The question of nandina sun or shade has an easy answer. It grows in both. The catch is that the two settings hand you very different plants, and the gap shows up most in fall and winter color. Pick the spot based on the look you want, not on one rule that fits every yard.
I planted a row of Gulf Stream nandina along an east-facing foundation, and the two ends tell different stories. The end shaded by a wall corner stays a flat, dull green through the cold months. The end that catches morning and midday sun turns a deep, burning red. Same plant, same bed, same day I water them. The only thing that changed was how much light each end soaked up. I noticed the split most in January, when the red end looked lit from the inside and the shaded end just sat there green.
That difference comes down to pigments. Green leaves are full of chlorophyll, the stuff that runs photosynthesis. As the weather cools and the days shorten, the leaves make more red and purple pigments called anthocyanins. Bright light pushes that color higher. In full sun, those red and burgundy pigments stack up and the foliage glows through fall and winter. In deep shade the leaves hang onto most of their green. The plant also grows a little more open, with thin, loose stems that reach for light.
These light needs are wide for a shrub this showy. Extension sources put nandina light requirements at both ends of the scale, from full sun all the way down to deep shade. Few common landscape plants stretch that far. It also takes heat well, so a hot, exposed bed will not scorch it the way that same spot might burn a fussier shrub. You get a plant that bends to your yard instead of one that demands a narrow set of conditions.
So where should it go? If you want the boldest seasonal color, give your heavenly bamboo full sun. Six or more hours of direct light each day brings out the richest reds once the weather turns cold. A south or west wall that bakes in the afternoon works well, since the plant shrugs off that heat. Open beds with no overhead canopy give you the same payoff. The more sun the leaves catch, the deeper the winter red runs.
Plant in full sun for the strongest red and burgundy fall color. Part shade gives a softer, mixed look with some red and some green. Deep shade keeps the leaves green and the plant a bit loose and open, but it stays healthy in all three.
Shade is no problem at all if green is the look you want. A nandina tucked under a tree or set against a north wall stays leafy and calm year-round. You trade the fall fireworks for steady green, and that suits plenty of yards. The plant itself does not suffer in the lower light. It just grows a touch taller and thinner as it stretches toward the brighter sky, and the cane-like stems space out more.
There is a middle path too, and I lean on it for tricky spots. Part shade, maybe four or five hours of sun, gives you a mixed display. Some leaves blush red while others stay green, which reads softer than a wall of bright color. That blend looks at home in a woodland border or a side yard that only gets morning sun. You still get a hint of the seasonal show without committing the plant to a full-sun bed.
Plant for the color you want, not for some single perfect spot. Want a burst of red each winter? Pick the sunniest open bed you have and let the plant run with it. Want quiet green to fill a dim corner near the house? Shade handles that job well. Your nandina stays healthy across that whole range. That wide tolerance is a big reason it has hung on in so many older yards.
Read the full article: Nandina Domestica Care and Cultivar Guide
