How does light affect photosynthesis?

As I’m sure you know, plants perform photosynthesis via chlorophyll, and I’m sure you also know that chlorophyll is green, giving leaves their characteristic color. But have you ever noticed that shade-loving plants are usually darker green than plants that thrive in the sun? That’s because the more chlorophyll a plant has in its leaves the darker green it will be.

Shade plants, often native to tropical regions where they grow as understory plants, need quite a bit more chlorophyll to produce a sufficient amount of sugars to feed themselves and grow.

While plants that grow in full sun don’t need much chlorophyll at all, by comparison, since sun is plentiful, so they tend to be lighter green overall. While this isn’t a hard and fast rule, it is pretty common.

For example, compare a corn plant, with its yellow-green leaves, to a Hosta or cast-iron plant. The difference in greens is striking.

Shade plants also don’t flower as much as plants that prefer full sun, or their flowers are less significant, since sufficient sunlight is necessary to produce showy flowers.

A sun plant when placed in a shady spot will often not flower, and may be lanky an unattractive, since it will try to stretch up in search of sunlight.

Variegation is also common in shade plants: those white-striped areas on variegated leaves lack chlorophyll.

And colors other than green are also more common in shade plants, indicating a different strategy altogether, where the plant may have replaced much of the chlorophyll with carotenoids and anthocyanins, giving them orange or purple characteristics.