# Why a tree blooms in fall

> Why a lilac, crabapple, dogwood or magnolia opens flowers in October, what a fall bloom costs next spring, and which natives, like witch hazel, bloom in fall.

Published 2026-11-06. Tags: How trees work. By Blue Whale Trees, a native tree nursery in the United States. Web version: https://bluewhaletrees.com/articles/why-a-tree-blooms-in-fall/

A spring-flowering tree or shrub that blooms in fall is opening some of next spring's flower buds early. Those buds formed in early summer, and a hard summer of heat, drought or early leaf loss can leave them ready to open when warm days follow cool ones. The plant takes no harm, but each bud that opens now is one fewer in spring. A few natives bloom in fall by habit.

![A full cluster of pale lavender common lilac flowers against a clear blue sky, a few dark green leaves at its base](https://bluewhaletrees.com/img/articles/why-a-tree-blooms-in-fall-1-1000.jpg?v=f80346bf "Common lilac, which we do not grow, in flower in Ewing Township, New Jersey, on October 6, 2025. Lilacs set next spring's flower buds in early summer, and stress can open some in fall.")
*Photo: Famartin, [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0) ([source](https://commons.wikimedia.org/wiki/File%3A2025-10-06_11_28_49_Out-of-season_lilac_flowers_along_Lochatong_Road_in_the_Mountainview_section_of_Ewing_Township%2C_Mercer_County%2C_New_Jersey.jpg))*

## Why the buds open early

Spring bloomers set next year's flower buds in early summer, shortly after the last flowers fade. As fall cools, they go dormant, and they open only after a winter's cold meets their [chilling requirement](https://bluewhaletrees.com/articles/glossary/index.html.md#chilling-requirement).

Heat, drought, heavy pruning and leaves stripped early by [leaf spot](https://bluewhaletrees.com/articles/spots-powder-and-speckles-on-tree-leaves/index.html.md) or insects can upset that order, pushing a plant into a dormant-like state in late summer. When warm days follow the first cool nights, some buds open as if spring had come, most readily where early leaf fall left them in the sun.

## Which trees and shrubs do it

Lilac, forsythia, cherries, apples, pears, crabapples, azaleas and some magnolias all do it. Among natives, [flowering dogwood](https://bluewhaletrees.com/plants/flowering-dogwood/index.html.md) is known for it:

> "Dogwoods are known to bloom in fall when they get rain after a stressful summer." (Walter Reeves, *Dogwood – Blooming in Fall*)

[Eastern redbud](https://bluewhaletrees.com/plants/eastern-redbud/index.html.md), the serviceberries and the native magnolias also [set next year's flower buds in summer](https://bluewhaletrees.com/articles/pruning-at-the-branch-collar/index.html.md) and can do the same. Blue Whale Trees grows native crabapples, cherries, azaleas and magnolias. We do not grow lilac, forsythia, apple or pear.

## What it costs next spring

Each fall flower is a spring bud spent, and the plant makes no new flower buds before spring. A few stray flowers cost little, but a heavy fall bloom can strip the spring show:

> "If your normally spring-flowering plants bloomed much at all this fall, you will see fewer blooms - and sometimes none - next spring." (University of Kentucky College of Agriculture, *Flowering ornamentals in fall May mean fewer blossoms this spring*)

## Natives that bloom in fall by habit

These flower late every year and never in spring, in the order they open:

- [Franklin tree](https://bluewhaletrees.com/plants/franklin-tree/index.html.md): white flowers from July until frost. Zones 5 to 9, 10 to 25 feet.
- [Groundsel bush](https://bluewhaletrees.com/plants/groundsel-bush/index.html.md): flower heads from August into October. Zones 5 to 10, 5 to 12 feet.
- [Seaside alder](https://bluewhaletrees.com/plants/seaside-alder/index.html.md): gold catkins in August and September. Zones 3 to 9, 12 to 30 feet.
- [Cedar elm](https://bluewhaletrees.com/plants/cedar-elm/index.html.md): flowers in August and September, some years again in October. Zones 6 to 9, 50 to 70 feet.
- [September elm](https://bluewhaletrees.com/plants/september-elm/index.html.md): slender hanging flower clusters in September. Zones 4 to 8, 60 to 70 feet.
- [Witch hazel](https://bluewhaletrees.com/plants/witch-hazel/index.html.md): yellow ribbon-like petals from September or October into December. Zones 3 to 8, 12 to 20 feet.

For each, this is the year's only bloom. Flora of North America counts seaside alder the only North American member of a mostly Asian group of fall-blooming alders.

A spring bloomer's fall flowers open here and there, on lilac most often near the top, where it is sunnier and warmer. Some garden lilacs are bred to bloom twice, so their fall flowers are normal.

![Spidery yellow witch hazel flowers along a twig among golden fall leaves, set against a dark background](https://bluewhaletrees.com/img/articles/why-a-tree-blooms-in-fall-2-1000.jpg?v=10528176 "Witch hazel in flower among its golden fall leaves in Woodbridge, Virginia, on November 20, 2021. It blooms every fall, and its fruit ripens a year later.")
*Photo: Judy Gallagher, [CC BY 2.0](https://creativecommons.org/licenses/by/2.0) ([source](https://commons.wikimedia.org/wiki/File%3A322_365_Witchhazel_-_Hamamelis_virginiana%2C_Woodbridge%2C_Virginia%2C_November_20%2C_2021_%2851694070266%29.jpg))*

## What to do next

Nothing undoes a fall bloom, but good care makes the next one less likely:

- [Water deeply in a drought](https://bluewhaletrees.com/articles/drought-and-an-established-tree/index.html.md), and keep watering into fall until the soil cools to about 40 degrees.
- Rake up leaves dropped early by leaf spot, to cut next year's infections.
- Prune a spring bloomer lightly, [right after it flowers](https://bluewhaletrees.com/articles/pruning-and-renewing-native-shrubs/index.html.md).

The [bloom and fruit calendar](https://bluewhaletrees.com/tools/calendar/index.html.md?plants=franklin-tree,groundsel-bush,seaside-alder,cedar-elm,september-elm,witch-hazel) opens here with these six, and it gives the months of every plant we grow.

## Common questions

### Will my tree still bloom in spring?

Usually, though with fewer flowers, since each bud that opened in fall is spent and no new ones form over winter. A heavy fall bloom can leave few or none, and a normal summer then sets a full crop of buds again.

### Is it bad for a tree to bloom in the fall?

No, the tree takes no harm, though the bloom points to a stressful summer. Water it in dry spells and watch for leaf disease and pests next year.

### Do redbuds bloom in the fall?

Not by habit: eastern redbud flowers in early spring. Its buds form the summer before, though, so a stressful year can open a few early.

## Sources

- [Why is my lilac blooming in fall, instead of spring?](https://yardandgarden.extension.iastate.edu/faq/why-my-lilac-blooming-fall-instead-spring): Iowa State University Extension and Outreach, Yard and Garden: flower buds set in early summer, heat, drought, defoliation by disease or pests and heavy pruning as the triggers, the dormant-like state, no harm but fewer flowers in spring, nothing to be done once fall flowers show, good care in stressful summers, and cultivars bred to bloom in fall.
- [Flowering ornamentals in fall May mean fewer blossoms this spring](https://news.mgcafe.uky.edu/article/flowering-ornamentals-fall-may-mean-fewer-blossoms-spring): University of Kentucky College of Agriculture, College News (November 5, 1998): the quotation on fewer blooms, lilac, crabapples, cherries, apples and pears in fall bloom, no new flower buds before spring, buds opening with warm fall days, leaves shed in drought and unshaded buds warmed by the sun, and buds set again after a normal summer.
- [Why are some spring plants blooming now?](https://extension.missouri.edu/news/why-are-some-spring-plants-blooming-now): University of Missouri Extension: drought stress and swinging fall temperatures behind fall bloom, watering trees into fall until the soil cools to 40 degrees, and watching for leaf disease and pests the next year.
- [Why is My Lilac Blooming in the Fall?](https://homegarden.cahnr.uconn.edu/2025/10/18/lilacs): UConn Home and Garden Education Center (2025): lilacs, cherries, forsythia, crabapples, azaleas and some magnolias setting buds in early summer, early leaf loss to leaf spot, cooler weather then warmer weather opening buds, the tops of lilacs where it is sunnier and warmer, a few flowers or many, no harm to the plant, and raking up infected leaves.
- [Sometimes spring flowers occur in fall](https://news.harvard.edu/gazette/story/newsplus/sometimes-spring-flowers-occur-in-fall/): Harvard Gazette, from the Arnold Arboretum (November 29, 2012): flower buds going dormant as temperatures drop after summer and opening with warmth once their cold hours are met, and Franklin tree flowering in fall by nature.
- [Understanding dormancy and chilling hours in perennial fruit crops](https://blog-fruit-vegetable-ipm.extension.umn.edu/2024/11/understanding-dormancy-and-chilling.html): University of Minnesota Extension (Madeline Wimmer, 2024): the deep dormancy that holds buds shut until enough winter chilling has built up.
- [Dogwood – Blooming in Fall](https://www.walterreeves.com/landscaping/dogwood-blooming-in-fall/): Walter Reeves, The Georgia Gardener (2012): the quotation on dogwoods blooming in fall when rain follows a stressful summer, and little effect on the spring bloom from a few fall flowers.
- [Hamamelis virginiana, Fire Effects Information System](https://www.fs.usda.gov/database/feis/plants/tree/hamvir/all.html): USDA Forest Service: witch hazel's flowers opening in September and October and its fruit ripening the next fall.
- [Alnus maritima, Flora of North America](http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233500036): Flora of North America: seaside alder flowering in late summer and early fall, the only North American member of a mostly Asian group of fall-blooming alders.

## Related

- Next step: [Open the bloom calendar](https://bluewhaletrees.com/tools/calendar/index.html.md?plants=franklin-tree,groundsel-bush,seaside-alder,cedar-elm,september-elm,witch-hazel)
- [Why a tree flowers but bears no fruit: it may be a male, lack a partner nearby, or be too young](https://bluewhaletrees.com/articles/why-a-tree-flowers-but-never-fruits/index.html.md)
- [Mast years: why oaks, hickories and beech bear a huge crop one fall and almost none the next](https://bluewhaletrees.com/articles/mast-years/index.html.md)
- [Why leaves turn red and yellow in fall, and which native trees give each color](https://bluewhaletrees.com/articles/why-leaves-turn-red-and-yellow-in-fall/index.html.md)
- [Caring for native trees and shrubs season by season](https://bluewhaletrees.com/articles/caring-for-native-trees-season-by-season/index.html.md)