Plant Highlight · Bigleaf & Ashe Magnolia · Aiken, South Carolina
The Trees That Carry the Largest Flowers in North America
On the bigleaf magnolias, a pair of Southern natives that grow leaves the size of canoe paddles and blooms you can hold in two open hands.
In this guide
I.A tree built on the scale of exaggeration
Every so often a plant refuses to be tasteful about it. The bigleaf magnolia, Magnolia macrophylla, is one of those plants. It holds a quiet national record, two of them, in fact: the largest simple leaf and the largest single flower of any tree native to North America. The leaves stretch to roughly thirty inches, silver-backed and soft, hung out along the branches like the sails of some slow green ship. The flowers open to nearly a foot across, creamy tepals cupped around a rose-purple stain at the throat, and they smell of lemon and warm cellar and something older than either.
You do not so much notice a bigleaf magnolia as get caught by it. In the mesic hardwood coves of the Southeast, where the species drifts through the understory in scattered, uncommon stands, a single tree can stop a walk cold. Nothing else in the temperate woods looks like it. Nothing else asks you to reconsider your sense of scale quite so cheerfully.
A single leaf can be longer than your forearm, and a single flower wider than the span of your two hands. This is not a tree that whispers.
II.Meet the family: macrophylla, ashei, and the hybrid
Gardeners tend to say "bigleaf magnolia" as if it were one plant. It is really a small, closely related company of them, and the differences matter a great deal once you have a spot in mind. Here are the three we grow, each with its own temperament.
Bigleaf Magnolia (Magnolia macrophylla)
- Native Southeast
- Canopy tree
- Fragrant
- Pollinator
- Zones 5b–8
The full-sized original. Given rich soil and shelter it can climb to forty feet and beyond, a straight-trunked understory tree that unfurls those paddle leaves in a loose parasol. Patient by nature: it takes a few years to settle before it flowers, and rewards the wait with the largest blooms of the genus. Best where it has room and a wind break.
Shop Magnolia macrophylla →Ashe Magnolia (Magnolia ashei)
- Best Seller
- Florida endemic
- Large shrub
- Fragrant
- Blooms young
The bigleaf magnolia for people who do not have a forest. Endemic to a handful of ravines in the Florida Panhandle, and endangered in the wild, Ashe magnolia stays a large shrub or small tree, often ten to fifteen feet, roughly half the height of its northern cousin. Its party trick is precocity: it will open those enormous flowers while still knee-high, sometimes at a foot tall. If you want the drama without the decades, this is the one. It is our best seller for good reason.
Shop Magnolia ashei →Ashe × Bigleaf Hybrid (Magnolia ashei × macrophylla)
- Very Rare
- Colossal foliage
- Dinner-plate blooms
- Pollinator
A deliberate cross between the two, and a rare thing to find offered anywhere. It aims for the sweet spot: the youthful, generous flowering habit of Ashe with a nod toward the stature and leaf of macrophylla. A collector's plant, and a conversation that lasts a lifetime.
Shop the Ashe × bigleaf hybrid →
Field Note
Ashe magnolia was long filed as a subspecies or variety of Magnolia macrophylla, and you will still see it listed that way (M. macrophylla subsp. ashei). Botanists now generally treat it as its own species. In the garden the practical difference is simple: Ashe stays small and flowers early; macrophylla grows tall and takes its time.
III.The oldest handshake in the garden
To grow a magnolia is to keep company with deep time. The genus is ancient, older than the bees, and its flowers were designed for a different pollinator entirely. Beetles came first, and beetles are still the primary visitors, clambering into the cupped blooms after the protein-rich pollen. The magnolia's answer to their blunt, gnawing appetite is a flower engineered like armor: thick, waxy tepals and a hardened carpel that shrugs off the chewing. What looks to us like a study in softness is, structurally, a fortress that predates the daisy and the rose by tens of millions of years.
The magnolia opened its first flowers for beetles, before there were bees to teach the world a gentler manner. It has never quite updated the design, and it has never needed to.
There is a lesson in that for the gardener with a long horizon. These are not plants that trade on quick color and casual replacement. They are plants that were here before our idea of a garden and will likely outlast it, which is exactly why they belong in a landscape you intend to hand to someone.
IV.Where they want to live
In the wild, bigleaf magnolias are woodland-edge and understory trees of rich, moist, well-drained loam. That single sentence contains almost everything you need to grow them.
They want shelter above all. Those famous leaves are gorgeous and structurally expensive, and a hard wind will shred and brown them by August. Plant on the lee side of the house, at a woodland edge, or among taller trees that break the gusts. They want moisture without waterlogging: think of a forest floor that stays cool and damp but never turns to standing water. And they want dappled light or morning sun, especially in the lower South, where full exposure to a Carolina afternoon is more than the foliage cares to negotiate.
Give them those three things and they are, honestly, low-maintenance to the point of ingratitude. Mulch to keep the roots cool, water through the first couple of summers while they settle, and then mostly leave them be.
Field Note
The leaves are deciduous, and in autumn they drop whole and enormous, like a delivery of brown paper. Some gardeners find raking them a chore. We find it one of the more satisfying sounds of the season, and the leaves compost beautifully. If tidiness is a priority, site the tree in a bed rather than over a lawn.
V.Growing them well: a field table
The quick reference, distilled from the nursery and the woods.
| M. macrophylla | M. ashei | |
|---|---|---|
| Mature size | 40 ft or more | 10–15 ft (large shrub) |
| Leaf length | To ~30 in | To ~24 in |
| Flower width | To ~12 in | To ~12 in, often precocious |
| Years to first bloom | Several (patient) | Can flower knee-high |
| Bloom season | Late spring into early summer | Late spring into early summer |
| Cold hardiness | USDA 5b–8 | USDA 6–9 |
| Light | Part shade to morning sun | Part shade to morning sun |
| Soil | Rich, moist, well-drained | Rich, moist, well-drained |
| Best for | Woodland gardens, large yards | Smaller gardens, quick reward |
VI.Design, or how to plant a leaf you can read a letter through
A bigleaf magnolia is a specimen plant in the truest sense: one is a statement, and three is a crowd shouting the same word. Give it a clean backdrop, a wall of dark evergreens, a stretch of lawn, an open sky, and let the foliage do the talking. The scale reads best when there is emptiness around it to measure against.
For the courtyard or the smaller lot, reach for Ashe. It brings the identical outsized flower and leaf down to a shrub you can walk past and touch, and it flowers young enough that you will not have to explain to visitors what it will look like someday. Underplant with woodland natives that enjoy the same cool, rich shade, and you have a scene that feels less like a border and more like a fragment of the coves these trees came from.
Plant one where a person turns a corner. The double take is the whole point.
VII.Common questions
How long until my bigleaf magnolia flowers?
It depends on which one. Magnolia macrophylla asks for patience and generally settles in for several years before blooming well. Magnolia ashei is famously precocious and can open flowers while still a small shrub, sometimes within a year or two of planting. If waiting is not your virtue, choose Ashe.
Will the leaves really tatter in wind?
They can. The leaves are large, thin, and soft, which is the source of their beauty and their vulnerability. A sheltered site, out of the prevailing wind, keeps them handsome through the season. This is the single most important siting decision you will make.
Are these trees fragrant?
Yes, and memorably so. The flowers carry a rich, lemony, slightly spicy scent that travels on a warm evening. It is one of the quiet arguments for planting near a porch or a path where you will actually encounter it.
Is Ashe magnolia endangered? Should I feel odd about growing it?
The opposite. Ashe magnolia is endemic to a very small area of the Florida Panhandle and is listed as endangered in the wild because of that limited range. Nursery-propagated plants like ours take zero pressure off wild populations, and growing this species in gardens across a wider geography is a genuine act of conservation by cultivation.
From the Nursery
We grow all three of these at the nursery here in Aiken: the towering Magnolia macrophylla, the garden-scaled and much-loved Magnolia ashei, and the rare Ashe × bigleaf hybrid. Stock on the bigleaf magnolias moves in flushes, so if a size sells through, it is worth checking back after a restock. If you would like help choosing between the tree and the shrub for your particular spot, we are always glad to talk it through.
References
Arnold Arboretum, Harvard University. "Bigleaf Magnolia." arboretum.harvard.edu
North Carolina Extension Gardener Plant Toolbox. "Magnolia macrophylla" and "Magnolia macrophylla var. ashei." plants.ces.ncsu.edu
Wikipedia. "Magnolia macrophylla" and "Magnolia ashei." en.wikipedia.org
UF/IFAS Extension. "Ashe Magnolia, Rare Beauty of the Florida Panhandle." blogs.ifas.ufl.edu
Missouri Botanical Garden Plant Finder. "Magnolia macrophylla." missouribotanicalgarden.org
