How to Grow Sweet Potatoes in Water
Sweet potatoes are a carbohydrate-rich source of food for millions of people in developing countries. In the US, they are primarily grown for food in USDA Zones 9 to 11. Ornamental varieties may also be grown in containers and taken indoors for the winter. In addition, the vines grow readily in water.
Sweet Potato Basics
Sweet potatoes are a traditional food in many countries because they will grow in poor soil. Although they produce better with regular water, they can handle dry periods. The tubers are usually orange but may also be purple, yellow or white inside. Unrelated to the true yam, these morning glory relatives are sometimes called by the same name.
Since sweet potatoes rarely flower or produce seeds in temperate regions, they are grown from rooted cuttings called slips:
- Select a healthy sweet potato tuber and find a glass container slightly larger than the tuber.
- Place the tuber in the jar, pointed end down, and insert toothpicks around its diameter to hold it in place.
- Fill the jar with enough water to cover the bottom three inches of the tuber.
- Place on a sunny windowsill.
On the Windowsill
In addition to starting sweet potatoes for slips, many people like to grow the vines as indoorplants. You can also just place some rooted slips in a glass jar of water. The edible leaves can be harvested and eaten as you would other cooked greens like kale. Follow the directions for starting slips noted above. Change the water every few days or if it becomes cloudy. Trim back the vine as necessary.
In an Aquarium
Sweet potatoes make good aquarium plants. Their roots will take up nitrates and other waste products in the aquarium, helping to keep the water clean and fish healthier. Use a perforated basket or something similar to suspend the rooted slips several inches below water level. If either the roots or leaves get too long, you can always trim them back.
Hydroponic Sweet Potatoes
Although this is probably not something the average gardener would want to tackle, sweet potatoes can also be grown hydroponically. Researchers began working on this issue a few years ago as sweet potatoes are rich in carotene and a good source of calories and fiber. The plants are grown in typical commercial hydroponic systems and the tubers can be harvested when ready.
Any sweet potato that you have grown in water can also be planted outdoors at the right season. Soils should be lose and friable. You should not plant the vine until at least two weeks after the last expected frost. Most sweet potatoes need 90 to 120 days to produce a crop. Store in a cool, dry place with good ventilation.