Growing potatoes in Wisconsin is a great way to enjoy fresh, homegrown potatoes. The state’s rich, sandy soil and moderate climate make it the perfect place for growing potatoes. Potatoes can be planted as early as late April, when the soil warms up, and harvested from late July through October.
Fertilizing and mulching are important for healthy and productive plants. Potatoes also need plenty of water, so it’s important to keep the soil moist throughout the growing season. With a little care and attention, Wisconsin gardeners can enjoy a bounty of delicious potatoes.
Wisconsin’s Hardiness Zones And Climate
Wisconsin has four different growing zones which range from zone 3 to zone 5. Zones 3 to 5 are generally characterized as having cold winters with moderate summers. In zone 3, temperatures can dip as low as -40 degrees Fahrenheit, while in zone 5 temperatures typically range between -10 and 30 degrees Fahrenheit.
The growing season in zones 3 and 4 ranges from late May to early October, while in zone 5 it can range from late April to late October. Precipitation also varies by zone. Rainfall totals in zones 3 and 4 range from 25 to 30 inches annually, while in zone 5 they range from 28 to 32 inches.
Snowfall totals can also vary by zone. Zones 3 and 4 receive around 40 inches of snowfall each winter, while zone 5 can get up to 50 inches. Overall, Wisconsin’s growing zones 3 to 5 are best suited for cold-weather crops such as root vegetables, brassicas, and leafy greens. With well-draining soil, plenty of moisture, and the right amount of sunshine, these zones are ideal for growing a variety of fruits, vegetables, and other plants.
Different varieties of seed potatoes
When selecting seed potatoes for growing in Wisconsin, 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 Wisconsin include:
- Russet Potatoes: 85-95 days
- Yukon Gold Potatoes: 90-110 days
- Red Potatoes: 80-90 days
- Purple Potatoes: 90-110 days
- Fingerling Potatoes: 90-120 days
- Sweet Potatoes: 90-120 days
- White Potatoes: 90-100 days
- All-Blue Potatoes: 95-105 days
- Yellow Finn Potatoes: 85-95 days
- Kennebec Potatoes: 85-95 days
When To Plant Potatoes In Wisconsin
In Wisconsin, potatoes should be planted in the spring after the last frost date. Planting should begin in early April and continue until early June. Potatoes should be planted in soil that is at least 45°F. To ensure a successful harvest, it is important to make sure the soil is deeply tilled, fertilized, well-drained, and free of weeds. The planting dates for potatoes are:
- Zone 3: Around May 1st
- Zone 4: Around April 30th
- Zone 5: Around April 15th
How To Plant Potatoes In Wisconsin
Begin the planting process for seed potatoes by tilling the soil to a depth of 8 inches and incorporating organic compost. Once you have done this, find a sunny location that receives at least 8 hours of direct sunlight and place the seed potatoes.
Plant the seed potatoes with the “eyes” facing upward, leaving a distance of 8 to 10 inches in between each. Cover the seed potatoes with a layer of soil that is 3-4 inches thick, and make sure to water them adequately. As the potatoes start to sprout, add more soil to the rows to keep them adequately buried.
Water the potatoes on a regular basis and remove any weeds from the area. For those living in hot and dry climates, you may want to cover the soil around the potatoes with straw, although this is not essential.
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 Wisconsin
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. Your plants will go through an entire flowering cycle, which is nice because the flowers are really beautiful.
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.
Carefully dig up the potatoes with a garden fork, taking care not to damage the potatoes in the process. Once the potatoes have all been dug up, brush off any excess soil and inspect them for any damage. Discard any potatoes that are damaged, as these are not suitable for long-term storage.
Finally, gently place the potatoes in a cool, dry, and dark area for storage. It is important to only store undamaged potatoes, as damaged potatoes can quickly rot.
