How Much Soil Do Raised Garden Beds Need (2024)

When it comes to gardening, raised beds have become increasingly popular due to their benefits such as better drainage, improved soil quality and easy maintenance. However, the question arises: how much soil volume do you need for a raised bed?

In this article, we will explore the answer to this question and show you how to calculate the amount of soil needed for raised beds. We will also look at the best soil for a raised bed garden to help plants grow. By looking at these two topics, we hope to equip you with all the necessary information to make your raised-bed gardening experience a success.

What is a Raised Bed and Why is it Useful for Gardening?

How Much Soil Do Raised Garden Beds Need (1)

A raised bed, sometimes referred to as a garden bed or a planting bed, is a garden technique that involves creating a garden area - one that is typically rectangular or square-shaped - that is raised above ground level. A raised bed is usually framed with wood, stone, concrete blocks or other materials and filled with soil for planting. The height of a raised bed can vary and can be customized to the gardener's preference.

There are several advantages to using a raised bed for gardening. Because a raised bed is above ground level, it allows for better drainage, prevents soil compaction and improves air circulation. Raised beds are also easier to maintain, and they provide better control over the soil quality. They also offer better accessibility and make it easier to manage a garden.

If you're starting a raised garden bed buildup, you will need the following materials: wood boards, corner brackets, screws, drill, soil, compost and topsoil. Other materials that can be used include concrete blocks, stones, bricks or cinder blocks. Before building your raised bed, consider the dimensions and location of your garden bed and ensure the materials you use are suitable for the location.

How Much Soil Do Raised Garden Beds Need (2)

How Much Soil Do I Need for My Raised Bed?

Many gardeners have never even considered the possibility that a garden can have too much or not enough soil - but it can. Having too much soil causes excessive water retention that can lead to root rot, and it can lead to the plant "spilling" out of the bed. On the other hand, not enough soil means the plants are harder to see, and it becomes more difficult to grow plants with larger root systems.

There are several ways we can approach the soil calculations you'll need for a raised bed garden. Here are some of the most common methods.

Using a Soil Calculator

Using a soil calculator is a quick and easy way to determine the amount of soil you need for your raised bed. Simply input the dimensions of your raised garden bed along with the desired depth of soil and the soil calculator will automatically tell you how much soil you need.

Here at Frame It All, we have a Soil Calculations page with a chart that gives you the recommended soil amount (in cubic feet) for all our raised bed designs. If you have a garden bed size or design that is not listed, consider the method below to calculate the soil needed for your raised beds.

Using the Area Method

Another way to calculate how much soil you need is by using the area method. Simply multiply the length and width of your bed together, then divide that number by 27 (the cubic feet in a cubic yard). This will give you the number of cubic yards of soil you need, assuming an average soil depth of one foot.

For example, if your raised bed is five feet long by four feet wide (20 square feet), you will need approximately 0.74 cubic yards of soil. If your length and/or width measurements are in inches, remember to divide them by 12 to convert to feet before doing the calculation.

Factors That Affect Soil Volume in Raised Beds

When calculating the amount of soil you need for your raised bed, several factors come into play such as the size of the bed, the vegetable garden bed depth, the type of plants you want to grow, and the type of soil you want to use. Some plants require more soil depth than others, and soil volume can also be affected by the type of soil you use.

If you're not sure how deep a raised garden bed should be, the rule of thumb is 8-12 inches for most vegetables. However, if you plan to grow root crops such as carrots or beets, 12-18 inches is recommended. You may also need additional soil depth if you're using a Lasagna garden bed method or a deep mulch gardening approach.

How Much Soil Do Raised Garden Beds Need (3)

What Type of Soil is Best for Raised Beds?

Recommended Soil Mix for Growing Vegetables and Flowers in Raised Beds

The best soil mix for raised beds is one that is rich in organic matter, drains well and is nutrient-dense. A good soil mix can be made using a combination of one-third compost, one-third topsoil and one-third potting soil. This mixture provides a suitable environment for plants to grow while also retaining moisture and providing nutrients, which will allow you to enjoy the benefits of a raised garden bed to the fullest.

If you cannot make a soil mix, you can purchase a pre-made organic soil mix specifically designed for raised beds. For best results, it's important to choose an all-natural, organic potting soil that is free of synthetic fertilizers and pesticides. A good garden soil mix should also include perlite, vermiculite and other materials to promote drainage and aeration.

Additionally, you can add slow-release fertilizers, compost tea and a mulch layer to your raised bed soil mix to ensure that your garden is adequately nourished.

Using Compost and Topsoil in Your Raised Bed

Compost is a great addition to a raised bed garden as it provides organic matter which is essential for plant growth. Topsoil, on the other hand, is the top layer of soil that is rich in nutrients and minerals and is also important for plant growth. Using a combination of compost and topsoil is an effective way to ensure your raised bed has the necessary nutrients for your plants to thrive.

Pros and Cons of Using Peat-based Soil Mixes in Raised Beds

Peat-based soil mixes are commonly used in raised beds as they help retain moisture, provide good drainage and are pathogen-free. However, these mixes can be expensive and may not be environmentally friendly. Peat is a non-renewable resource, and its harvesting can have negative effects on the environment. It is also on the acidic side, which some plants won't respond well to. Therefore, it is essential to consider the pros and cons of peat-based soil mixes before using them in your raised bed garden.

How to Fill a Raised Bed with Soil?

How Much Soil Do Raised Garden Beds Need (4)

Buying Soil in Bags or Bulk: Pros and Cons

When it comes to buying soil for your raised bed, you can either buy it in bags or in bulk. Buying soil in bags is convenient as it does not require any measuring or calculations. However, it can be expensive and time-consuming. Buying soil in bulk, on the other hand, is cost-effective but requires some effort as you will need to transport the soil to your garden.

In any case, the way you buy your soil for raised beds will depend on your budget, the availability of soil in bulk and personal preference.

Soil Mixes for Raised Beds

Many soil mixes are available for different types of plants. Before purchasing any soil mixes for your raised bed, it is important to do research and find out which type of soil mix would be most suitable for your garden.

Calculating the Amount of Soil You Need for Your Raised Bed

Calculating the amount of soil you need for your raised bed is an important step as it helps to ensure that you do not run short of soil or end up with too much soil. Once you have determined the cubic feet of soil required, you can calculate the number of bags or cubic yards of soil you need for your raised bed.

How Much Soil Volume is Necessary for a Specific Raised Bed Size?

The amount of soil needed for a specific raised bed size varies depending on the dimensions of the garden bed and the desired soil depth. As a rule of thumb, a 4' x 8' raised bed that is six inches deep requires approximately eight bags of soil while a 4' x 8' raised bed that is 12 inches deep requires approximately 16 bags of soil.

Buy Your Garden Bed Equipment From Frame It All

How Much Soil Do Raised Garden Beds Need (5)

Bored with the same old garden, but can't find a way to make a change? Frame it All has the perfect solution: create your own customized raised garden bed setup. Not only do you have a large selection of sizes and styles to choose from, but our patented interlocking panels also provide optimal drainage and increased aeration for healthier soil. Plus, because of its elevated design and included protective cover, your raised beds are protected from unwanted pests that might otherwise wreak havoc on your flowers or veggies.

With Frame It All's raised bed system, you not only get protection and convenience but also complete control over how the bed is configured. Get creative by adding trellises or separators and dividers, add extra height or utilize corner pieces to form inspiring shapes. The possibilities are endless, allowing you to tailor-make your dream outdoor living space without hiring an expensive contractor.

Start building the perfect garden now with Frame It All's one-of-a-kind raised bed systems available for purchase online today!

How Much Soil Do Raised Garden Beds Need (2024)

FAQs

How Much Soil Do Raised Garden Beds Need? ›

For example, if your raised bed is five feet long by four feet wide (20 square feet), you will need approximately 0.74 cubic yards of soil. If your length and/or width measurements are in inches, remember to divide them by 12 to convert to feet before doing the calculation.

How many bags of soil do I need to fill a 4x8 raised bed? ›

If you're planning a 12-inch deep raised bed, you'll need approximately 24 cubic feet of soil to fill a 4x8 bed. A depth of 18 inches will require approximately 36 cubic feet of soil. The type of soil you use will also affect the volume required to fill your raised bed.

How deep should soil be for raised beds? ›

A raised bed does not need to be very deep to be effective, but the surface underneath your garden bed affects which depth is right. In general, eight inches is a good minimum depth for raised garden beds.

How deep should raised beds be for tomatoes? ›

Tomatoes should ideally be grown in a raised bed that's at least 15 to 18 inches deep. Many of my clients in Houston are successfully growing tomatoes in 12-inch deep raised garden beds, but their plants tend to be a little stunted compared to plants in deeper beds.

Should I put rocks in the bottom of my raised garden bed? ›

Rocks can cause uneven water distribution within the bed, leading to variations in moisture levels among plants. This inconsistency can negatively impact plant health and growth. Perched water table. Contrary to popular belief, rocks do not significantly enhance drainage when put at the bottom of a raised garden bed.

Is it OK to use potting soil for raised beds? ›

While potting mix alone is too light for use in raised beds, creating a 50:50 blend of potting mix and Miracle-Gro® All Purpose Garden Soil will give just the right balance. Top-notch potting mix and raised bed soil may cost more than low-quality versions, but you really get what you pay for.

Do you put topsoil in raised beds? ›

Filling Raised Beds

We fill our beds with half compost and half topsoil. It's economical, the soil gives the plants' roots something to hold onto, and the compost feeds the plants.

How do you fill a raised garden bed cheap? ›

Fill the bottom half with broken branches, twigs and general forest waste. Add green material like grass clippings, weeds (without roots or seeds) comfrey cuttings, kitchen vegetable waste. Top up with 6 inches of topsoil and home-made compost mix.

What is best to fill a raised bed? ›

The first option for filling your beds is a simple soil mixture. As you may have guessed, this is the simplest route you can take. Fill your bed with a 1:1 mixture of topsoil and compost mix, then lightly combine with a rake or shovel.

Which vegetables need deep soil? ›

Pumpkins, winter squash, and watermelons have deep roots that go down 24 to 36 inches or more. Tomatoes, artichokes, okra, and sweet potatoes also have deep roots.

How many tomato plants can I plant in a 4x4 raised bed? ›

A 4ft. x 4ft. raised garden bed gives you 16 square feet of growing space (more if you add some trellises for vertical space). That means you can grow around 10 to 11 indeterminate, or vining, tomato plants in one raised bed—if you really love cherry tomatoes, that is.

Is 10 inches deep enough for raised bed? ›

However, the bottom must be strong enough to both hold the weight of the soil when it is wet and still allow water to drain. A few other considerations to keep in mind: Most garden crops need at least 10 inches of soil to thrive. If the raised bed height is lower than this, till the existing soil below the raised bed.

How many yards of soil for 8x4 raised bed? ›

Each 4'x8' bed will require 1 cubic yards of soil.

How much topsoil do I need to fill a raised bed? ›

Simply multiply the length and width of your bed together, then divide that number by 27 (the cubic feet in a cubic yard). This will give you the number of cubic yards of soil you need, assuming an average soil depth of one foot.

How many bags of soil do I need for a raised bed? ›

For example, if you want to make your raised bed 12 inches deep, you'll need approximately 1.5 cubic feet of soil per square foot. This means that you'll need approximately 12 cubic feet of soil for an 8 square foot, 12-inch-deep raised bed. In this case, you'll need 12 bags of garden soil.

How do I calculate how many bags of soil I need? ›

Length in feet x Width in feet x Depth in feet (inches divided by 12). Take the total and divide by 27 (the amount of cubic feet in a yard). The final figure will be the estimated amount of cubic yards required.

Top Articles
Latest Posts
Article information

Author: Aron Pacocha

Last Updated:

Views: 5914

Rating: 4.8 / 5 (48 voted)

Reviews: 95% of readers found this page helpful

Author information

Name: Aron Pacocha

Birthday: 1999-08-12

Address: 3808 Moen Corner, Gorczanyport, FL 67364-2074

Phone: +393457723392

Job: Retail Consultant

Hobby: Jewelry making, Cooking, Gaming, Reading, Juggling, Cabaret, Origami

Introduction: My name is Aron Pacocha, I am a happy, tasty, innocent, proud, talented, courageous, magnificent person who loves writing and wants to share my knowledge and understanding with you.