Chlorophyll is the pigment that captures light for photosynthesis. Plants carry chlorophyll a and b, which absorb strongly in the blue (around 430-450 nm) and red (around 640-680 nm) and reflect green. Each molecule has a magnesium atom at its centre, and building it needs nitrogen, magnesium and iron, among other things.
In practice
Leaf colour is largely chlorophyll status: - Pale or yellow older leaves: often nitrogen or magnesium moving to new growth, or natural late-flower senescence. - Pale new growth: often iron, sulfur or root-zone/pH issues. - Dark, glossy green: frequently excess nitrogen.
Chlorophyll breakdown in late flower reveals other pigments (carotenoids, anthocyanins) and is normal, especially with a nitrogen taper.
After harvest, chlorophyll still in the material breaks down during a slow dry and cure. Material dried too fast keeps a green, grassy, hay-like smell. Drying and curing, not flushing, decide that.
Don't confuse with
- Anthocyanin: purple/red pigment in the vacuole, not photosynthetic.
- Carotenoids: yellow-orange accessory pigments.
- Chlorosis: the symptom of losing chlorophyll.
Myth check
"Flushing removes chlorophyll" is a Myth. Chlorophyll is broken down by the plant's own senescence and by a proper dry, not by plain water at the roots. See the flush debate.
