How fast does that grow?
Growth rates span nine orders of magnitude, from bamboo you can watch move to trees you cannot.
2 × a grass
10 mm is faster than 4 of the 7 references on this page.
Reference figures are measurements and are rounded; the unit conversion behind them is exact.
| Reference | Size | Yours ÷ theirs | Note |
|---|---|---|---|
| fingernails | 0.1 mm | 100× | About 3.5 mm a month |
| hair | 0.35 mm | 28.6× | About 1 cm a month |
| an oak tree | 1.4 mm | 7.14× | Half a metre a year |
| grass | 5 mm | 2× | |
| sunflower | 30 mm | 0.333× | |
| a giant kelp | 600 mm | 1/60 | |
| bamboo | 910 mm | 1/91 | Up to 91 cm a day |
Worth knowing
- Some bamboo species grow 91 cm in a day — nearly 4 cm an hour, fast enough to see over an afternoon.
- Human hair grows about 1 cm a month, so a shoulder-length head of hair represents roughly three years of growth.
Frequently asked
What is the fastest-growing plant?
Certain bamboos, at up to 91 cm a day. Giant kelp is close behind at 60 cm a day and is the fastest-growing organism in the sea.
How fast does hair grow?
About 0.35 mm a day, or 1.25 cm a month, though it varies with age, health and site on the body. Growth is not continuous — each follicle cycles.