When a potato plant has fully grown foliage, how do you know if it's time to harvest the potatoes?
Generally, it is best to wait until the foliage dies back, before harvesting maincrop potatoes.
Another way is to try digging around the plant to see if there are any potatoes that are ready to be harvested.
It's important to note that planting and harvest times may vary depending on your location and climate. Be sure to take a look at my guide to growing zones.
When it comes to determining the best time to harvest potatoes, there are a few factors to consider.
The first is the type of potato you're growing. Early potatoes, which are typically ready in about 75 to 90 days, can be harvested when the plants start to flower.
Whereas, Maincrop potatoes take longer to mature, are typically harvested once the foliage has died back.
A further factor to consider is the weather. As wet soil can cause potatoes to rot, it is usually best to wait until the soil is dry before harvesting.
It's also important to avoid harvesting potatoes when the weather is too hot, as this may cause their skins to crack, and the potatoes to spoil much more quickly.
As mentioned, above, one way to determine if your potatoes are ready to harvest is to dig around the plant, and see if there are any potatoes that have reached a desirable size.
If the potatoes are still small, it's best to wait a bit longer before harvesting. Be sure to be careful when digging around the potato plants to avoid bruising or damaging them.
Types of Potatoes
With the above in mind, let's take a look at some of the most common potato types used by gardeners, along with their pros and cons, ideal planting time, and time to harvest:
Russet Potatoes
Pros: High starch content makes them ideal for baking and frying. They are particularly good for making mashed potatoes.
Cons: Unfortunately, they are less flavorful than other varieties. Susceptible to bruising and browning.
Ideal planting time: Early spring, when the soil temperatures are above 45°F (7°C).
Time to harvest: 80 to 100 days after planting.
Planting depth: 4 to 6 inches (10 to 15 cm).
Yukon Gold Potatoes
Pros: Creamy texture and rich flavor. Good potatoes for boiling, roasting, and mashing. Can be expensive to buy, so a great plant to grow money-wise. Plants are resistant to scab.
Cons: These produce lower yields than some other varieties.
Ideal planting time: Early to mid-spring, when soil temperatures are above 45°F (7°C).
Time to harvest: 70 to 90 days after planting.
Planting depth: 4 to 6 inches (10 to 15 cm).
Fingerling Potatoes
Pros: These have a somewhat nutty, buttery flavor. Good for roasting and salads. Their small size makes them easy to cook and serve. Good to grow as they are quite expensive to buy.
Cons: These typically produce lower yields than other varieties.
Ideal planting time: Early spring, when soil temperatures are above 45°F.
Time to harvest: 70-100 days after planting.
Red Potatoes
Pros: Tender and moist, with a slightly sweet flavor. Great for roasting, boiling, and using in potato salads.
Cons: Their thin skins can make them susceptible to damage. Unfortunately, they can be prone to scab.
Ideal planting time: Late winter to early spring, when soil temperatures are above 45°F (7°C).
Time to harvest: 70 to 100 days after planting.
Planting depth: 4 to 6 inches (10 to 15 cm).
Purple Potatoes
Pros: These have high levels of antioxidants, and their vibrant color makes them visually appealing. Good for roasting and salads.
Cons: Lower yields than some other varieties.
Ideal planting time: Early spring, when soil temperatures are above 45°F (7°C).
Time to harvest: 70 to 100 days after planting.
White Potatoes
Pros: Mild, delicate flavor. Good for boiling and mashing.
Cons: Often less flavorful than other varieties. May be susceptible to scab.
Ideal planting time: Late winter to early spring, when soil temperatures are above 45°F (7°C).
Time to harvest: 70 to 100 days after planting.
In summary, the best time to harvest potatoes depends on the type of potato you're growing, the weather conditions, and the size of the potatoes.
Early potatoes can be harvested when plants start to flower, while maincrop potatoes should be harvested once the foliage has died back.
It's important to wait until the soil is dry and avoid harvesting in hot weather, and to handle the potatoes carefully to avoid damage.
Sources used
References used for 'when is it best to harvest potatoes' and the 'information on the most common types of potatoes grown by gardeners'.
"When to harvest potatoes" by the RHS: https://www.rhs.org.uk/advice/grow-your-own/vegetables/potatoes#when-to-harvest-potatoes
"How to Harvest Potatoes" by Almanac: https://www.almanac.com/pest/potato-harvest
"How to Harvest and Store Potatoes" by GrowVeg: https://www.growveg.com.au/guides/planting-tips-for-a-better-potato-harvest/
Old Farmer's Almanac. (n.d.). Potatoes. https://www.almanac.com/plant/potatoes
University of Maine Cooperative Extension. Growing Potatoes in the Home Garden: https://extension.umaine.edu/publications/2410e/
You may also be interested in reading some of my in-depth vegetable growing guides: How to grow tomatoes, growing cucumbers, and How to Grow Parsnip in Your Vegetable Garden.
