fall, fall planting until the soil starts to freeze, and frost heaving on heavy clay.
• Tree Species Recommended for Fall Planting: University of Wisconsin-Madison Extension (Amy Freidig, 2024): the trees that do better planted in spring, and those for planting from September through early October.
• Planting a Tree or Shrub: University of Maryland Extension: dormant planting, fall, winter and early spring in unfrozen soil, fleshy-rooted trees planted in spring, container and balled trees any time the soil is not frozen, bare-root plants shipped and planted dormant, and potting up plants that cannot go in.
• 11. Woody Ornamentals: NC State Extension, Extension Gardener Handbook: root growth most active in cool weather in fall and from late winter into early spring, container plants needing the least watering when planted in late fall or early spring, bare-root plants installed while dormant, and the drought risk of late spring and summer planting.
• Quercus L., oak: USDA Forest Service, Woody Plant Seed Manual, Agriculture Handbook 727 (F.T. Bonner, 2008): white-oak-group acorns that germinate almost at once and go in in fall, red-oak-group acorns stratified before a spring sowing, mulched fall beds, and spring sowing in the South where mild winters may not complete the chilling.
• Frozen forests: University of Minnesota Extension: soil that freezes from the surface down as winter goes on, more slowly under snow and in wet soil.
• Readme for the 1991 to 2020 annual and seasonal normals by station: NOAA National Centers for Environmental Information: first and last freeze dates given at set probabilities and temperature thresholds, among them 32 and 20 degrees.