Did You Know You Can Grow a Sweet Potato in Water – and Get a Dozen New Plants for Free? Here's How in 7 Easy Steps

I love regrowing vegetables; there is immense satisfaction from getting another crop from homegrown produce. It has led me to regrow lettuce, leeks, and onions from scraps over the year, but my newest find is a bit different. It is growing sweet potato slips in water.

Slips are the shoots of a mature sweet potato, and you grow new plants from these. While potatoes are grown from seed potatoes, sweet potatoes are grown from slips. You can buy slips in the spring, or grow your own by suspending a sweet potato in water. It requires patience, but the reward is that you can get lots of slips for a little effort.

You can go from having a sweet potato to many new plants in as few as seven steps, and it is free, plus you only need a few common household items to grow a sweet potato in water. Let’s see how simple it is to grow sweet potatoes in this way.

How to Grow a Sweet Potato in Water

Growing a sweet potato in water is simple, and it differs from growing other vegetables from scraps in the same way.

With many others, such as growing lettuce from scraps or regrowing leeks, you get a quick second crop of leaves or stems.

But with sweet potatoes, you grow slips, aka seedlings. It is a longer-term process, but you can get a dozen or more slips from one tuber using this technique. This means many new plants for free and a bumper harvest of sweet potatoes.

If you want to save time, which is often understandable, you can choose from a range of sweet potatoes to grow at Burpee Gardening and plant them directly into your garden in spring.

How to Grow Sweet Potato Slips in Water: 7 Steps

It can take 10-12 weeks in total from putting the sweet potato in water to the resulting slips being ready to plant into the vegetable garden.

When you buy slips, you cannot plant sweet potatoes until the risk of frost has passed, so plan your timing carefully when growing your own.

To get the process started at the right time, count back 10-12 weeks from the usual last frost date for your US hardiness zone.

1. Prepare the sweet potato - You can sprout sweet potato slips from last year’s homegrown sweet potatoes, or from organic sweet potatoes purchased from a store or farmers' market. There are risks to using any non-organic shop-bought sweet potatoes, as some grocery store vegetables are treated with chemicals to inhibit sprouting. The prep is as easy as rinsing your chosen sweet potato ahead of use to remove any old soil that may contain bacteria.
2. Know your ends - This may sound basic, but trust me, it is crucial. You want to identify the two different ends of the potato. The pointy end of the sweet potato is the bottom, where roots will grow, and the rounder end is the top, where the slips sprout from. It is important to know the difference between the two ahead of the next step.
3. Suspend the sweet potato in water - Take a clear container, such as a glass jar or plastic see-through pot with no holes in the bottom (such as these reusable plastic tumblers at Amazon), and fill it partway with water. Insert three or four toothpicks around the middle of the sweet potato. Then rest the toothpicks on the top of the jar. The bottom (the pointy end) of the tuber is submerged in the water, and the top (the rounder end) remains dry and sticking out of the top of the container.
4. Keep the container somewhere warm - The container should be put in a warm spot where it can get light and temperatures of 65-80°F. This can be on a sunny windowsill or in a warm greenhouse, porch, or sunroom.
5. Change the water - To keep the sweet potato healthy, changing the water every three days prevents any harmful bacteria from building up. Regularly check to ensure the base of the sweet potato remains submerged. Top up the water as required.
6. Watch roots and shoots develop - The first roots should start showing in just a few days, followed a week or two later by green shoots emerging from the top of the sweet potato. It can take 4-6 weeks for the slips to get a few inches long, at which point they are ready to be removed from the sweet potato.
7. Remove the slips - Once the slips reach 4-6 inches long, they can be twisted off the potato or cut off with a sharp knife. These slips are then put in another separate jar of water, though you can have multiple slips in one container to save lots of pots taking up an entire windowsill. Again, refresh the water regularly and watch these slips develop their own roots over the next few weeks.

When your sweet potato slips have roots that are 1-2 inches long, they can be planted out into your vegetable garden or into pots for a vegetable container garden.

Plant them four inches deep and at least one foot apart in a sunny spot in the garden. Or you can grow sweet potatoes in a container using a large pot, bucket, or grow bag, filled with a quality potting soil, such as this Miracle-Gro potting mix available at Amazon.

When you know how to grow a sweet potato in water, you can propagate slips every year. It is the simplest way to propagate sweet potatoes, as the alternative is to grow them from stem cuttings. That is certainly not the traditional way to grow plants, but it is doable.

Indeed, there are more vegetables you can grow from cuttings than most gardeners realize. The common way is to buy seeds or transplants, while plant cuttings are more traditionally done with shrubs, trees, or perennials.

If you are intrigued by propagating veg in unorthodox ways, this guide to vegetables to grow from cuttings reveals 10 crops you can experiment with, including sweet potatoes, and a few tips to help you on your way.