So you have a bag of potatoes you bought from the grocery store and forgot about them. Now, those potatoes have started sprouting and you’re wondering, can you plant sprouted potatoes? We’ve all been there, so let’s find out the answer.
You can successfully grow potato plants from sprouted potatoes bought from the store. Sprouting potatoes are easy to grow in the garden or a pot for a crop of delicious potatoes.
Seed potatoes may work better (for reasons we’ll discuss soon), but if you already have sprouted potatoes, why not plant them? Let’s look at how to plant, grow, and care for sprouted potatoes.
Seed Potatoes Vs. Store-Bought Potatoes
Many gardeners debate whether seed potatoes or store-bought potatoes are better for planting or, indeed, if there is even a difference. But the general consensus seems to be this: there is a difference, and it may or may not affect you.
This biggest difference is in design: grocery store potatoes are designed to be eaten, while seed potatoes are meant for planting. This means that they might have key differences that affect the growth cycle.
For one, some potatoes you find in grocery stores are given some form of sprout inhibitor. This can make it harder for them to sprout, which leads to the potatoes looking appealing for longer. Obviously, this can make it difficult to grow your own.
However, if your potatoes have already sprouted, then it’s likely that they’ll be ok to grow.
The other big difference is that seed potatoes are often bred or treated to be more resistant to disease.
Blight, in particular, can menace potato plants and can be a big risk when using store-bought potatoes.
Blight is a name for a group of diseases that ravage a lot of common garden plants. It first shows up as small brown circles on the undersides of leaves, which will slowly spread and cause the leaves, and then the rest of the plant, to rot.
Blight is very difficult to deal with, and once introduced, can be hard to get rid of. For this reason, many gardeners are scared to bring non-seed potatoes into their gardens, because the risk of blight is high.
If you want to mitigate this risk somewhat, you can grow your grocery-bought sprouted potatoes in pots away from the rest of your garden. Yes, they might still get blight, but it is less likely to spread to your other plants if that does happen.
So, if you’re serious about growing potatoes and want to plan it, seed potatoes are a good option, especially because they’re often not much different in price from grocery store potatoes. But if you have some store-bought potatoes that have sprouted, you can plant them— just keep them away from your other plants if you worry about blight.
Prepare Your Planting Site for Growing Potatoes
If you’ve decided to plant your sprouted potatoes, the first step is preparation.
First, you should choose and prepare a site, so that you have it ready when the potatoes are ready! Choose a place that gets 6-8 hours of full sun every day, with partial shade the rest of the day. Not full shade, as this could stunt the plants and lead to smaller potatoes.
Make sure that the site has well-draining soil, so the potato plants don’t get waterlogged. Once you’ve found a sunny, well-draining spot, you want to prep the soil itself.
Potatoes like fertile soil so you can add compost and aged manure to the soil prior to planting. If you are monitoring the soil pH, they prefer 5.5-7 and you can measure this with a soil monitor here.
Since potatoes grow below ground, they benefit from having a lot of soil. The best way to provide this is to mound the soil— form it into mounds between 8 and 10 inches tall. This way, the plants have more space to spread below ground, and can produce more potatoes.
You can mound the soil in rows, with each row being about one foot apart. You can typically do this with your hands (don’t forget gloves!), but for larger gardens, you can also use a shovel or other tools to help you.
Of course, you might prefer to grow your potatoes in a pot, and this can be done! You still have to make sure it is well-draining, and that the pot is in a location that gets enough light. And since potatoes need a lot of room, you’ll need a big pot: it should be 2 to 3 feet deep and hold at least 10-15 gallons.
For planting in pots, the soil preparation is a little bit different. You want to fill the pot a little more than halfway— you’ll add more soil later on in the growing process.
Preparing Your Potatoes For Planting
Once you’ve prepared the planting site, now you can finally prepare the potatoes themselves!
First, count how many sprouts you have on each potato. Sprouts often grow from “eyes” on the potato— if you have multiple sprouts coming from one eye, count it as one sprout.
While you could just stick the whole potato into the ground, you’ll get much more out of it if you plant each sprout individually. To do this, use a sharp, clean knife to carefully cut each sprout. Leave a little bit of potato attached to the sprout, and remember to keep all the sprouts in one eye together.
Then, you want to leave your freshly cut potatoes somewhere to heal, to help lower the risk of disease. Place them on a clean surface, and leave them to rest (out of sunlight) for 2 to 3 days. This should give them time to callous over, and then they’ll finally be ready for planting!
Plant each sprout 3-4 inches below the surface of the soil, with at least 12 inches between each plant. Plant them sprout-side up, so that they can grow more easily. They might take a few weeks to break through the surface, so now it’s time to be patient!
Caring for Your Potato Plants
Now that you’ve put all this effort into planting your potatoes, it’s time to take care of them! Since you already gave them a sufficiently sunny spot, your 3 biggest worries are going to be water, hilling, and protection from the cold.
Ideal Temperature for Growing Potatoes
First, the cold. Depending on the time of year, this will be the easiest one to deal with. Potatoes don’t like weather that drops below freezing, and anything that causes frosts or makes the ground harder will make it more difficult for them to grow. So when growing your potatoes, make sure to plant them after the risk of frost has passed.
Ideally, potatoes prefer soil temperatures in the range of 60-68˚F (15-20˚C) and with leaf development best at 68-77˚F (20-25˚C). Potatoes will grow either side of these ranges but the temperatures given are the preference for a terrific harvest.
Watering Potato Plants
Then, you need to water your potatoes! When growing, potatoes typically need 1 to 2 inches of water a week. They don’t like to sit in water, but also don’t want to fully dry out. Check the top inch (that’s from the tip of your finger to your first knuckle) with your finger. If it’s dry, give them some water. If not, it’s probably better to hold off.
However, early potato plants are much more sensitive to water and to getting waterlogged. Before the first leaves break the surface of the soil, they won’t need as much water, and too much water could end up killing them. So water less during this period; some gardeners actually don’t water at all until the first leaves appear, but that may not be necessary.
Hilling Potato Plants
Perhaps the most important part of caring for potato plants is hilling. When tubers— the parts of potato plants that grow underground— are exposed to sunlight, they turn green and can produce harmful chemicals. This can prevent the plant from growing as many healthy potatoes!
To help prevent this, you want to “hill” your plants at least once during the growing season. This simply means putting more soil on top of them, so not as much of the plant is exposed. (That’s also why you don’t fill the pot all the way at first if you grow potatoes in pots— so you can hill them later.)
Wait until the stalks of the plant are at least 6 inches above the soil, with some healthy leaves. Then, add more soil onto the plant until only the top sets of leaves are exposed. Make sure not to cover all the leaves, because without them, the plant can’t perform photosynthesis!
If the plant gets very tall again, you could consider hilling once more. However, it’s usually only necessary to hill once in the season to keep the potatoes growing well.
So to recap: make sure your plants get lots of sun, keep them protected from the cold, water them (but not too much!), and hill them once they get big enough. If you do this, you’re well on the way to a bountiful potato harvest!
How Long Does it Take to Grow Potatoes?
Potato plants typically reach maturity 90-120 days after planting (3 to 4 months). This isn’t after the first leaves appear, but after initial planting, so remember that!
Around this time, the leaves will probably start turning yellow, and the plant will begin to die back. Don’t panic! In fact, it’s a reason to celebrate: this means the potatoes are almost ready for harvesting.
See, when potatoes are fully grown, they have no need for the bright green foliage above ground anymore. Instead, they need to focus on toughening up their skin to survive the harvest.
So if your potato plant starts dying back about 3-4 months after planting, it’s probably a good sign.
You can harvest potatoes as little as 2 weeks after the plant starts to die back. Potatoes harvested this early will have softer skins, which means they may be easier to eat but won’t last as long. If you wait another couple weeks, the skins will harden even more, and you’ll have some good, long-lasting potatoes.
It’s also important to note that, much like in their early stages, potatoes don’t need much water near the end of their growth cycle. In fact, any additional water can make it harder for the potatoes to toughen up and possibly harm them, so you should avoid watering them altogether after the plants start to die back.
Harvesting potatoes is easy: you simply dig them up! If you planted them in a pot, you can gently dump out the pot and dig through it to find your harvest. If they were planted in the ground, all you have to do is use your hands (and maybe, carefully, a spade) to dig up your potatoes.
Curing and Storing Potatoes
Once you’ve harvested your potatoes, storing them is easy. They should be cleaned, but once again, water isn’t good for them. Simply brush them off as well as you can with your hand or a towel.
Then, place them in a cool, dry, sun-free place for 2 to 3 days to cure. At the end of this time, the skins should toughen up, and they can be stored wherever you like to store potatoes until you’re ready to eat them.
And the best part? You can repeat the cycle all over again! If you let these potatoes sit until they form sprouts, you can plant them to get even more potatoes! Although you probably won’t need to plant all the potatoes you’ve grown— that might be quite a lot.
So as you can see, planting sprouted potatoes from the store is easy! Potatoes don’t require as much maintenance as some other plants, and their yield can be large. If you’ve got potatoes from the grocery store that have been sitting for too long and have sprouted, consider planting them. Talk about getting more for your money!
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