Important Poison Warning!!!The green sprouts growing from the potato are extremely poisonous. They contain a toxic nerve agent that can kill you. As any parent will tell you, kids eat plants. If you have any children in your household, it is strongly recommended that you:
- Read this page at the federal website, MedlinePlus.
- Abort this project.
How to Grow a Potato in Water
First, find yourself a nice, fresh, large potato at your grocery store.
Position the potato on end halfway into a container at least as tall as the potato. If it looks like a nice fit with lots of room under the potato and some room around the sides of the potato, take potato out and stick some toothpicks (or whatever) around the middle of the potato. The objective of the toothpicks is to extend beyond the container rim and support the potato above the bottom of the container. Reinsert the potato.
Add water. Treat as you would most indoor houseplants.
White roots will start to grow in the water. Green sprouts or vines will start to grow in the air. Keep the potato watered as needed. Eventually you will have a full-blown plant to deal with. You will see vines or leaves. Vines like to cling to things, so position your potato adventure accordingly. As an example, you don't want the vines and your kitchen curtains to become new, best friends.
When the potato plant is on the verge of outgrowing the container, it's time to plant it in a regular plant pot with your favorite mulch. Treat the roots as delicately as possible when making the transfer. The container must be large enough to bury the entire potato on end with all of the green leaves/vines above ground.
If your potato has gone the vine route, come up with something you can place next to the container for the vines to cling to. Continue to regularly water and watch the plant continue to grow.
You've got yourself a new houseplant. As long as the thing doesn't turn into a Triffid, you should be ok.