Potato Plant in Jar: Regrow Groceries With Zero Gardening Skills

Growing potatoes in a jar turns grocery store scraps into lush green plants with just sunlight and a little patience. 🌱 I’ve regrown potatoes this way three times—each time watching those stubby sprouts turn into a tangle of vines—without any fancy tools or green thumbs required. The best part?

You can do it on a kitchen counter, windowsill, or even a balcony with just a jar, soil, and a potato you’d normally toss. All you need is a clear jar, potting soil, a potato with at least one "eye" (that’s the little dimple where sprouts appear), and water.

No special soil mixes or expensive setups—just what you’d find at the hardware store. The process takes about 6-8 weeks from sprouting to transplanting, and you’ll end up with a sturdy plant ready for your garden or a container.

You’ll know it’s working when those first pale green leaves unfurl, followed by thicker stems that look like tiny trees. The roots will fill the jar, and by then, you’ll have a head start on next year’s harvest.

Plus, it’s a great way to teach kids (or skeptical spouses) how plants grow from something as simple as a potato. The biggest mistakes are overwatering—soil should stay damp but not soggy—or using a potato that’s already sprouted too far along.

Stick with organic potatoes, and you’ll avoid chemical treatments that could stunt growth. Ready to turn that forgotten potato into a thriving plant?

What you need

Step-by-step instructions for regrowing potatoes in a jar

Here's how to turn grocery store potatoes into a thriving plant with just a jar and a little patience.

Pick a potato with sprouts (eyes) already growing—these are the key to regrowth. Organic potatoes work best since conventional ones are often treated to prevent sprouting. I like to use Russet or Yukon Gold because they sprout reliably. Rinse the potato gently under water to remove any dirt, but don’t scrub off the sprouts.

Place the potato in a clear glass jar (like a mason jar) with the sprouts facing upward. The jar should be wide enough to hold the potato without it touching the sides—this prevents rot. If your jar is narrow, use a smaller potato with just 1-2 healthy sprouts. The goal is to let those sprouts see light while keeping the potato stable.

Fill the jar with room-temperature water until it covers the bottom half of the potato—just enough to keep the base moist but not submerged. The sprouts should stay dry. Change the water every 2-3 days to prevent bacteria buildup. You’ll see the sprouts grow faster when the water stays fresh and clear.

Place the jar in a bright spot—near a sunny window works, but avoid direct afternoon sun, which can overheat the jar. A south-facing window is ideal. If your light is weak, supplement with a grow light 6-8 inches away for 12-14 hours daily. Watch for the sprouts to turn green and leafy—this means they’re photosynthesizing and ready for the next step.

After 2-3 weeks, the potato will develop white roots and green stems. This is your signal to start prepping for soil. The roots should be 1-2 inches long, and the stems should have 2-3 sets of leaves. If the water gets cloudy or smells funky, dump it and rinse the jar before refilling—this keeps your plant healthy.

At this stage, you can either plant the whole jar in soil (burying it halfway) or transplant the potato into a pot with potting mix. I prefer the latter because it gives the roots more room to spread. Fill a 6-inch pot with well-draining soil, make a small hole, and gently place the potato in so the roots stay covered but the top is exposed.

Water the potted potato lightly at first—just enough to keep the soil moist but not soggy. Overwatering now will rot the delicate roots. Place the pot in bright, indirect light for a week to help it adjust. After that, move it to full sun (6+ hours daily) to encourage strong growth. You’ll see new leaves emerge within 5-7 days—that’s your reward for patience!

Fertilize once a month with a balanced liquid fertilizer (like 10-10-10) to boost growth. By 6-8 weeks, your potato plant will be 2-3 feet tall with multiple stems. If flowers appear, you can let them pollinate (though store-bought potatoes often don’t produce edible tubers). The real treasure? The new potatoes that form along the stems—harvest them when they’re golf-ball sized for the best flavor.

Tips & tricks for perfect potato plant in jar

A few simple tricks will help you avoid common pitfalls and keep your potato plant thriving from start to finish.

Potato Selection: Look for potatoes with sprouts that are at least 1/4 inch long—these are the most vigorous starters. If your sprouts are tiny, give them a head start by placing the potato in a paper bag with an apple (the ethylene gas helps them grow faster). Avoid potatoes with sprouts that are shriveled or black, as these won't grow well.

Jar Stability: If your jar isn't wide enough to hold the potato without it touching the sides, prop it up with a small piece of cardboard or a folded paper towel. The potato should sit snugly but not tightly—this prevents rot while keeping it stable. I've seen potatoes tip over in narrow jars and get waterlogged, so this little adjustment saves a lot of frustration.

Lighting Strategy: For the 12-14 hours of grow light mentioned, position the light so it's 6-8 inches away from the jar—any closer and it can scorch the leaves. If you notice the leaves turning yellow or curling, move the light back slightly. A simple LED grow light works perfectly, but even a regular desk lamp with a full-spectrum bulb can work in a pinch. Just keep an eye on the leaves for signs of stress.

Transplanting Tip: When it's time to move your potato to soil, gently rinse the roots to remove any water residue. This helps the roots acclimate to the drier soil environment. If the roots look tangled or matted, carefully tease them apart before planting—this gives them room to spread in their new home. I always use my fingers to create a loose nest of soil around the roots to encourage quick establishment.

Frequently asked questions

Got questions about growing a potato plant in a jar? You’re not alone! Here are some of the most common queries—and their easy answers—to help you succeed without the stress.

How long does it take for a potato to sprout in a jar?

With the right conditions (warmth, indirect light, and patience), you’ll see tiny sprouts—called eyes—emerge in 2 to 4 weeks. Keep the jar in a bright spot (like a sunny windowsill) and avoid direct sunlight, which can overheat the jar. If sprouts don’t appear after 4 weeks, try rotating the jar or adding a little more water to the base.

How often should I water the potato in the jar?

Water your potato every 3–5 days, but never let it sit in standing water—root rot is a real risk! Check the moisture by touching the soil: if it’s dry 1 inch down, it’s time to add a splash. Use room-temperature water to avoid shocking the potato. Pro tip: Tilt the jar slightly to prevent water from pooling at the base.

Can I use any potato to regrow, or are some better than others?

Not all potatoes are created equal! Opt for organic, untreated potatoes with firm, unbruised skin and visible eyes (the little dimples). Russets, Yukon Golds, and red potatoes work best. Avoid pre-sprouted potatoes from stores (they’re often chemically treated to prevent sprouting) and never use sweet potatoes—they won’t regrow successfully.