Do you cut seed potatoes?

QUESTION: How do I plant potatoes? Do you cut seed potatoes? Do you have to cut potatoes before planting? -Tom L.

ANSWER: These are two common questions when it comes to planting seed potatoes and whether or not gardeners should cut them.

If your seed potatoes are especially small, you can plant them whole, but most of the time, seed potatoes should be cut into chunks that have at least two eyes each. Cutting up your seed potatoes helps you make the most of the seeds you have and maximize your crop. Don’t make them too itty bitty, though, or they won’t have enough starch to act as a starter food supply for your potato plants.

Each chunk of seed potato you prepare for planting should be roughly square in shape and weigh between one and a half and two ounces. You can eyeball the size of your seed potato chunks if you aim to cut them into pieces about the size of an ice cube. When you cut your seed potatoes into chunks, the potatoes you harvest will be larger. On the other hand, large seed potatoes tend to develop into plants that bear lots of small or medium potatoes.

Do you have to cut potatoes before planting?

You do not have to cut your seed potatoes into pieces before you plant them, especially if they are particularly small, but most gardeners do cut their seed potatoes into pieces that have two eyes each. However, don’t cut your potatoes into pieces that are too tiny, or the seed potato won’t have enough starch to act as a food supply for the plant. The best seed potato chunks are a square shape and weigh between one and a half and two ounces—roughly the size and shape of an ice cube. Remember large seed potatoes, like those planted whole, tend to grow into plants that create lots of potatoes, but ones that are small or medium. Smaller chunks of seed potatoes may make fewer tubers per plant, but the ones you do harvest will be larger. Also, the more seed potato chunks you start out planting, the more potato plants you’ll have, and the more potatoes you’ll end up harvesting.

You’re likely to hear conflicting advice about whether you should plant seed potatoes immediately after cutting them into chunks or whether you should let them cure for a while. Especially if you’ll be planting your seed potatoes in early spring, when it’s cooler and moister outside and conditions make potatoes more susceptible to rot, the curing step is important. When you plant in early spring, let your seed potatoes cure for two or three days in a humid spot where the temperature hovers around 70 degrees Fahrenheit. Curing helps the potatoes develop a protective coating across the surfaces where you’ve cut them.