How to Know When to Harvest Potato Plants

Take a close look at the foliage of your potato plants. As the tubers mature underground, the foliage above ground will start to change. Look for signs like yellowing and wilting leaves, which indicate that the plant is redirecting its energy towards tuber growth. This is a natural process as the plant prepares for dormancy, and it's a clear indication that your potatoes are nearing maturity.
Get your hands dirty and gently feel around the base of the potato plant in the soil. Mature potatoes will have developed beneath the surface, and you can often feel them by gently brushing your fingers against the soil. Look for firm, rounded shapes indicating mature tubers.
Assess the skin set of the potatoes by gently scratching the surface of a few tubers. Mature potatoes will have a thicker, tougher skin that doesn't easily rub off. If the skin feels thin and easily rubs off, the potatoes may need more time to mature.
Watch how the flowers and foliage progress throughout the growing season. As the plants mature, you may notice changes in flower color, size, and quantity. The flowers will wilt and fall off.
The foliage of the potato plant begins to yellow and wilt. This is one of the most obvious signs that the plant is nearing the end of its growing cycle. The once lush green leaves start to lose their vibrancy and become increasingly yellow, indicating that the plant is no longer actively photosynthesizing and is redirecting its energy towards tuber development.
Stems of the potato plant may start to turn brown and become brittle. As the plant begins to die back, the stems lose their flexibility and start to dry out. This is a natural process as the plant prepares for dormancy.

Helpful Tools for Potato harvest

A garden fork is ideal for gently loosening the soil around the base of potato plants without causing damage to the tubers.
Shovel can also be used to dig up potatoes, especially in areas with compacted soil or tough roots.
A hand trowel can be handy for delicate digging around smaller potato plants or in tight spaces.
Use a bucket or basket to collect harvested potatoes.
Wearing gardening gloves can protect your hands from dirt, cuts, and scratches while harvesting potatoes.
If you're harvesting a large crop of potatoes, a wheelbarrow can be useful for transporting them from the garden to your storage area.
Use pruning shears or scissors to trim any excess foliage from the potato plants after harvesting.
If you're harvesting potatoes on a sunny day, protect yourself from sunburn by wearing a wide-brimmed hat and applying sunscreen.
Consider wearing knee pads to cushion and protect your knees.
Some gardeners prefer using a harvesting knife or a sharp garden knife to carefully cut away soil and unearth potatoes without damaging them.

A vintage wire screen with fresh harvested potatoes curing in the shade.

How to Harvest Potatoes

Use a garden fork or shovel to gently unearth the potatoes from below the soil surface, being careful not to damage them.
Handle the potatoes carefully during and after harvesting to prevent bruising or cuts. Damaged potatoes won't store as well, so it's important to treat them gently.
After harvesting, you can trim any excess foliage from the potato plants using pruning shears or scissors. This can make handling and curing the potatoes easier.
Once harvested, lay the potatoes out in a single layer in a cool, dark, and well-ventilated area. Avoid washing the potatoes at this stage, as moisture can encourage rotting. Allow the potatoes to air dry for a few hours to remove excess soil and moisture.
After drying, transfer the potatoes to a warm, humid environment for curing. This can be a shaded spot outdoors or a well-ventilated room indoors. The ideal curing temperature is around 60-75°F (15-24°C) with a relative high humidity of 85-90%. Please note that this is slightly cooler than room temperature.
Leave the potatoes to cure for 1-2 weeks, depending on the size and thickness of the skins. During this time, the skins will toughen, and any minor cuts or bruises will heal, improving the potatoes' storage life.
Throughout the curing process, regularly check the potatoes for signs of rotting or sprouting. Remove any potatoes that show signs of damage to prevent them from spoiling the rest of the harvest.
After curing, store potatoes in a cool, dark, and well-ventilated area, such as a root cellar, basement, or pantry. Keep the potatoes away from sunlight, which can cause them to turn green and produce a bitter taste.

When to Harvest Potatoes (time of day & weather conditions)

The best time to harvest potatoes is during dry weather conditions in early summer, preferably on a sunny day. Harvesting potatoes when the soil is dry makes the process easier and less messy, as wet soil can cling to the potatoes and make them harder to clean. Additionally, harvesting in dry weather helps reduce the risk of soil-borne diseases and rotting.

As for the time of day, it's generally best to harvest potatoes in the morning or late afternoon when temperatures are cooler. This helps minimize stress on both the plants and the gardener, especially during hot summer months. Cooler temperatures also help preserve the quality of the harvested potatoes by reducing the risk of dehydration and spoilage.

Avoid harvesting potatoes during rainy or excessively humid conditions, as this can make the soil muddy and difficult to work with. Wet weather can also increase the likelihood of damaging the potatoes during harvest and lead to post-harvest issues like rotting.

Features of a Freshly Harvested Potato

When you freshly harvest a potato from the ground, it looks and feels quite different from what you might find in a grocery store. Here's what you can expect:

A freshly harvested potato will have a thin layer of soil clinging to its skin. The depending on the potato variety, it will likely have thin skins that are delicate, and easily scratched or scuffed. The skin color can range from creamy white to yellow, red, or even purple.
The skin of a freshly harvested potato is soft and pliable, unlike the thicker, tougher skin of a mature potato that has been stored for some time. You can easily rub off the soil with your fingers, revealing the smooth surface underneath.
The size and shape of freshly harvested potatoes can vary widely, depending on the variety and growing conditions. Some may be small and round, while others may be larger and more oblong or irregular in shape.
When you hold a freshly harvested potato in your hand, it should feel firm and solid. There should be no soft spots or areas of decay. The potato should feel heavy for its size, indicating that it is full of moisture and nutrients.
Freshly harvested potatoes have a clean, earthy smell, reminiscent of the soil they were grown in. It's a pleasant, natural aroma that reflects the freshness of the potato.

Optimal Storage Conditions

Potatoes store best in a cool, dark environment with temperatures between 45-50°F (7-10°C). Cool temperatures help slow down the sprouting process and prevent the potatoes from becoming too soft or sprouting prematurely.
Potatoes prefer high humidity levels of around 85-90%. Humid conditions help prevent the potatoes from drying out and keep them firm and fresh for longer periods. You can maintain humidity levels by storing potatoes in a root cellar, basement, or other cool, dark space with good ventilation.
Exposure to light can cause potatoes to turn green and develop solanine, a toxic compound. To prevent this, store potatoes in a dark environment away from direct sunlight. Use opaque containers or coverings to shield them from light.
Proper air circulation is essential for preventing moisture buildup and maintaining freshness. Avoid storing potatoes in airtight containers or plastic bags, as this can trap moisture and lead to rotting. Instead, use breathable containers like burlap sacks or wooden crates, or store them in well-ventilated storage areas.
Fluctuations in temperature and humidity can accelerate sprouting and spoilage. Aim to keep the storage environment as stable as possible to prolong the shelf life of your potatoes. Avoid storing potatoes near sources of heat, such as appliances or heating vents, and minimize temperature fluctuations by insulating the storage area.
In storage, it's best to eat the potatoes that are most prone to sprouting and spoilage first. Generally, this includes the smaller or damaged potatoes, as well as any varieties known for having shorter storage life. Additionally, potatoes with thinner skins are more susceptible to drying out and should be consumed earlier.

Fresh harvested new potatoes sliced for cooking.

Which Potatoes Should You Eat First?

As a rule of thumb, prioritize eating new potatoes first, as they have a shorter shelf life and are best enjoyed fresh. After that, consume any potatoes that show signs of sprouting or softening. Larger, thicker-skinned potatoes typically have a longer storage life and can be enjoyed later in the season. Rotate your potato supply regularly to ensure that you're using up the older potatoes before they spoil, and store them in a cool, dark, and well-ventilated area to prolong their freshness.

What are New Potatoes?

New potatoes are young potatoes that are harvested before they reach full maturity. These early potatoes are typically harvested early in the growing season, usually around the time when the potato plants start flowering. New potatoes have thin, delicate skins and a moist, tender texture. Baby potatoes are prized for their sweet, nutty flavor and creamy consistency. Unlike mature potatoes, which have thicker skins and a starchier texture, new potatoes are best enjoyed soon after harvest when they are at their freshest. These small potatoes are often boiled or steamed whole and served with butter and fresh herbs as a simple and delicious side dish.

Is Harvesting Potatoes Too Early Bad?

First of all, don't panic! There are plenty of home gardeners (myself included!) who love harvesting late spring red potatoes (new potatoes) that are small and immature. They make great roasted potatoes or as salad potatoes. That being said, depending on the type of potato you are growing, here are a few things you might notice:

The potatoes may not have reached their full size or maturity yet. This can result in smaller tubers with less flavor and texture than fully mature potatoes.
Harvesting potatoes prematurely can reduce your overall yield, as the plants haven't had enough time to produce as many tubers as they would under optimal growing conditions.
Potatoes harvested too early may have a lower starch content and higher moisture content than fully mature potatoes. This can affect their taste and texture, making them less desirable for certain culinary applications like frying or baking.
Young potatoes have thinner skins and are more susceptible to damage during harvesting and storage. They may bruise or scratch more easily, leading to spoilage or rotting.
Immature potatoes have a shorter storage life than fully mature potatoes. They may not store as well or for as long, leading to a shorter window of time for consumption before they start to spoil.

FAQ

How do I know if my potatoes are ready to harvest?

There are several signs to look for to determine if your potatoes are ready for harvest. These include observing the foliage for yellowing and wilting, feeling around the base of the plant for mature tubers, assessing the skin set of the potatoes, and monitoring flowering progression. Once these indicators are present, your potatoes are likely ready to be dug up.

Can I harvest potatoes early if I need them sooner?

While it's possible to harvest potatoes earlier than their full maturity if needed, it's generally best to wait until they are fully mature for optimal flavor and yield. Early harvesting may result in smaller tubers and a lower overall yield. However, if you need to harvest early due to weather conditions or other factors, you can still enjoy your potatoes, though they may not store as well.

How do I store harvested potatoes?

After harvesting, allow the potatoes to cure for a few days in a cool, dark, and well-ventilated area to toughen the skin and improve storage life. Once cured, store the potatoes in a cool, dark place with good air circulation, such as a root cellar, basement, or pantry. Avoid storing potatoes in the refrigerator, as the cold temperatures can convert their starches to sugars and affect their taste and texture.

How long after potatoes flower are they ready to harvest?

Potatoes are typically ready to harvest about 2-3 weeks after they flower. It's a good idea to start checking the readiness of your potatoes around this time by gently digging around the base of the plants to see if the tubers have reached a suitable size for harvesting.

What Questions Do You Have?

Did I cover everything? Comment here or message me on instagram @NinnescahHomestead if you need any clarification! I love connecting with fellow gardeners. I've linked plenty of delicious potato recipes to get you in the mood for growing your own. Be sure to check them out!

- Meg

Tasty Potato Recipes

Garden Guides, Tips & Tutorials

If this growing guide was helpful, I recommend reading my Guide to Growing Tomatoes, Garlic Growing Guide, and How to Plant Potatoes. I know you will find all of these posts very helpful, especially if you are a beginner gardener!