Potatoes are one of the easiest crops to grow producing a bounty of tasty tubers when planted in garden beds and containers. Plus, there’s so many awesome potato varieties to grow – from fingerlings to russets – in a rainbow of colors. But as the crop is produced below ground, it’s hard to tell when the tubers are ready to dig. So, how DO you know when to harvest potatoes?
When to harvest potatoes?
Harvesting potatoes is so much fun, even the kids will want to help. It’s like digging for buried treasure – treasure you can eat! There are two main types of potatoes: new potatoes and storage potatoes, and both harvesting time and techniques differ between the two types. Because I want both new potatoes for summer cooking and storage potatoes for fall and winter, I plant at least one bed of each. Figuring out when to harvest potatoes can be a challenge for new gardeners, but once you know the basics, timing the harvest is a snap!
New Potatoes – All potatoes can be new potatoes if harvested when the tubers are still small and thin-skinned, about 50 to 55 days from planting for early maturing varieties. The first sign that new potatoes have formed is the appearance of the flowers. At that point, feel free to start harvesting.
Storage Potatoes – Storage potatoes, also called main-crop potatoes, are ready at the end of the growing season when the foliage has turned yellow and begun to dry. Some gardeners cut off the foliage while others allow it to die back naturally. Either way, the tubers need to be left in the ground for about two more weeks. This allows the skins to thicken up, which results in better storage quality.
How to harvest potatoes
Pick a dry day to harvest potatoes as moisture can spread disease and rot. What’s the best way to harvest? Carefully! Try to avoid piercing or slicing the potatoes when digging the tubers. If your spade does slip, eat damaged potatoes right away. I find it handy to keep a bowl nearby for damaged tubers which then head directly to the kitchen.
New Potatoes – When the plants begin to flower you can start harvesting new potatoes by reaching into the side of the hill and taking a few tubers from each plant. I use a gloved hand, not a tool, for this task as I don’t want to damage the plants and I want to keep my hands (relatively) clean. Once you’ve harvested a few new potatoes, push the soil back in place and mound it around the plants.
If harvesting new potatoes from a container or potato grow bag, reach into the soil to feel around for the tubers, taking just a few from each plant at any one time. After harvesting new potatoes from in-ground or container plants, feed them with a fish emulsion fertilizer to encourage healthy growth and more tubers.
Storage Potatoes – To harvest storage potatoes, insert a garden fork about a foot away from the plant and gently lift the root mass. There may still be a few potatoes in the ground, so use a gloved hand to feel around for any missed tubers. Once harvested, gently brush off caked on soil and allow them to dry off for an hour or so outdoors. Do not wash the tubers.
Container grown storage potatoes can be easily harvested by dumping the container onto a tarp or in a wheelbarrow. Sift through the soil with your hands to grab all of the tubers.
How to store potatoes
Before they can be stored, potatoes need to go through a curing process. This helps the skin thicken up and extends the storage life of the tubers. To cure potatoes, lay them on newspaper, trays, or cardboard in a cool, dark spot (50 to 60 F, 10 to 15 C) with high humidity for one to two weeks. Pick a location that offers good air circulation.
Once cured, move the potatoes (removing any that have signs of damage) to bushel baskets, cardboard boxes (with ventilation holes poked in the sides), low baskets, or brown paper bags. You can also find multiple drawer harvest storage at many garden supply stores. Don’t pile them too deeply, however as that can encourage rot to spread. Cover containers with cardboard or sheets of newspaper to block light.
The storage area should be cooler than the curing site and be dark and well-ventilated. I use a corner of my basement, but a root cellar is best if you have one. Aim for a temperature of 40 to 45 F (4.5 to 7 C) with high humidity. Under ideal conditions, storage potatoes can retain quality for six to eight months. Check tubers regularly and remove any that show signs of rot or shrivelling.
The thin skin that makes new potatoes so appealing limits their storage life to weeks not months. Therefore, enjoy new potatoes soon after harvesting them.
Do you have any tips to add on when to harvest potatoes? Leave them in the comments below.
For more on growing potatoes in a garden, check out these awesome articles:
- Growing potatoes in small spaces with 7 easy steps
- Build a potato bin with compost and autumn leaves