How Much Soil Do I Need For a 5 Gallon Pot

Container gardening is the perfect solution for when you aren’t able to plant in the ground. Pots allow you to grow food and flowers on your front porch or balcony without the need for a backyard.

5 gallon pots are a popular choice for gardeners because they hold enough soil to allow plants to grow nice and big. But exactly how much soil is appropriate for a 5 gallon pot?

On average, a 5 gallon pot can fit about 20 quarts of soil. Your typical bag of store-bought potting soil is 16 quarts. So, it takes about 1 ¼ bags of potting soil to fill a 5 gallon pot.

How Many Gallons Are in a Bag of Soil?

Bags of soil
It can be confusing to figure out exactly how much soil to buy because different brands measure their soil differently. The most common measurements are cubic feet (cu ft) or quarts (qt).

Pots and containers unfortunately use totally different units of measurement. If you’re buying a pot, their sizes will usually be written in either inches (“) or gallons (gal).

The most common and readily available sized bag of soil is 16 quarts. These are the bags of soil that you can pick up at the hardware store and are sold by brands like Miracle-Gro. Of course, there are much bigger sized bags but 16 quartz is a good standard to refer to.

How Do I Calculate How Much Soil I Need?

If you’re stuck in the gardening aisle and feel a wave of mathematical confusion, don’t panic! Thankfully, there are formulas to help you figure out the right amount of soil for your 5 gallon pot.

If you’re buying potting soil measured in quarts (which is most common), use this conversion:

  • 1 quart = 0.25 gallons

Cubic feet is a larger measurement than quarts, so it’s usually reserved for big bags of soil. If your soil is measured in cubic feet, use this conversion:

  • 1 cubic foot = 7.48 gallons

How Much Soil to Put in a 5 Gallon Pot?

Using the above conversions, let’s calculate the number of gallons in your typical bag of soil. A standard sized bag of potting soil is 16 quarts, so:

  • 16 quarts x 0.25 = 4 gallons

So you’ll need a bit more than a single 16 quart bag to fill your 5 gallon pot. About 1 ¼ bags of soil should do the trick!

How Much Space Should I Leave?

Hands putting soil in a pot
When you’re filling up your 5 gallon pot, is it better to leave space or fill to the top? Potting soil is filled with air and is designed to absorb water. So you have to take into account that the soil will compress over time.

In general, you should fill a big container like a 5 gallon pot almost to the top. You can leave about a 2 inch space between the soil and the top of the pot (also called the “head space”). If the space is larger than this, your plants will sit too low and risk not getting enough sun.

If you don’t add enough soil, your plants may not develop a deep enough root system. This can stunt your plant’s growth and even cause you to accidentally overwater. So, although it can be pricey to fill up the whole 5 gallon pot, your plants will thank you for it!

Should You Add Drainage Material to 5 Gallon Pots?

Whether or not you should add drainage material all depends on your pot. Most commercially available 5 gallon pots will have drainage holes drilled in the bottom. This allows excess water to escape out of the bottom and prevents your roots from sitting in water. This is important because roots that sit in water will start to rot and cause your plant to die.

If your pot doesn’t have drainage holes, you can drill some yourself. In general, avoid buying a 5 gallon pot if it doesn’t come with drainage.

But if your pot doesn’t have holes, the best solution to avoid soggy soil is to add drainage material. Good drainage materials include pine bark strips or bark nuggets. These materials allow water to pass through, and they absorb excess water from the soil. Avoid using rocks or pebbles, as water tends to sit on top of them rather than drain.

Can You Grow Vegetables in 5 Gallon Buckets?

5 gallon buckets are readily available at most hardware and garden stores. They’re incredibly useful for all sorts of things around the house, including gardening! They can be used in place of a 5 gallon pot for a fraction of the price.

Vegetables will grow wonderfully in a 5 gallon bucket, with a few modifications. These buckets don’t come with drainage so you’ll have to drill holes in the bottom. About 6-8 holes will do but you can add more if you need.

Vegetables that grow well in 5 gallon buckets are those with far-reaching root systems. These include:

  • Tomatoes
  • Bell peppers
  • Lettuce
  • Zucchini
  • Eggplant

Tip: White buckets are the best option since they will not absorb as much sunlight and dry out the soil. Black buckets can be used in colder months like autumn when your vegetables need to absorb warmth.

How Many Plants Fit in a 5 Gallon Pot?

Vegetable plant
Although 5 gallon pots can hold a decent amount of soil, how many plants can actually fit inside? It depends on the type of plants you are growing. You can generally fit about 6-8 types of flowers in a 5 gallon pot. This leaves enough room for them to grow without the pot getting too crowded.

If you’re planting fruits and vegetables, the number is more limited. Plants like tomatoes, squash, eggplant, and broccoli require more room to grow. They should only have 1 plant per 5 gallon pot.

Plants such as leeks, peas, potatoes, and radishes grow better in tight quarters. You can have multiples of these plants in one 5 gallon container.

Tips for Planting in 5 Gallon Pots

Water Often

Potted plants require more water than plants in the ground. This is because their roots cannot reach further into the ground to get more water. In the summer, your potted plants will require daily watering.

Sterilize Your Pots First

Sterilize your pot before adding soil or plants. Pots from the store may have chemicals on them that can harm your plants. If you’re reusing old pots, you should clean them to make sure there’s no bacteria or plant fungus. Plain soap and water or a plant-friendly all-purpose cleaner will work fine, just rinse well!

Choose Good Quality Material

Choose a good quality material for your pot. Plastic is light and cheap but tends to crack very easily. Clay or terracotta pots are inexpensive and look nice but dry out the soil. Whichever material you choose, make sure it has drainage holes on the bottom or can be drilled into.

Start with Seedlings

Start the seeds in a smaller container and transport seedlings once they’re more mature. Starting with seedlings lets you begin the growing process earlier in the season.

If you live in a colder climate, starting seedlings indoors will prevent them from dying from frost. Small seedling containers are much easier to manage indoors than a giant 5 gallon pot.

You can always buy seedlings at the nursery in the spring but the quality can be iffy. If you start your plants at home, you know exactly the conditions they’ve been through.

Bring Them in From the Cold

In the wintertime, you can bring the pots inside to keep your plants from dying. Some plants go dormant over the winter, while others will continue to produce as long as they have enough light. Many herbs and annual plants will continue to grow during the winter indoors!


Container gardening allows you to grow fruit, vegetables, and flowers no matter where you live. 5 gallon pots are especially favored for vegetable gardening, but they require quite a bit more soil than your typical houseplant pot. By knowing exactly how much soil you need, you can be sure to buy the correct amount.

An average 5 gallon pot can hold about 20 quarts of soil. Meanwhile, the average bag of store-bought potting soil is 16 quarts. So, it takes about 1 ¼ bags of potting soil to fill a 5 gallon pot.

Now that you know how much soil you need, you can get started on your very own potted garden!