Few gardening experiences match the pure satisfaction of digging up a bountiful harvest of homegrown potatoes. Digging into the warm soil to find smooth, firm tubers feels like searching for buried treasure. Potatoes are incredibly rewarding to grow, highly productive, and taste vastly superior to anything you can buy at the grocery store.
Whether you have a sprawling backyard garden, raised beds, or just a few grow bags on a sunny patio, you can grow a successful crop of potatoes. By understanding the lifecycle of the potato plant and following a few fundamental steps, you can maximize your yield and enjoy fresh spuds from summer through winter.
Choosing the Right Potato Varieties
Before you plant, you need to choose the right variety for your garden and culinary preferences. Potatoes are generally categorized by how long they take to mature. Selecting the right type helps you plan your planting schedule and manage your garden space efficiently.
First Earlies
First early varieties are the quickest to mature, taking about 10 to 12 weeks. They produce prized new potatoes, which are small, tender, and thin-skinned. Because they are harvested early in the summer, they often escape late-season pests and diseases like potato blight. Popular varieties include Yukon Gold and Red Pontiac.
Second Earlies
These take slightly longer, requiring about 13 to 15 weeks to mature. They produce larger tubers than first earlies but can still be enjoyed as new potatoes or left to grow to full size. They are excellent for boiling, steaming, and salads.
Maincrop Potatoes
Maincrop varieties need the longest growing season, typically taking 15 to 20 weeks to reach maturity. They produce the largest tubers and are the best choices for baking, mashing, roasting, and long-term winter storage. Classic examples include Russet Burbank and Kennebec.
The Importance of Seed Potatoes
To grow healthy potatoes, always start with certified disease-free seed potatoes. Seed potatoes are not actual seeds, but rather small tubers or pieces of tubers used to start the new plant. Avoid planting potatoes purchased from the grocery store. Grocery store potatoes are often treated with growth inhibitors to prevent sprouting, and they may carry viral diseases that can ruin your soil for years.
Before planting, you should prepare your seed potatoes through a process called chitting, or sprouting. Place your seed potatoes in a cool, bright spot out of direct sunlight, such as on a windowsill. Place them with the eyes, or small buds, facing upward. Within two to four weeks, strong, green shoots will begin to grow. Chitting gives your plants a head start once they hit the soil, leading to an earlier harvest.
If your seed potatoes are larger than a chicken egg, you can cut them into smaller pieces before planting. Make sure each piece has at least two healthy eyes. Cut them two days before planting to allow the cut surfaces to dry and form a protective callus. This step prevents the seed piece from rotting in damp soil.
Preparing the Perfect Planting Site
Potatoes are resilient plants, but they thrive when given the right environmental conditions. Select a site that receives at least six to eight hours of direct sunlight daily.
The ideal soil for potatoes is loose, well-draining, and rich in organic matter. Heavy clay soils restrict tuber growth and trap moisture, which leads to rot. If you have clay soil, amend it generously with compost or aged manure, or consider growing your potatoes in raised beds or grow bags.
Potatoes prefer slightly acidic soil with a pH between 5.0 and 6.0. If the soil pH is too high, your potatoes are more likely to develop potato scab, a common cosmetic fungal disease that causes rough, corky patches on the skin.
How to Plant Potatoes: Step-by-Step
Once your soil is prepared and your seed potatoes have sprouted, it is time to plant. Plant your potatoes in the spring, about two to three weeks before your average last frost date. The soil temperature should be at least 45 degrees Fahrenheit.
- Dig trenches: Dig a trench about 6 inches deep and 12 inches wide. If you are planting multiple rows, space the trenches 2 to 3 feet apart.
- Place the seed potatoes: Lay your seed potatoes in the bottom of the trench with the sprouts pointing upward. Space them 12 inches apart for early varieties, and 15 inches apart for maincrop varieties.
- Cover with soil: Fill the trench with about 3 to 4 inches of soil. Do not fill the trench completely yet. Leave the rest of the soil piled along the sides of the trench to use later for hilling.
- Water gently: Water the area thoroughly to settle the soil around the seed potatoes. Keep the soil moist but not soggy.
Caring for Your Potato Plants
As your potato plants grow, they require specific care to produce a heavy yield of healthy tubers. The two most critical aspects of care are watering and hilling.
Hilling Potatoes
Hilling, also known as earthing up, is the most important maintenance task when growing potatoes. Potatoes grow on underground stems called stolons, which emerge above the seed potato. If these growing tubers are exposed to sunlight, they turn green and produce a toxic chemical called solanine, making them inedible.
When the green leafy shoots reach about 6 to 8 inches tall, use a hoe to gently pull soil from the sides of the trench up around the stems of the plants. Cover the lower half of the stems, leaving the top few inches of foliage exposed. Repeat this process every few weeks as the plants grow, eventually creating a mound or hill around each plant. This dark environment encourages more tubers to grow along the buried stems and protects them from sunlight.
Watering and Fertilizing
Potatoes need consistent moisture, especially when they are flowering and forming tubers. Provide about 1 to 2 inches of water per week. Keep the soil evenly moist but never waterlogged. Uneven watering can cause the potatoes to split, hollow out, or develop irregular shapes.
Avoid high-nitrogen fertilizers once the plants are established. Too much nitrogen encourages lush green foliage at the expense of tuber development. Instead, use a balanced fertilizer or one higher in phosphorus and potassium to support strong root and tuber growth.
Managing Common Pests and Diseases
Potatoes can attract several pests and diseases. Regular monitoring and preventive care will keep your crop healthy.
- Colorado Potato Beetle: These yellow-and-black striped beetles and their reddish larvae can quickly defoliate potato plants. Handpick them and drop them into a bucket of soapy water. Look for their bright orange eggs on the undersides of leaves and crush them.
- Potato Scab: To prevent this cosmetic fungal disease, maintain an acidic soil pH and avoid overwatering. Keep the soil moist during the early stages of tuber development.
- Late Blight: This serious fungal disease thrives in wet, warm conditions, causing dark spots on leaves and rotting tubers. Ensure good air circulation, water at the base of the plants rather than from overhead, and plant blight-resistant varieties.
Harvesting and Curing Your Potatoes
The timing of your harvest depends on the type of potato you planted and how you plan to use them.
Harvesting New Potatoes
You can harvest new potatoes shortly after the plants finish flowering, usually in mid-summer. Gently dig around the outer base of the plant with your hands or a hand trowel to harvest a few small potatoes while leaving the rest of the plant to grow. Eat new potatoes immediately, as their thin skins do not store well.
Harvesting Maincrop Potatoes for Storage
For mature potatoes meant for winter storage, wait until the foliage has completely died back and turned brown in the autumn. Once the vines die, leave the tubers in the ground for another 10 to 14 days. This resting period allows the skins of the potatoes to toughen up, which is essential for successful storage.
On a dry day, use a garden fork to gently lift the soil around the plants. Dig well away from the center of the plant to avoid slicing the potatoes. Lift the tubers out of the soil and brush off any loose dirt. Do not wash them, as excess moisture will cause them to rot during storage.
Curing and Storage
To store your potatoes for the winter, you must cure them first. Place the unwashed potatoes in a dark, well-ventilated area with temperatures around 55 to 60 degrees Fahrenheit for two weeks. This curing process heals any minor cuts and further thickens the skins.
After curing, store your potatoes in a cool, dark, humid location with temperatures between 40 and 45 degrees Fahrenheit. A root cellar, basement, or cool garage is ideal. Keep them in breathable containers like burlap bags, cardboard boxes, or paper bags. Never store potatoes in the refrigerator, as the cold temperatures will convert their starches into sugars, ruining their flavor and texture.
Frequently Asked Questions
Can I grow potatoes in containers?
Yes, potatoes grow exceptionally well in containers and grow bags. Choose a container that holds at least 10 to 15 gallons of soil with excellent drainage holes. Plant two to three seed potatoes in the bottom with 4 inches of soil, and add more soil as the plants grow, just like you would hill them in the ground.
Why are my potatoes turning green?
Potatoes turn green when they are exposed to light, either while growing in the ground or after harvest. This green color indicates the presence of chlorophyll and solanine, a toxic compound. Always keep your growing potatoes well-covered with soil or mulch, and store your harvested potatoes in complete darkness.
What plants should I not plant next to potatoes?
Avoid planting potatoes near tomatoes, eggplants, or peppers, as they are all members of the nightshade family and can share the same pests and diseases. Also, keep them away from fennel, pumpkins, and squash, which can stunt potato growth.
Growing your own potatoes is an incredibly satisfying gardening project that yields a versatile, nutritious, and delicious staple crop. By selecting quality seed potatoes, mastering the art of hilling, and giving your plants the water and sunshine they crave, you will enjoy a spectacular harvest of fresh, flavorful potatoes. Once you taste a potato fresh from your own backyard, you will want to make room for them in your garden year after year.