When To Harvest Potatoes

Knowing when to harvest potatoes is the key to getting the best flavor and storage life from your crop. Getting the timing right means the difference between tender new potatoes and hearty, long-lasting maincrop spuds.

This guide will walk you through the simple signs to look for, whether you’re after an early summer treat or your winter supply. Let’s get straight to the signals your plants give you.

There isn’t a single calendar date for harvesting. The best time depends on the type of potato you planted and what you want from your harvest. The two main categories are “new” potatoes and “maincrop” potatoes.

Signs Your Potatoes Are Ready to Harvest

Your potato plants will tell you what they need. Watch for these visual clues above ground.

Flowering: The appearance of flowers is a good early indicator that small, “new” potatoes have formed under the soil. This is your first chance to sneak a few.
Foliage Dies Back: For mature potatoes, the most reliable sign is the natural yellowing, browning, and dying back of the leaves and stems. The plant is finishing its cycle.
Skin Set: For storage potatoes, the skins need to thicken. You can check by gently rubbing a test potato; if the skin slips off easily, it’s not ready for storage.

Harvesting New Potatoes vs. Maincrop

Understanding this difference is crucial for your timing.

Harvesting New Potatoes (Early Season)

New potatoes are a summer delicacy—small, tender, and thin-skinned. They are harvested early, before the plant is fully mature.

Timing: Start checking 2-3 weeks after the plants stop flowering.
Method: Gently dig around the edges of the plant with your hands or a garden fork, feeling for tubers. Take only what you need, and the plant may continue producing.
Use: Eat them soon after harvest. Their thin skins mean they don’t store for long.

Harvesting Maincrop Potatoes (For Storage)

These are your classic, full-sized potatoes meant to last through fall and winter.

Timing: Wait until the plant’s foliage has completely died back, turning brown and dry. This usually happens in late summer or early fall.
Critical Step: After the tops die, leave the potatoes in the ground for another 10-14 days. This allows the skins to toughen up, which is essential for preventing damage and rot during storage.

A Step-by-Step Guide to Digging Up Your Spuds

Follow these steps for a successful, undamaged harvest.

Choose a Dry Day: Harvest when the soil is fairly dry. Wet soil clumps and can hide potatoes, and it increases the risk of disease.
Cut Back Foliage: If you haven’t already, use shears to cut off the dead brown stems a few inches above the soil. This makes digging easier.
Loosen the Soil: Insert a garden fork or shovel well away from the base of the plant—about 10-12 inches out. Gently lift the soil to bring the tubers to the surface.
Hand-Dig for Safety: After lifting, use your hands to sift through the soil and find all the potatoes. Forks and shovels can easily pierce and damage them.
Leave Them to Dry: Lay the harvested potatoes on the dry soil for a few hours. This lets the surface moisture evaporate and any soil to dry for easy brushing off. Don’t leave them in direct sun for more than a few hours, though, as they can sunscald.

Curing and Storing Your Harvest

Proper aftercare is what makes your maincrop potatoes last. This process is called curing.

Curing: Move your dried potatoes to a dark, well-ventilated, and cool place (about 60-65°F) for 1-2 weeks. This further toughens the skins and heals minor nicks.
Sorting: Before final storage, sort through your potatoes. Any that are damaged, cut, or have soft spots should be set aside to eat first. Only perfect, unblemished spuds will store well for months.
Long-Term Storage: The ideal storage conditions are total darkness, good humidity, and a steady temperature of 40-50°F. A basement, root cellar, or unheated garage in a breathable box or sack works well. Check them periodically for any that might start to rot.

Common Mistakes to Avoid

A little care prevents a lot of dissapointment.

Harvesting Too Early: If the skins rub off, you’ve dug too soon for storage potatoes. Their shelf life will be very short.
Using a Fork Carelessly: Stabbing potatoes is the biggest cause of harvest damage. Always dig from a distance and use your hands.
Skipping the Curing Process: Putting uncured potatoes straight into cold storage leads to quicker spoilage and moisture loss.
Storing Near Onions or Fruit: Onions and some fruits (like apples) release gases that can cause potatoes to sprout prematurely.

FAQ: Your Potato Harvest Questions Answered

Can I harvest potatoes after the plant has flowered?
Yes! Flowering signals that early, new potatoes have formed. You can start carefully harvesting a few at this stage for an early treat.

What happens if I harvest potatoes too late?
If left in wet ground too long after the tops die, mature potatoes can start to rot or be damaged by pests like slugs. In very cold climates, they can also be frosted.

How do I know if my potatoes are still good after harvest?
Good storage potatoes are firm, with no soft spots, green tint, or excessive sprouts. A musty smell or wrinkled skin are signs they are past their prime.

Can you eat potatoes right after harvest?
Absolutely, especially new potatoes. For maincrop potatoes, they are edible immediately, but their flavor and texture often improves after a short curing period.

Why are some of my potatoes green?
Green skin indicates exposure to light, either in the garden or after harvest. This produces a bitter substance called solanine. It’s best to peel away all green parts or discard severely green potatoes.

By following these simple guidelines and watching your plants, you’ll master the perfect timing for your potato harvest. A little patience leads to a bounty that can feed you for months to come.