Why Grow Potatoes in Bags? (The Benefits)

Before we get our hands dirty, let’s talk about why this method has become the gold standard for home gardeners. If you’ve tried growing in the ground and struggled with heavy clay soil or pests, you’re going to love this.

• Perfect Drainage: Potatoes hate “wet feet.” In a bag, excess water drains away easily, preventing the dreaded potato rot.
• Controlled Soil Environment: You aren’t at the mercy of your backyard’s soil quality. You get to decide exactly what nutrients your plants are getting.
• Warmth: Fabric bags or dark plastic bags absorb heat faster than the ground, which can give your potatoes a head start in early spring.
• No Digging Required: When it’s time to harvest, you don’t need a pitchfork. You simply tip the bag over and pick up your “gold.”
• Pest Management: It’s much harder for soil-dwelling pests like wireworms to find your crop when it’s elevated in a bag.

Choosing Your Gear: What Bags Should You Use?

You don’t need anything fancy to get started, but choosing the right container makes a difference. Here are the three most popular options:

1. Commercial Fabric Grow Bags

These are specifically designed for gardening. They are made of breathable felt-like material that “air prunes” the roots, preventing them from circling and becoming root-bound. Look for bags with handles and a “harvest window” flap at the bottom—it allows you to sneak a few baby potatoes out without disturbing the whole plant!

2. Heavy-Duty Plastic Bags

If you’re on a budget, you can use heavy-duty trash bags or even the 50lb bags that birdseed or rice comes in. The key here is drainage. You must poke dozens of holes in the bottom and sides to ensure water can escape.

3. Burlap Sacks

Old coffee sacks or potato sacks are classic. They look beautiful and are incredibly breathable. However, they tend to dry out very quickly and can rot by the end of the season. If you use burlap, be prepared to water more frequently.

Selecting the Right Potato Varieties

Not all potatoes are created equal. When growing in bags, you need to understand the three main categories to ensure your timing is right.

First Earlies

These are the “new potatoes.” They grow fast (about 10-12 weeks) and don’t take up much room. Because they are harvested small, they are perfect for bag growing. Try varieties like Rocket or Casablanca.

Second Earlies

These take a bit longer (13-15 weeks). They are still relatively compact and offer a slightly larger yield. Charlotte is a fan favorite here for its waxy texture and amazing flavor.

Maincrops

These are your storage potatoes—the big ones you use for mashing and roasting. They take 15-20 weeks to mature. While you can grow them in bags, they require much larger bags (at least 10-15 gallons) to reach their full potential. King Edward or Russet fall into this category.

The Secret Ingredient: Seed Potatoes

One common mistake beginners make is trying to plant a potato from the grocery store. While those can grow, they are often treated with growth inhibitors to keep them from sprouting on the shelf. They also aren’t certified disease-free.

Always buy certified seed potatoes. These are guaranteed to be free of viruses and blights that could ruin your crop and contaminate your garden. Plus, you’ll have a much wider variety of flavors and colors to choose from!

Step 1: Chitting Your Potatoes (The Head Start)

“Chitting” is just a fancy gardening word for sprouting. It’s not strictly necessary, but it gives your plants a 2-week head start on the season.

1. Place your seed potatoes in an egg carton with the “eyes” (the little dimples) facing up.
2. Keep them in a cool, bright spot (like a windowsill) but out of direct sunlight.
3. In 2-4 weeks, you’ll see green, sturdy shoots growing. Once these are about an inch long, they are ready to plant.

Step 2: Preparing Your Soil Mix

Potatoes are heavy feeders, and they love loose, acidic soil. For bags, don’t just use garden soil—it will compact and suffocate the roots. I recommend a “power mix”:

• 60% High-quality potting soil: This provides the structure and drainage.
• 20% Compost or well-rotted manure: This provides the nitrogen and organic matter.
• 20% Perlite or Vermiculite: This ensures the mix stays light and airy.

Pro Tip: Mix in a handful of organic granular fertilizer (balanced, like a 5-5-5) before you start planting.

Step 3: The Planting Process

This is where the magic happens. We aren’t going to fill the bag to the top right away. Instead, we use a method called “hilling.”

1. The Base Layer: Roll the sides of your bag down so it’s only about 1/3 of its full height. Fill the bottom with about 4-6 inches of your soil mix.
2. Placing the Spuds: Place your seed potatoes on top of the soil with the sprouts facing up.
   • For a 5-gallon bag: 2 potatoes.
   • For a 10-gallon bag: 3-4 potatoes.
   • For a 15-gallon bag: 5-6 potatoes.
3. Covering: Add another 3-4 inches of soil on top of the potatoes. Don’t worry if you bury the sprouts; they’ll find their way up!
4. Watering: Give them a good drink, ensuring the soil is moist but not soggy.

Step 4: The Hilling Technique

As your potato plants grow, you’ll notice green stems and leaves reaching for the sun. When the plants are about 6-8 inches tall, it’s time to “hill up.”

Potatoes actually grow from the stems that are underground. By burying the stem, you encourage the plant to produce more tubers. Simply unroll the bag slightly and add more soil mix until only the top few inches of leaves are showing. Repeat this process every couple of weeks until the bag is full to the top.

Step 5: Daily Care and Maintenance

Now that your potatoes are tucked in, your main job is keeping them happy. This comes down to two main things: Sun and Water.

Sunlight Requirements

Potatoes are sun-worshippers. They need at least 6 to 8 hours of direct sunlight per day. If you’re growing on a balcony, make sure the bags aren’t in a permanent shadow. One of the perks of bags is that you can move them throughout the day if you need to chase the sun!

Watering Wisdom

In a bag, soil dries out much faster than in the ground. During the heat of summer, you might need to water every single day. The “finger test” is your best friend: stick your finger 2 inches into the soil. If it feels dry, it’s time to water.

Crucial Rule: Be consistent. If the soil goes from bone-dry to soaking wet repeatedly, your potatoes might crack or develop “hollow heart.”

Feeding Your Potatoes

Since you’re watering frequently, nutrients can leach out of the bag. Every 2-3 weeks, feed your plants with a liquid organic fertilizer. Look for something slightly lower in nitrogen and higher in potassium (like a tomato feed) once the plants are established. Too much nitrogen will give you beautiful green leaves but tiny potatoes.

Dealing with Pests and Diseases

Even in bags, you might run into some unwanted guests. Here’s how to handle them naturally:

• Colorado Potato Beetles: These are bright orange/yellow beetles with black stripes. The best way to deal with them is “hand-picking.” Just pluck them off and drop them in a bucket of soapy water. Check the underside of leaves for their tiny orange egg clusters.
• Aphids: If you see tiny green or black bugs on the stems, a sharp blast of water from the hose is usually enough to dislodge them.
• Potato Blight: This is a fungus that causes brown spots on leaves and can kill a crop quickly. The best defense is prevention: don’t get water on the leaves (water the soil directly) and ensure there is good airflow between your bags.
• Scab: If your harvested potatoes look like they have “craters,” that’s scab. It’s usually caused by soil that is too alkaline. Adding peat moss or pine needles to your mix can help keep the pH slightly acidic to prevent this.

Step 6: The Harvest – When and How?

This is the moment you’ve been waiting for! But how do you know what’s happening underground?

The “New Potato” Phase

If you want small, thin-skinned “new” potatoes, wait until the plant starts flowering. Once the flowers appear, you can reach into the soil and “frobble”—which is a fancy word for gently feeling around and stealing a few small tubers. The plant will keep growing more!

The Main Harvest

For full-sized potatoes, wait for the plant to tell you it’s done. The foliage will turn yellow and eventually die back completely. This is normal! Once the greens have withered, stop watering and wait about 7-10 days. This allows the skins of the potatoes to toughen up, which helps them store longer.

The Big Reveal

Now for the fun part. Spread out a tarp or use a large wheelbarrow. Tip the bag over and let the soil spill out. Sift through with your hands—it’s like digging for buried treasure! You’ll find potatoes of all sizes tucked throughout the root system.

Step 7: Curing and Storage

Don’t wash your potatoes immediately unless you plan to eat them that day. Water can lead to rot during storage.

1. Brush off the dirt: Gently remove large clumps of soil with your hands.
2. Curing: Lay the potatoes in a single layer in a dark, cool, well-ventilated area for about 5-14 days. This further toughens the skin and heals any small nicks from the harvest.
3. Storage: Store them in a burlap bag or a cardboard box in a cool, dark place (like a pantry or basement). Never store potatoes in the fridge, as the cold turns their starch into sugar, ruining the flavor and texture.
4. Keep them away from onions: Onions release a gas that causes potatoes to sprout and spoil faster. Keep these two kitchen staples in separate cupboards!

Common Mistakes to Avoid

Even experts have bad seasons, but you can avoid these common pitfalls:

• Using the wrong soil: Never use 100% garden soil. It will turn into a brick in a bag.
• Overcrowding: It’s tempting to put 10 potatoes in one bag. Don’t do it! You’ll end up with a hundred marble-sized potatoes instead of a dozen large ones.
• Letting them see the light: If a growing potato pushes through the surface of the soil and sees the sun, it will turn green. Green potatoes contain solanine, which is toxic. Keep them covered with soil!
• Forgetting to water: A single weekend of bone-dry soil in July can stunt your harvest significantly.

Frequently Asked Questions

Can I reuse the soil from my potato bags?

It’s tempting, but I don’t recommend it for potatoes two years in a row. Potatoes are prone to diseases that can linger in the soil. However, that soil is great for growing nitrogen-fixing plants like beans or peas the following year!

What can I grow in the bags during the off-season?

If you live in a mild climate, you can grow garlic or kale in the bags over the winter. If not, just empty them, dry the bags out, and store them for next spring.

How many potatoes will I get per bag?

On average, you can expect about 2 to 4 pounds of potatoes per gallon of soil, depending on the variety and how well you feed them. A 10-gallon bag can easily yield 20+ pounds of spuds!

Conclusion: Your Potato Journey Starts Now

Growing potatoes in bags is one of the most rewarding DIY projects a gardener can take on. It’s simple, it’s clean, and the results are literally delicious. Whether you have a massive estate or a tiny fire escape, you have enough room to grow your own food.

So, go out and grab a few bags, some high-quality soil, and your favorite seed potatoes. By mid-summer, you’ll be dumping out a bag of homegrown gold and wondering why you ever bought potatoes from the store in the first place. Happy gardening!