What Is the Slowest-Growing Plant?

In general, cactus plants are the slowest- growing plants on earth. One kind of cactus, the saguaro, grows just one inch in the first ten years of its life. The saguaro doesn't grow a branch until it's 16 years old, and after that, it grows just an inch a year.

But some pine trees that live very far north in the cold Arctic or very high up on a mountain can grow even slower than a cactus. One tree, a Sitka spruce, growing in the Arctic, grew only 11 inches in 98 years!

The saguaro doesn't begin to flower until it's about 60 years old!