Potato Container Size: Everything You Need to Know

This article may contain affiliate links. We get paid a small commission from your purchases. More Affiliate Policy

Potato growing containers come in various sizes, even grow bags of 100 gallons. But what is the optimal potato container size?

A vegetable growing container must optimize water, oxygen, and nutrient availability. The container size should promote root health and productivity and sometimes provide ballast to prevent the plant from toppling over.

Table of Contents

Introduction To Growing Potatoes in a Potato Plant Container

Potatoes are part of the Solanaceae family, cousin to the tomato, pepper, and eggplant. The foliage of all the members of the family contains Solanine, a bitter chemical intended to defend the plant against herbivores and pests.

Solanine is the sister to chlorophyll, the green pigment in plants, the part responsible for photosynthesis. When growing root or tuber vegetables, it’s essential to keep the roots, or tubers in this case, covered, preventing them from turning green.

When carrots or beet “shoulders” are exposed to the sun, the chlorophyll also affects flavor, but not as adversely (and toxic) as Solanine. When potatoes turn green from sun exposure, they should not be eaten.

The optimal temperature range to grow potatoes is between 60 and 65°F (15.5 – 18°C). Do not plant seed potatoes if soil temperatures are below 45°F/7°C. Higher temperatures also adversely affect potato plant growth, which stops at 80°F/26.7°C.

In addition to cooler temperatures, potatoes like full sun (at least 6 hours daily) and organically rich soil that drains well and is slightly acidic (pH 4.8 to 5.8). 

Why Grow Potatoes in Containers?

Growing potatoes in containers is the cleverest gardening trick yet. It allows plant mobility, improved accessibility, easier harvesting, and better defense against soil-borne diseases and the Colorado potato beetle. 

Potato plants are easy to grow but are susceptible to blight and scab diseases. In this post, I share how you can minimize potato risks and get the most bountiful harvest of your potatoes ever.

I’m not anti-soiled, but I have run a repeated comparative test on growing potatoes in garden soil versus in potting soil in containers, and containers win (by far) every time.

What to Look for in a Container for Growing Potatoes?

The results will be similar whether you choose potato grow bags or grow potatoes in containers (buckets); essentially, you want your potato container to give you the following:

• Enough space
• Good drainage
• A healthy environment (unlike tires)
• Easy of handling
• Some aesthetic appeal

Do Potato Plants Grow Well In Grow Bags?

The most excellent thing about growing your potatoes is that they give you unique varieties. Container potatoes give you another unique opportunity—the ability to define your growing medium and improve management schedules. 

Grow potatoes in containers and see for yourself. The proof is in the pudding. Check out the Simplified Gardening YouTube channel and search for Containers, and you can see hundreds of tips demonstrated on growing potato plants in containers. 

Choosing A Potato Grow Bag

When selecting your potato bag, look for the following

• Some upright support for sturdiness. You don’t want it to collapse with the weight of wet soil.
• Potato bags with handles make handling (pun incidental) easier.
• Potato growth bags come in a range of colors. Remember that the darker ones heat up faster, allowing a longer growing season. However, a lighter shade may work better in a region with hot days. Regular hydration helps manage temperature fluctuations.
• Choose grow bags or containers that have good drainage—this is critical.

What Is The Best Size Grow Bag For Potatoes?

A potato growth bag should be at least 12 inches (30 cm) deep and wide. I use the 7-gallon (30 liters) HDPE plastic buckets from Oakland Gardens in the UK.  

Their pots are heavy-duty, thick-walled, won’t crack or split,t and are great for planting potatoes or vegetables. While not exactly in line to win a beauty contest, they provide me with the robustness I need and have served me for almost seven years.

They have drainage holes at the bottom and bottom lip/sides. Perfect.

Potato grow bags should be anywhere from seven gallons (30 liters) upwards, but I have tried larger pots, and they don’t justify their higher costs. I think a seven-gallon container is an ideal size for growing bags.

How Deep Should I Plant Potatoes In Containers Or Bags?

Potato plants should be covered with four to eight inches of soil, and the seed potatoes should rest on a four- to eight-inch layer of potting soil. Potato plants are considered medium-depth root vegetables with roots between 18 and 24 inches.

Plants with deeper roots can better manage dry periods, unlike lettuce or some of the leafy green brassica plants. Pumpkins have the deepest roots (over 3 feet). 

In containers, it is easier to keep the soil moist yet well drained, so the roots do fine in just 6 inches of soil. Remember that the potatoes are not the roots but merely distended stem tips used to store the fuel for regrowing after dormancy (potatoes are perennials grown annually).

The nice thing about grow bags is that they can be folded over at the top, improving rigidity and giving you access to the soil surface. At the same time, the potato plants are still relatively low in the container, and this is important because it also allows direct sunlight access. 

What is Needed In Growing Potatoes In A Bag?

Like all plants, potatoes need five above-ground and five below-ground needs satisfied.

Above Ground	Below Ground
Light Quantity and Quality	Water
Ambient Temperatures	Oxygen
Carbon Dioxide Levels	Soil Temperatures
Airflow	Nutrients
Humidity Levels	Carbon Content & Biodiversity

Let’s look at the ones that apply to container gardens individually. We can exclude humidity and CO₂ levels..

Sunlight and Ambient Temperatures

Grow potatoes where they will get at least 6 hours of direct sunlight – preferably in the morning and late afternoon. 

Air Circulation and CO₂

Cramped accommodation prevents proper air circulation around plants and increases the risk of fungal infection (blight). Don’t overcrowd your potato container with plants. 

Water and Oxygen

Water and oxygen regulation is a function of healthy potting soil. Don’t use garden soil in grow bags or buckets. 

Soil Temperature

Seed potatoes won’t grow if the soil is below 40°F/4.4°C and will slow and stop growing if soil temperatures go above 75°F/24°C. 

Carbon Content and Plant Nutrients

Carbon content increases the electrical charge in soil (cation exchange capacity) that holds water and nutrients in suspension for root access—the more carbon content, the higher the water retention levels. 

Prepare The Potting Soil And Container

Before buying your seed potatoes, ensure you have quality potting soil available. Check out my article on making a potting mix for growing potatoes in containers.

What’s the Best Soil for Growing Potatoes in Containers?

You first want to look at your soil when growing potatoes. Potatoes prefer slightly acidic soil, with a pH between 5.0 – 6.2. You may want to pick up a pH tester at your local garden center or hardware store.

Adding organic matter to your potato grow bags will go a long way to creating excellent loose soil with good water drainage and retention. To optimize water retention and drainage, you must balance organic matter with inorganic matter.

• Inorganic (inert) materials have a limited cation exchange capacity (CEC), and water exerts little adhesive force on them, plowing right past.
• Organic materials are negatively charged and attract and hold onto cations. There is an adhesion between organic materials and water, so water flows slower.

Plant Root Breathability

A half-and-half mixture of organic and inorganic materials is a good starting point and allows you to add the materials needed. 

Organic material also introduces microorganisms that benefit soil health and potato plant resilience. Compost should not include high-nitrogen chicken manure or wood ash that may contribute to potato scab formation.

Use a lightweight potting mix to plant potatoes, ensuring good drainage and keeping the soil moist but not wet. A typical potting soil would work, but what is familiar? It’s better to make your potting mix and know what’s in it. 

Choosing Seed Potatoes To Grow

If you are growing potatoes for the first time or are trying new potato varieties (you should), you will need to purchase seed potatoes. Several specialized or University Extension farms run trials and produce various potato varieties.

Store-bought potatoes are frequently treated to prevent sprouting, so using them as seeds rarely yields good results. However, if you have a local farmer that doesn’t use maleic hydrazide to extend shelf life (prevent sprouting), you can use their potatoes as seeds. 

While you cut potatoes (see my Maximizing Your Potato Harvest: The Truth About Cutting Seed Potatoes article), small seed potatoes are more likely to produce a more bountiful harvest.

Like tomatoes, potatoes have determinate and indeterminate varieties, often sold as early- and mid-season (determinate) and late-season (indeterminate) varieties.

Determinate potatoes proliferate in one layer, making them more popular in the cooler North. This explains why hilling potato cultivars that are determinate does not affect your yield. 

For gardeners in cooler climates, determinate potato types yield earlier than indeterminate types.

Prepare the Seed Potatoes

If planting is delayed, keep seeds cool @ 38°F (3°C). Bring the seed pieces to room temperature for the final two weeks before planting, and the potato will begin to sprout. If sprouts are longer than one inch, keep seed pieces cool until planting time.

Use chitting to encourage early development.

• In a well-lit area, spread the seed potatoes in a single layer. You can do this inside or outside if it’s warm enough.
• The optimal condition to chit potatoes is 70°F/21°C with heavy humidity. Use old egg boxes to hold the chitted seed potatoes.
• To encourage even sprouting, rotate the chitted potatoes.
• Chitting encourages a more vigorous, prolific potato plant and speeds up the emergence of potatoes.
• Potatoes grown from whole-seed potatoes produce a bountiful harvest

Preparing Seed Potatoes For Planting

Make sure the container is clean, even sterile. Wiping the bucket with EM (effective microbes) is best for making Bokashi.

Mix some potting soil with a bone meal, fish meal, and blood meal blend – enough to cover the container’s bottom 6 inches (15 cm).

Place your seeds about 6 inches (15 cm) apart on the layer of soil.

Cover the seed potato with fresh potting soil, leaving about an inch at the top for straw mulch (without weed seeds).

Water the pot with a mixture of water and fish emulsion until the water drains freely from the bottom.

Keep the soil moist (water only) for the next few weeks until the plant emerges.

Watering is essential (but less critical) until the potatoes in containers start blossoming.

How Many Seed Potatoes Per Grow Bag?

The size of your grow bag will determine how many seed potatoes you’ll need. Seed potatoes should be spaced 12 inches (30 cm) apart for optimal air circulation and plant health.

Seed potatoes can produce multiple stems, so don’t plant more than the gro bag can hold.

Tips For Caring For Potatoes Growing In Bags

Keep potatoes in grow bags well hydrated without creating a soggy situation. A potato growth bag drains faster than buckets, so keep an eye on the soil moisture levels.

Apply organic fertilizer (fish emulsion solution) once a month.

Should I Hill The Potatoes Planted In Pots?

Can potted potatoes grow through 8 inches of potting soil to avoid hooking the plant every three weeks? Yes, they can.

Creating a layered version of hilling in pots is not essential, but you can. If you have the time and inclination, adding enough soil to cover a third of the plant’s total external stem every two to three weeks will encourage potato growth as long as the plant is a late-season variety (indeterminate)

Add a few more inches every three weeks to help the plant optimize its photosynthesis efforts and produce more potatoes. Stop the process once flower buds appear, leaving the plant to mature the initiated tubers.

How to Harvest Potatoes Grow in Containers

Harvesting potatoes grown in containers is much less effort than in-soil grown potatoes. Since you can complete most of the work using only your hands, you don’t need to break your back, digging potatoes up and potentially damaging your precious crop.

Once the fruit starts forming, remove and discard these safely, remembering that they are poisonous. 

You can begin harvesting baby potatoes after fruit formation. Leave tubers in the soil for mature potatoes until 50% of the plant’s foliage has died.

You start harvesting more mature potatoes once more than half of the plant has died or leave them in the ground until the whole plant is dead for a maximum harvest. 

Harvest new potatoes by removing all the foliage, soil surface debris and mulch. Tip the bucket or potatoes in a bag over and use your hands to work through the soil to find your treasure trove.

Reuse the potting soil for growing plants unrelated to the nightshade family. Do not use the same potting mix for growing tomatoes, peppers, eggplants or potatoes ever again.

Alternatively, include the used potting mix in your next batch of quality compost.

Enjoy your homegrown, fresh-dug potatoes.

FAQs on Potato Container Size: Everything You Need to Know

In Summary

For earlier crops, choose indeterminate seed potatoes. These need not be hilled as they don’t grow more stems underground. Plant potatoes in early spring for the best outcomes. For those fortunate enough to have cool summers, you can grow potatoes throughout the warmer season as long as temperatures are between 45°F/7°C and 75°F/23°C.

If you found our gardening article informative and enjoyable, why not sign up for our blog updates? Our blog covers various gardening topics, including vegetable and ornamental gardening, lawn care, and indoor plants.

By subscribing, you’ll receive regular updates with our gardening experts’ latest tips, tricks, and advice. Whether you’re a beginner or an experienced gardener, our blog is a valuable resource that can help you take your gardening skills to the next level. Join our community today and start receiving our informative and engaging content straight to your inbox. Just complete the form below.