Potato plants are ready to harvest when their tops have completely died back. Knowing exactly When Are Potato Plants Ready To Harvest can save you from digging up tiny, unusable spuds or leaving them to rot in the ground. This guide walks you through every sign, step, and trick to get your potatoes out at the perfect time.
You don’t need a green thumb to figure this out. Just watch the plants, check the soil, and use a few simple tests. Let’s break it down so you can harvest with confidence.
When Are Potato Plants Ready To Harvest
The short answer is: wait until the foliage turns yellow, wilts, and dies back completely. But there’s more to it than that. Different potato varieties, weather conditions, and your personal preference for size all play a role.
Potatoes are ready for harvest about 10 to 20 weeks after planting, depending on the type. Early-season varieties mature faster, while maincrop types take longer. You can also harvest “new” potatoes earlier, before the plants fully die back.
Key Signs The Plant Is Ready
- The stems and leaves turn yellow and start to flop over.
- The foliage dries out and becomes brown and crispy.
- The skin of the potatoes feels firm and doesn’t rub off easily.
- The tubers are the size you expect for that variety.
Don’t rush. If you dig too early, the skins will be thin and the potatoes won’t store well. If you wait too long, they might sprout or rot in wet soil.
Understanding Potato Growth Stages
Potatoes grow in three main phases. Knowing these helps you time your harvest perfectly.
Phase 1: Planting To Emergence
After planting, sprouts appear above ground in 2 to 4 weeks. The plant focuses on building leaves and roots. No tubers yet.
Phase 2: Vegetative Growth
The plant grows tall and bushy. Underground, stolons form and begin swelling into small potatoes. This is when you can start stealing a few “new” potatoes if you want.
Phase 3: Maturation And Die-Back
The plant stops growing. Leaves yellow and die. The skins on the tubers thicken. This is the signal for main harvest.
Most home gardeners harvest in phase 3. But you can also harvest earlier for fresh, tender potatoes.
How To Check If Potatoes Are Ready
You don’t have to guess. Use these methods to be sure.
1. The Foliage Test
Look at the tops. When 80% to 100% of the foliage has died back, the potatoes are likely ready. For maincrop varieties, wait until the stems are completely brown and dry.
If the weather has been wet, the foliage might stay green longer. In that case, cut the stems down to about 2 inches above the ground. Then wait 2 to 3 weeks before digging. This forces the skins to set.
2. The Dig Test
Gently dig around the base of one plant with your hands or a garden fork. Feel for potatoes. If they are the size you want and the skins don’t scrape off easily, it’s time.
For new potatoes, you want them small and tender. For storage potatoes, you want them full-sized with thick skins.
3. The Skin Rub Test
Rub a potato gently with your thumb. If the skin comes off easily, it’s not ready for storage. If the skin stays put, it’s mature.
This test works best after you’ve dug a sample. Don’t rub too hard or you’ll damage the skin.
Harvesting By Potato Type
Different potatoes have different timelines. Here’s a quick breakdown.
Early Or New Potatoes
These are harvested about 10 to 12 weeks after planting. You don’t wait for the foliage to die back. Instead, dig them when the plants are still green and flowering. The potatoes will be small, thin-skinned, and perfect for boiling.
To harvest new potatoes, gently lift the soil around the base of the plant and pull out the largest tubers. Leave the rest to grow.
Mid-Season Potatoes
These take about 14 to 16 weeks. Wait until the foliage starts yellowing but isn’t fully dead. The skins will be slightly thicker than new potatoes but still tender.
Maincrop Or Storage Potatoes
These take 18 to 20 weeks or more. Wait until the foliage is completely dead and dry. The skins will be thick and tough, perfect for long-term storage.
Maincrop potatoes are the ones you’ll keep for months. They need full maturity to store well.
Step-By-Step Harvesting Process
Follow these steps to avoid damaging your potatoes.
- Stop watering about 2 weeks before harvest. This helps the skins harden and reduces rot risk.
- Cut the foliage if it hasn’t died back naturally. Leave 2 inches of stem above ground.
- Wait 2 to 3 weeks after cutting the tops. This allows the skins to set.
- Dig carefully with a garden fork or shovel. Start at the edge of the hill and work inward to avoid stabbing potatoes.
- Lift the potatoes by hand once the soil is loosened. Don’t pull on the stems.
- Brush off excess soil but don’t wash them. Washing removes the protective skin layer.
- Cure the potatoes in a dark, well-ventilated area for 1 to 2 weeks. This heals any minor cuts and thickens the skin.
- Store in a cool, dark place at about 40 to 50°F (4 to 10°C). Avoid light to prevent greening.
If you harvest in wet conditions, let the potatoes dry on the ground for a few hours before moving them indoors.
Common Mistakes To Avoid
Even experienced gardeners mess up sometimes. Here’s what to watch out for.
- Harvesting too early. You get tiny potatoes with thin skins that don’t store.
- Harvesting too late. Potatoes can sprout, rot, or get eaten by pests.
- Digging with a fork too close to the plant. You’ll stab and ruin many tubers.
- Washing potatoes before storage. Moisture invites mold and rot.
- Storing in light. Potatoes turn green and toxic when exposed to light.
Take your time. A careful harvest gives you better potatoes.
When To Harvest In Different Climates
Your local weather affects when potatoes are ready.
Cool Climates
Potatoes grow best in cool weather. In northern regions, plant in early spring and harvest in late summer or early fall. The foliage will die back naturally as temperatures drop.
Warm Climates
In hot areas, plant in late winter or early spring. Harvest before the heat of summer. The foliage might die back faster due to heat stress. Check the tubers regularly.
Wet Climates
If you get a lot of rain, the foliage might stay green longer. Cut the tops to force maturity. Also, watch for rot. Harvest promptly once the skins set.
Dry Climates
In dry conditions, the foliage will die back quickly. But the tubers might be smaller. Water consistently during growth to get a good yield.
No matter your climate, the same signs apply: yellowing foliage, firm skins, and proper size.
How To Tell If Potatoes Are Ready Without Digging
You don’t always need to dig to know. Use these clues.
- Flowering. For new potatoes, harvest after the flowers appear. For maincrop, wait until flowers fade and the plant declines.
- Soil cracking. As potatoes swell, they can push up the soil. Cracks around the base of the plant mean tubers are growing.
- Stem thickness. Thick, sturdy stems often mean larger potatoes below. Thin, weak stems might mean small tubers.
- Time since planting. Count the weeks from planting. Early varieties: 10-12 weeks. Maincrop: 18-20 weeks.
Combine these clues with a sample dig for the best results.
Harvesting Potatoes In Containers
If you grow potatoes in bags or pots, the process is similar but easier.
When the foliage dies back, simply dump the container onto a tarp. Sift through the soil and collect the potatoes. No digging required.
For new potatoes, you can reach into the soil and pull out a few without disturbing the whole plant. Just be gentle.
Container-grown potatoes often mature a bit faster because the soil warms up quicker. Check them a week or two earlier than ground-grown plants.
Storing Your Harvest
Proper storage keeps your potatoes good for months.
- Cure them first. Keep them in a dark, humid place at 50-60°F (10-15°C) for 1-2 weeks. This heals cuts and thickens skins.
- Sort them. Remove any damaged, green, or soft potatoes. Use those first.
- Store in a cool, dark place. Ideal temperature is 40-50°F (4-10°C). A basement, root cellar, or garage works well.
- Use breathable containers. Burlap sacks, paper bags, or cardboard boxes with holes. Avoid plastic bags.
- Check regularly. Remove any sprouting or rotting potatoes to prevent spread.
Don’t store potatoes with apples or onions. They release gases that cause spoilage.
What If The Foliage Doesn’t Die Back
Sometimes the tops stay green well into fall. This can happen in cool, wet weather or if you planted late.
If frost is coming, cut the foliage down to 2 inches. Wait 2 to 3 weeks, then harvest. The potatoes will still mature underground.
If no frost is coming, you can leave the plants longer. But check the tubers periodically. Overly mature potatoes can become woody or start sprouting.
Another option is to harvest a few plants early and leave the rest. This spreads out your harvest and reduces risk.
Frequently Asked Questions
How do I know if my potatoes are ready to harvest?
Look for yellowing and dying foliage. Do a sample dig to check size and skin firmness. The skins should not rub off easily for storage potatoes.
Can I harvest potatoes before the plants die?
Yes, for new potatoes. Dig them when the plants are still green and flowering. They will be small and tender.
What happens if I harvest potatoes too early?
You get small tubers with thin skins that don’t store well. They are fine for immediate eating but won’t last.
How long after planting are potatoes ready?
Early varieties: 10-12 weeks. Mid-season: 14-16 weeks. Maincrop: 18-20 weeks. Check the seed packet for exact timing.
Should I water potatoes before harvest?
Stop watering about 2 weeks before harvest. This helps the skins set and reduces the risk of rot.
Final Tips For A Perfect Harvest
Harvesting potatoes is simple once you know the signs. Watch the foliage, check the skins, and use a sample dig. Don’t rush, but don’t wait too long either.
If you’re unsure, it’s better to harvest a little early than too late. You can always eat small potatoes right away. But rotten or sprouted potatoes are a total loss.
Store your harvest properly, and you’ll have homegrown potatoes for months. Enjoy the fruits of your labor—literally.
Remember, the exact keyword When Are Potato Plants Ready To Harvest is your guide. Use the foliage die-back as your main signal, and you’ll never dig at the wrong time again.