How to Grow a Potato Plant in Water

Young students often participate in a grow a potato in water experiment in school, and you can also do it at home without much effort. Your observations of growing a potato in water can be recorded to teach kids about plant growth. Potatoes can also be planted in containers and in the ground outdoors.

Potatoes (Solanum tuberosum) are botanically categorized as vegetables, but they grow differently from leafy green ones. Instead, potatoes tend to form underground as part of the plant's roots, which is why they are known as tubers. Potato tubers are modified stems that are loaded with starch-storing tissues, and each one has buds (sometimes referred to as eyes) that can grow into a brand-new plant.

How can potatoes sprout without soil, though? These hardy veggies have enzymes that convert their starch into sugar and produce sprouts that grow out of their eyes. If you want to know how to grow a potato in a jar, all you need is a few toothpicks and water for this remarkable experiment. You can do this with any kind of potato that you eat. This includes sweet potatoes, which are not actually related to the potato but still grow in a similar way.

Stick four toothpicks into the middle section of a medium-size potato that is clean and healthy and doesn't have large eyes formed yet. Space the toothpicks evenly, leaving them sticking halfway out. Lower it into a jar or clear plastic cup with the widest end of the potato down and the toothpicks supporting it on the rim. You'll want to pour in just enough water to cover the bottom of the potato; it should be about an inch and no more.

You'll want to put the potato project in a cool, dark place for one to two weeks until the eyes form, and the sprouts should start to grow around the same time. Now, you can move the whole thing onto a sunny window ledge. The potato will start forming roots and shoots before you know it. You can add more water as needed and transplant it outside when the roots are well established. You've successfully completed your grow potato in water experiment.

To grow potato plants in indoor containers, choose a 2.5 gallon (or larger) tall gardening pot with drainage holes. Add 3 to 4 inches of grainy potting soil; potato plants prefer soils that are a bit more acidic. Place two to three potatoes right on top of the soil with the most productive sprout pointing up. Add another 2 inches of soil on top of your potatoes.

Now, water the soil to moisten it; it shouldn't be wet or soggy. You should place it somewhere in your home that gets several hours of light daily unless you have a greenhouse. Keep the soil consistently moist and water slightly as needed every two to three days. When you start seeing plant growth, mound up some soil around each stalk. If you want to add fertilizer, you'll need to dilute it because these plants don't need much to grow.

Once the plant foliage starts yellowing, the potatoes will be close to ready. Wait until the plants have died because the spuds will be larger. Rub your thumb against the skin and if it stays put, the tuber should be ready to harvest. You can also plant cut potatoes in garden beds, in hilled rows, on raised beds and even covered with straw. You should plant them in the early spring, and you can follow the same directions for planting them in containers.