Knowing when are potatoes ready to pick is the key to a successful harvest. Get the timing right, and you’ll be rewarded with spuds that store well and taste fantastic. This guide will walk you through the clear signs, from the tops to the tubers themselves.
Harvesting potatoes isn’t a one-day event. Different types mature at different speeds, and you can even collect some early as a special treat. We’ll cover how to handle new potatoes and storage potatoes, ensuring you get the most from your crop.
When Are Potatoes Ready To Pick
This is the main question for every potato grower. The answer depends on what you planted and what you want from your harvest. Generally, look for both above-ground and below-ground clues.
Signs in the Foliage (The Tops)
The plant’s leaves and stems give the first big hint. After a period of vigorous growth, the plant will start to senesce, or die back. This is a natural process where the plant sends its final energy down to the tubers.
- Flowering: While not a perfect indicator, the appearance of flowers often signals that early tubers are forming underground. For new potatoes, this is your first cue.
- Yellowing and Browning: The most reliable sign for maincrop potatoes is the foliage turning yellow, then brown, and finally wilting. When about half to two-thirds of the tops have died back, your spuds are likely ready.
- Stems Fall Over: The stems will become limp and collapse. This is the plant telling you its work is mostly done.
Signs in the Tubers (The Underground Test)
You can do a gentle investigation to confirm what the foliage is telling you. This is called “grabbling.”
- Carefully move some soil aside at the base of a plant with your hands or a small trowel.
- Feel for a tuber. Gently rub it with your thumb.
- If the skin is very thin and rubs off easily (like a sunburn), the potatoes are too young. If the skin feels firm and doesn’t scrub off, they are maturing nicely.
This test prevents you from accidentally harvesting to early. Mature, set skins are crucial for storage.
Days to Maturity: A Rough Timeline
Check your seed potato variety for its typical “days to maturity.” This is a helpful guideline, but weather and conditions can change it.
- Early Varieties (like ‘Red Norland’): 70-90 days. Best for new potatoes.
- Mid-Season Varieties (like ‘Yukon Gold’): 90-110 days. Good for both new and storage.
- Late (Maincrop) Varieties (like ‘Russet’): 110-135 days. The classic storage potatoes.
Harvesting New Potatoes vs. Storage Potatoes
Your harvesting technique changes based on your goal.
For Tender New Potatoes
You can start harvesting these delicate, thin-skinned treats about 2-3 weeks after the plants stop flowering. The foliage will still be green.
- Gently dig near the edge of the plant with your hands or a garden fork.
- Feel around for smaller tubers and carefully detach them.
- Only take what you need for a meal or two, as they don’t store well. The plant will continue to produce more tubers.
For Storage Potatoes (Maincrop)
This is the final harvest for potatoes you plan to keep over winter. Wait for the foliage to fully die back.
- Cut the dead foliage down to about 2 inches above the soil. Do this 1-2 weeks before digging. This helps harden the skins and prevents disease from spreading from the leaves to the tubers.
- Choose a dry, sunny day to dig. Wet soil can lead to rot, and wet skins are more easily damaged.
- Loosen the soil carefully several inches away from the plant center with a digging or spading fork. Insert the fork at an angle to avoid spearing tubers.
- Lift the plant gently and sift through the soil with your hands to find every last potato. Even small ones left behind can become weeds next year.
Curing and Storing Your Harvest
What you do after picking is just as important. Proper curing heals minor nicks and prepares potatoes for long-term storage.
- Brush Off Soil: Gently remove loose dirt. Do not wash them with water.
- Cure: Place the potatoes in a single layer in a dark, well-ventilated, humid place (like a garage or shed) at 50-60°F (10-15°C) for 10-14 days. Their skins will thicken further.
- Store: After curing, move them to a permanent storage spot. It must be dark, cool (38-40°F / 3-4°C is ideal), and have moderate humidity. Use breathable bags, boxes, or baskets. Check them occasionally, removing any that have gone soft or sprouted.
Common Harvesting Mistakes to Avoid
A few simple errors can ruin a good crop. Here’s what to watch out for.
- Digging Too Early: Thin skins won’t protect the potato, leading to quick spoilage. Always do the skin test.
- Using a Shovel Incorrectly: A straight-down stab with a shovel is a great way to slice potatoes in half. Use a fork and work from the side.
- Leaving Potatoes in the Sun: Freshly dug potatoes can sunburn (turn green) in as little as 30 minutes. Green potatoes contain solanine, which is bitter and toxic. Get them out of the light immediately.
- Washing Before Storage: This removes the potato’s natural protective coating and invites rot. Only brush off dry dirt.
- Storing Damaged Spuds: Eat any cut or bruised potatoes first. They won’t store well and can spoil others.
FAQ: Your Potato Harvest Questions
Can I harvest potatoes after the plant has flowered?
Yes, but likely only as new potatoes. Flowering signals the start of tuber formation, but they need more time to reach full size for storage.
What if my potato plants never flowered?
Some varieties flower minimally or not at all. Rely on the days-to-maturity estimate and the die-back of the foliage as your main guides instead.
My tops were killed by frost. Are the potatoes okay?
Usually, yes. If a frost kills the foliage, simply cut it away and wait about 10-14 days for the skins to set underground before you dig them up. The tubers are protected in the soil.
How long can I leave potatoes in the ground?
Once the tops are dead, you have a window of about 2-3 weeks in dry soil. In wet or cold soil, its best to dig sooner to prevent rot or damage from freezing. Don’t leave them to long.
Why are my harvested potatoes so small?
Small potatoes can result from overcrowding, not enough water during tuber formation, excessive heat, or soil that’s too compacted. Ensure proper spacing and consistent moisture.
Can you eat potatoes right after harvest?
Absolutely! New potatoes are a summer treat. Even maincrop potatoes can be eaten immediately, but their flavor and texture often improves after a short curing period.
With these tips, you’ll confidently know the perfect moment to start digging. Paying attention to your plants and the calendar will lead to a bountiful, usable harvest that can feed you for months to come. Remember, the key is patience—letting those skins harden makes all the difference between a short-lived and a long-lasting stash of homegrown potatoes.