Cercis gigantea Seeds | Giant Redbud
LATIN NAME: Cercis gigantea
COMMON NAME: Giant Redbud
Plant Profile
The giant redbud does something most trees will not: it flowers on the wood, on last year’s branches and along the older trunk, before a single leaf appears. This cauliflory turns the whole bole into a column of pink-purple pea-flowers in early spring, so the tree looks lit from within before its canopy opens. It is a show that stops a passer-by, and it is the single fact that separates the giant redbud from the tame shrub redbuds most gardeners know. The blooms are small but many, packed in short clusters that trace every bare limb.
Born on the bark rather than the twig tips, the flowers use stored energy from the trunk to open ahead of the leaves, a strategy that puts the bloom in full sun before the canopy shades it. The species is a tree, not a shrub, reaching several metres with a rounded crown, unlike the lower eastern redbud that stays a small multi-stemmed form. The habit, the bark-flowering, and the larger heart-shaped leaves together mark it as the giant of the clan, a tree redbud rather than a bush.
In its Chinese home it is a feature of hilly woodland and village edges, planted for the spring show and tolerated for the light shade it casts. The leaves are broad, rounded, and heart-shaped, and the flat brown seedpods that follow the flowers hang on into summer, giving a second season of interest. As a garden tree it is prized where the climate is mild and the soil is sound, and it is gaining ground beyond Asia as a specimen for the early-year border.
In town squares and temple yards across its Chinese range it is planted as a spring feature, and the bark bloom is a local event when it opens. The tree is also grafted for a cleaner trunk in parks, where the pink flush on the bole draws crowds before the leaves stir.
Science & Biotechnology
The pink-purple colour of the blooms is carried by anthocyanin pigments in the banner petal, the same class of compounds that tints pea flowers and clover. The pea-family flower is built on the standard, wings, and keel plan, and the giant redbud follows it exactly, with the banner carrying the deepest colour. These pigments are what the eye reads as the tree’s signature, and they shift a little with soil and season, so no two springs show quite the same shade.
Uses & Benefits
After the flowers fade, the pollinated ones swell into the flat, papery pods typical of the genus, each holding a few seeds and rattling in autumn wind. The leaves, broad and notched at the base, give good summer cover and turn a soft yellow before they drop. The combination of bark flowers, heart leaves, and hanging pods makes the giant redbud readable in every season, a useful trait for a tree meant to be lived with.
Planted as a lawn specimen, the giant redbud gives a burst of colour when little else is open, then settles into a tidy shade tree for the rest of the year. It likes sun or light shade, a deep loam, and shelter from hard late frost that can nip the opening blooms. Bees work the flowers heavily, so it earns a place in a pollinator plan as well as an ornamental one, and the heart-shaped leaves make a soft echo of the redbud’s famous kin.
Growing from Seed
The seed lies in the flat pod and is slow to stir because of a hard coat, so the grower helps it along. Nick the coat or pour hot water over the seed and let it cool, then give it a cold rest through the cool months before sowing into warmth. The seedling builds a taproot fast, so a deep pot serves it better than a shallow tray, and the young tree rewards a second season of patience with real height.
Scald the seed in water that has just come off the boil, let it soak as it cools, and discard any that float, because a sunk, swollen seed is the one to keep. After the soak, hold the seed in damp chilling until the weather warms, then sow on the surface of a deep mix and thin to one strong plant. Move it out while small, because the redbud’s root, like the ash’s, bends against a long stay in a tray.
Our Take
For the shrub kin see Cercis canadensis, and for the same pea-family show the orchid tree Bauhinia blakeana, the golden chain Laburnum anagyroides, and the wisteria Wisteria sinensis. Giant redbud is the one to grow if you want the flowers on the trunk, not just the twigs.
Related Reading
If Giant Redbud appeals to you, these related plants are worth a look: