A rhizome, technically a stem, grows just at the surface, or slightly underground; sending roots down into the soil and leaves up into the light.
Many plants grow from rhizomes.
Have you eaten ginger? Ginger is a rhizome, and the ginger you purchase at the grocery can be planted and grown into a new plant by placing it on the surface of some good dirt, adding just a little dusting of soil on top, and watering it in. Within a few weeks roots will grow and leaves emerge from the piece of ginger rhizome.
Many of the most beautiful Begonias grow from rhizomes.
And like a piece of ginger, the rhizome may go dormant for a period of time before suddenly producing new leaves and beginning to grow.
When you buy a Rex Begonia for its gorgeous leaves, it is growing from a little rhizome.
I purchased this bird’s nest fern and a little Begonia at Lowe’s back in the winter, and potted them up in a big bowl for a winter centerpiece on my dining table. We enjoyed them all winter, but the Begonia struggled along while the fern took off.
I moved them both into a nursery pot and set them outside in early summer. The Begonia had lost its last leaf by this time, and I had no way to tell whether it was alive or dead.
But look! The rhizome survived, and has begun to grow again and produce new leaves.
Here is another rhizomatous Begonia which has gone completely dormant twice now, and then has suddenly sprung back into growth.
I love the leaves on this one for their silvery sheen.
Rhizomatous Begonias grow extremely well in the shade. That said, they grow much better outside than inside.
Many of these special Begonias are winter bloomers, and will begin blooming, when they are happy, in January or February. They need bright light inside to bloom, but love a shady and sheltered spot outside in the summer.
We had actually given up on this one for dead last spring, and chucked the contents of its pot under a shrub. I was thrilled to find it alive and leafing out several weeks later.
It grew happily under an Azalea all last summer, and survived most of the winter potted, indoors by a window.
By April it looked like it was dieing back, and so I moved it outside, and out of its pot, into the Earth. It perked up within a few weeks, and looks lush and happy again.
Because a rhizome sends out both roots and stems, it can be broken into smaller pieces and each replanted.
The rhizome grows longer over time, as it stores food for the plant; sometimes branching out to cover more ground. It can grow pretty quickly into a large plant.

A different rhizomatous Begonia at the bottom of the photo, growing with Japanese painted Fern. This rhizome has grown over the edge of the pot. I could break it off and set it into a new pot of soil to root.
Many ferns grow from rhizomes. German Iris grow from rhizomes.

Ginger lily growing from a rhizome given to us by a friend. These can be divided and spread each spring.
Canna lilies and ginger lilies grow from rhizomes.
Plants which grow from rhizomes can be easily divided to increase your stock.
Each little piece of the rhizome has the potential to grow into a new plant identical to the original one.
Most plants growing from a rhizome need to dry out a little between waterings. Too much water can cause the rhizome to rot, which will kill the plant.

Many ferns grow from rhizomes. They spread as the rhizome grows just under the soil level, sending out new roots and shoots as it grows.
Watch the leaves to know when more water is needed, but in general let the surface of the soil dry a bit between drinks. Some, like iris, are very drought tolerant.
A rhizome is a wonderful adaptation which allows a plant to wait out poor conditions without dieing, so it can grow again when conditions improve.
And it is a wonderful thing for a gardener to realize that a plant thought dead was only dormant, and has begun to grow yet again!
Photos by Woodland Gnome 2013-2014
Your begonias are so lovely!
Thank you, Eliza 😉 Seeds in the mail to you today-
Thank you so much! Looking forward to it!
😉