potato plants

When To Plant Potatoes In Zone 4

Growing potatoes in zone 4 is a great way to add fresh potatoes to your diet. The ideal time to plant potatoes in zone 4 is in the spring, when the soil has warmed to at least 45 degrees F. Zone 4 has a fairly short growing zone, so picking the right variety of potatoes and knowing exactly when to plant is key to getting the most out of your crop.

USDA Hardiness Zone 4 Climate

Climate in growing zone 4 is generally cool, with cold winters and mild summers. The average temperature in this zone falls between -30° to 30°F. First frost typically occurs in late September around the 21st, and the last frost typically occurs near May 12th. Summers are generally warm but not hot, with temperatures rarely reaching above 80°F. Precipitation in this zone is generally evenly spread throughout the year, with snowfall in winter.

The Best Seed Potatoes For Zone 4

When selecting seed potatoes for growing in zone 4, it is important to be mindful of the variety’s days to harvest and the length of time you have before you want to harvest them. 

Early-season varieties such as ‘Yukon Gold’ and ‘Red Norland’ have fewer days to harvest and should be planted as soon as possible for harvesting in late summer. 

Mid-season varieties such as ‘Russet Burbank’ and ‘Kennebec’ have more days to harvest and should be planted in late April or early May for harvesting in fall. 

Late-season varieties such as ‘Cara Russet’ and ‘All Blue’ have the most days to harvest and should be planted in late April or early May for harvesting in early winter. Be sure to select varieties with the right number of days to harvest for your intended harvest date. Some good potato varieties for zone 4 include:

  1. Russet Potatoes: 85-95 days
  2. Yukon Gold Potatoes: 90-110 days
  3. Red Potatoes: 80-90 days
  4. Purple Potatoes: 90-110 days
  5. Fingerling Potatoes: 90-120 days
  6. Sweet Potatoes: 90-120 days
  7. White Potatoes: 90-100 days
  8. All-Blue Potatoes: 95-105 days
  9. Yellow Finn Potatoes: 85-95 days
  10. Kennebec Potatoes: 85-95 days

When To Plant Potatoes In Zone 4

In zone 4, potatoes should be planted 2 weeks before the final frost date. This would typically occur in late April or early May, usually around May 12th, depending on the specific location. Potatoes prefer cooler temperatures and will not do well in hot weather, so it is important to plant them early enough to give them time to grow and mature before the summer heat.

How To Plant Potatoes In Zone 4

To plant seed potatoes, begin by preparing the soil for planting. This can be done by tilling the soil to a depth of approximately 8 inches and adding organic compost to the soil. Once the soil is ready, place the seed potatoes in a sunny location that receives at least 8 hours of direct sunlight. 

The seed potatoes should be planted with the “eyes” facing up and should be spaced approximately 8 to 10 inches apart. Cover the seed potatoes with 3-4 inches of soil, and water them well. Once the potatoes begin to sprout, add more soil to the rows to ensure that the potatoes are well covered. 

Water the potatoes regularly and keep the area free of weeds. 

Caring For Potato Plants

Caring for potato plants is pretty easy – they’re incredibly hardy and generally no-fuss. Potato plants need full sun and well-drained soil to thrive. They should be watered deeply and regularly, allowing the soil to dry out between waterings. 

Fertilizing is also important for optimal growth. Potato plants need a balanced fertilizer with equal parts nitrogen, phosphorus, and potassium. This should be applied every four to six weeks, depending on the soil’s nutrient content. 

It is also important to keep the soil evenly moist, as potatoes do not tolerate dry or waterlogged conditions. Mulching around the potato plants can help retain moisture and reduce weeds.

When To Harvest Potatoes In Zone 4

There are two sure ways to know your potatoes are about ready to harvest! The first is counting backward from your current date to their planting date. Potato varieties have an approximate number of days to harvest, so consult the days to harvest for the particular variety of potatoes you’ve planted. If you aren’t sure, assume it’s around 100 days.

The appearance of your potato plants is another dead giveaway. You will know your potatoes are ready to harvest when the foliage begins to turn yellow and die back. Allow the soil around the plants to dry before harvesting, but don’t allow it to be dry for too long. Once harvested, inspect the potatoes carefully- they should be firm and free of green or soft spots.

Thomas Nelson
Gardening Expert
Hi! I'm Thomas, one of the founders of The Garden Magazine. I come from a long line of gardeners who used the art of gardening as a way to live long, healthy lives. I'm here to share my knowledge of gardening with the world!