For plants, soil provides another vital element. It doesn’t just deliver nutrients to hungry fruits, vegetables, and flowers; good garden bed soil increases the airflow around plant roots to avoid compaction and improve drainage as it retains moisture for basic hydration.
Gardening with raised beds provides more control over the soil. However, the best soil for raised beds depends on the plants you want to grow. Many soil types are suitable for a variety of uses, while others are more specific in their purpose. Read on for some of the top soils for raised beds and some things to keep in mind as you shop.
- BEST OVERALL: Miracle-Gro Potting Mix 2 cu. ft.
- RUNNER UP: FoxFarm FX14047 Happy Frog Potting Soil
- BEST BANG FOR THE BUCK: Mountain Valley Minute Soil – Compressed Coco Coir
- BEST ORGANIC: Organic Plant Magic Compressed Organic Potting-Soil
- BEST TOPSOIL: Michigan Peat 5540 Garden Magic Top Soil
- BEST COMPOST: Charlie’s Compost 10lb
- BEST PEAT MOSS: Hoffman 15503 Canadian Sphagnum Peat Moss
- BEST VERMICULITE: Professional Grade Vermiculite by Plantation Products
- BEST FOR VEGETABLES: New Coast of Maine – Organic Raised Bed Mix
- BEST FOR HERBS AND FLOWERS: Miracle-Gro Raised Bed Soil
What to Consider When Choosing the Best Soil for Raised Beds
Growing flowers and food in a raised garden bed differs from growing them directly in the ground. Consider these key points before dumping dirt into your raised beds.
Raised Bed Height
Knowing the size of your raised bed garden will help you determine how much soil you will need to fill it. Thankfully, there are plenty of useful calculators that can help with this task, taking into account shape and dimensions. In general, the taller the raised bed, the more raised bed soil you’ll need.
Taller raised beds or tabletop designs can eliminate back strain and make gardening more comfortable. Alternatively, you can fill the bottom of a tall ground-level bed with filler like dead leaves or cardboard to minimize the amount of raised bed soil mix you’ll need.
Plant Type and Root Depth
The plants grown in the garden will determine the best raised bed soil depth needed for optimum growth. Generally, a good rule of thumb is to build a raised bed that’s at least 6 inches deep. This depth allows for drainage and retains moisture at levels needed for many common crops. However, some plants have deeper roots than others. For example, if you plan to grow root vegetables like carrots, a depth of 12 inches is preferable.
Raised beds are great for any kind of plant but work particularly well for growing vegetables. Elevating the growing space keeps weeds at bay and the soil warm and prevents compaction. Gardeners also get to start with pristine, neutral-pH soil. However, if you’re using previously used soil, do a soil test to determine whether you need any amendments or fertilizer to renew the nutrients.
Many gardeners have tried-and-true soil mix recipes, but in general, it’s best to avoid settling for uber-cheap bags of raised bed soil. A good soil mix contains topsoil, a small amount of substrate, and a significant amount of compost, which contains nutrients that improve soil conditions.
The least expensive bags of soil are usually low quality and full of weed seed, debris, and other nasty contaminants. They’re also unlikely to contain many valuable nutrients.
Topsoil is basically filler soil needed for everything from raised bed gardening to indoor potted plants. It makes up the bulk of most raised bed soil mixes. It’s not very rich in nutrients but is a necessary component that contains organic matter.
The substrate makes up a small percentage of the raised bed soil mix but is extremely important. It helps control moisture content, which is key in a raised bed. Some of the substrates that might appear in soil mixes include peat moss, rock phosphate, vermiculite, perlite, and coco coir. Again, the type of plants you choose to grow will help determine the appropriate substrate to support them.
Be careful to avoid adding too much peat moss, which can increase the acidity of the soil and throw off the pH balance. Some gardeners prefer to fill raised garden beds with a topsoil-free mix, using equal parts compost, perlite, and coco coir. It makes for a fluffy, moisture-retaining growing medium.
Compost from multiple sources is best because it provides a wide variety of nutrients. It can even come from your own backyard pile that consists of leaves, grass clippings, and other yard waste.
In the world of soil, the term “organic” refers to organic materials such as compost and mulch. “Nonorganic” materials aren’t necessarily harmful. They’re just inert and include things like pebbles, rock phosphate, and perlite. Nonorganic soil that contains no organic matter lacks nutrients but is also free of contaminants. When the terms are used in this way, the term “nonorganic” doesn’t mean synthetic fillers or chemicals; it means that the substances are not nor have they ever been alive.
However, the term “organic” can also mean free of synthetic chemicals and pesticides. The USDA’s National Organic Program (NOP) covers farm practices, including soils and other substances applied to crops like organic fertilizer. In addition, the Organic Materials Review Institute (OMRI), a volunteer organization, lists products that organic farmers can use to produce food. Both the NOP or OMRI list possible soils, amendments, and fertilizers that can be used and still maintain an “organic” garden.
Topsoil isn’t the same as garden soil. As the name suggests, it’s the top layer of soil. This general-purpose soil is ideal for filling in garden beds or preparing a bare lawn for growth.
It’s not very nutrient-rich, but it contains important organic matter, so it’s not entirely useless. If you buy topsoil bags and plan to use them to fill your raised beds, pour the topsoil in first since this soil makes a great base layer and filler. Then cover the topsoil with a more nutrient-rich mix of compost, peat moss, and substrates that will nourish the plants.
The best raised bed soils contain nutrients that fuel growth. Organic, natural fertilizers include compost, sea kelp, and worm castings. These fertilizers enhance the quality and condition of the soil without you having to worry about contamination. The slow-release properties of organic fertilizers prevent potentially harmful buildup and ensure that your plants aren’t harmed by a flood of nutrients all at once.
Some raised bed soil mixes may contain synthetic fertilizers. They provide a quick nutrient boost but don’t improve soil condition and texture like organic options. This is why it is best to choose or make a soil mix with organic nutrient sources.
Our Top Picks
Here are some soil recommendations to help fill raised garden beds. There are specialized soils as well as general mixes to help plants thrive, including soils from brands long trusted in the gardening world. All you’ll need to do is slip on your gardening gloves, open up the bags, fill up your beds, refill your watering can, and get growing.
Miracle-Gro has earned a strong reputation in the gardening world with a wide range of gardening soils, fertilizers, and amendments. The Miracle-Gro potting mix offers a blend of nutrients from a wide range of sources, including processed forest products, peat, coir, compost, meat moss, perlite, fertilizer, and wetting agents.
The compost content has a variety of sources that may include animal manures, composted leaves, grass clippings, or composted bark.
The wide range of ingredients provides an equally varied nutrient base that can nourish an assortment of plants. The diversity and inclusion of perlite prevents compaction while improving drainage and aeration. Once applied over quality topsoil, this Miracle-Gro garden soil mix has the nutrients to support plants for up to 6 months.
- Ingredients: Peat, coir, compos, sphagnum peat moss, perlite, fertilizer, and wetting agents
- Quantity: 2 cubic feet
- Organic: No
- Provides drainage and aeration
- Resists compacting
- Supports plants for up to 6 months
- Suitable for indoor and outdoor use
- Some users report insect infestations
- Limited quantity compared to similar options
Get the Miracle-Gro mix on Amazon and at Ace Hardware.
The FoxFarm potting soil contains a mix of microbes with mycorrhizal fungi and sediment. The fungi content enhances the nutrient uptake of the root system by creating a symbiotic relationship with the root mass. Essentially, it expands the root’s reach, promoting their development.
That fungi content gets balanced with sediment that maintains the light texture and aeration needed to let plant roots expand as they consume nutrients. The mix contains a pH balance for optimal growth that’s supportive of fruit, vegetables, or flowers. On the downside, this mix holds moisture so well that in certain humid conditions, it may begin to grow mold.
- Ingredients: Mycorrhizal fungi and sediment
- Quantity: 2 cubic feet
- Organic: Yes
- Promotes root development
- Supports fruits, vegetables, and flowers
- May grow mold in high humidity
- Limited quantity compared to similar options
Get the FoxFarm potting soil at Amazon, Target, and Walmart.
Mountain Valley Minute Soil Compressed Coco Coir Fiber Grow Medium squeezes nutrients down to a compact brick full of goodness. Made of raw coconut coir, this fibrous block expands to a light texture designed to aerate and it retains moisture. At the same time, it provides a nutritious boost for topsoil.
Gardeners can rehydrate the entire block to create 15 gallons of soil or hydrate only the amount needed for a specific project. The compressed packaging stores easily and provides options for a wide range of gardening needs and uses. These compressed blocks come in several sizes to suit most gardener’s available storage space.
- Ingredients: Compressed coco coir
- Quantity: 15 gallons
- Organic: Yes
- Moisture-retaining and lightweight
- Compact and easy to store
- Comes in multiple sizes
- Suitable for flowers, plants, and herbs
- Some users report poor growth
Get the Mountain Valley minute soil on Amazon.
Organic Plant Magic Compressed Organic Potting Soil for Garden & Plants contains natural, organic ingredients to feed and nourish plants. This compressed soil can be rehydrated and used as the nutrient layer or applied directly to existing soil without rehydrating. This dry, organic mix alone holds 50 percent more water than regular soil, which is one reason it works so well for raised beds.
The soil contains natural coconut coir, worm castings, mycorrhizae, helpful bacteria, amino acids, and humic acids. These ingredients work together for a slow release of nutrients so that plants don’t get overwhelmed. This package requires 12 cups of water to create 2 pounds of compressed soil. The mixture then expands to create 3 gallons of usable soil.
- Ingredients: Coconut noir, worm castings, mycorrhizae, and amino and humic acids
- Quantity: 3 gallons
- Organic: Yes
- Holds 50 percent more water than regular soil
- Slow release
- Can be used on existing soil
- Easy to store and rehydrate
- Does not come in multiple sizes
- Pricey compared to similar options
Get the Organic Plant Magic soil on Amazon.
Topsoil fills a raised bed rather than nourishing the plants in it. The Michigan Peat top soil does that with a mix of reed sedge peat and sand. For gardeners who are using dirt from the natural landscape, this garden soil mix can loosen heavy clay soils and improve the water retention of light, airy soils.
Sometimes topsoils can arrive with twigs and debris that aren’t harmful but don’t help your garden. The Michigan Peat topsoil (usually) arrives without clumps or these surprise additions, sticking with pure ingredients. However, a word of caution—bags have been known to arrive with stowaways such as frogs.
- Ingredients: Reed sedge peat and sand
- Quantity: 4 pounds
- Organic: Unlisted
- Works well with heavy clay soils
- Increases water retention in light soils
- No clumps, twigs, or debris
- Some bags may attract insects or frogs
Get the Michigan Peat top soil on Amazon.
Charlie’s Compost has natural ingredients composted and ready for plants to soak up nutrients. It contains a garden soil mix of chicken manure, cornstalks, forest products, hay, straw, clay, and microbe inoculants. Before being bagged, the ingredients are composted for 8 to 12 weeks, at which time they’re ready for application to the garden.
The blend works well when mixed with other soils or as an additive around plants. If used in direct contact with plants, be sure to use it sparingly: It’s powerful enough to burn delicate plants. There have also been (rare) instances of bags arriving with ingredients that aren’t completely broken down.
- Ingredients: Chicken manure, cornstalks, forest products, hay, straw, clay, and microbe inoculants
- Quantity: 10 pounds
- Organic: Yes
- Composted for 8 to 12 weeks
- Powerful formula
- Safe to use in direct contact with plants
- May be too strong for delicate plants
Get the Charlie’s Compost soil on Amazon and at Sears.
Hoffman 15503 Canadian Sphagnum Peat Moss contains 99.8 percent natural ingredients, consisting almost entirely of natural peat. This mix helps break up compacted soils, aerate roots, and improve drainage. However, the peat also holds water for better moisture retention in a raised bed setting.
This bag provides a big bang for the buck. It’s meant to mix with other soils, so even in a large raised bed, it can go a long way. Keep in mind that heavily compacted soils will require more peat to loosen the soil than light, airy soils.
- Ingredients: Peat moss
- Quantity: 10 quarts
- Organic: Yes
- Provides ample drainage and aeration
- Breaks up compacted soils
- Heavily compacted soil may require more of this mix
Get the Hoffman peat moss on Amazon.
The Professional Grade Vermiculite by Plantation Products contains a mix of vermiculite grades, fine to coarse, in one mix. However, it tends to contain more fine-grade particles, which makes a difference in the plants for which it works best—mostly, plants that prefer a high moisture content. With the right soils, it can be used to improve aeration and keep plants well hydrated.
This vermiculite provides adequate moisture levels for seedlings, too. However, the fine grade doesn’t take much moisture to keep plants healthy. Gardeners need to know their plants and soil mixes well when using this vermiculite. In some cases, it can retain too much moisture for plants that are easily overwatered.
- Ingredients: Vermiculite grades
- Quantity: 8 quarts
- Organic: Unlisted
- Fine and coarse vermiculite
- Suitable for seedlings and plants that need high moisture contents
- Promotes aeration
- May provide too much moisture for some plants
Get the Plantation Products vermiculite on Amazon.
New Coast of Maine – Organic Raised Bed Mix nourishes plants with natural ingredients designed for plants meant for human consumption. That doesn’t mean it can’t work well for flowers and inedibles, but when it comes to vegetables, organic ingredients assure top nutrients. It’s OMRI listed, providing an extra layer of assurance that ingredients meet requirements to qualify as natural and organic.
This raised bed mix contains cow manure compost, bichar, worm castings, dehydrated poultry manure, kelp meal, lobster meal, greensand, lime, and mycorrhizae.
A wide and varied mix of ingredients balances pH and provides nutrients for an equally diverse range of plants. Keep in mind that this soil is designed specifically for outdoor raised beds. It’s not one to use with indoor potted plants because it won’t provide the right moisture retention or nutrients.
- Ingredients: Cow manure compost, bichar, worm castings, dehydrated poultry manure, and more
- Quantity: 1 cubic foot
- Organic: Yes
- Specially designed for outdoor raised garden beds
- Safe to use for vegetables, fruits, plants, and flowers
- OMRI listed
- Balanced pH
- Not suitable for indoor use
- May attract insects and pests
Get the New Coast of Maine mix at Amazon, Target, and The Home Depot.
The OMRI-certified Miracle-Gro Raised Bed Soil provides organic matter needed for good drainage while growing flowers, herbs, vegetables, and fruits. The raised bed soil requires no mixing. Designed specifically for raised beds, the premixed blend comes in 1.5 cubic foot bags. It takes about three bags to fill a 2-foot by 2-foot bed that is 1 foot high.
- Ingredients: Sphagnum peat moss, compost, worm castings, alfalfa and kelp meal
- Quantity: 1.5 cubic feet
- Organic: Yes
- Specially formulated for raised beds
- Controls weeds and pests
- Certified by the Organic Materials Review Institute
- Does not control moisture
- Not suitable for indoor plants
Get the Miracle-Gro soil at Lowe’s and Walmart.
A reliable soil for raised garden beds that provides ample drainage and aeration, we recommend the Miracle-Gro Potting Mix. This soil mix contains peat, coir, perlite, fertilizer, and more and can be used indoors and out for over 6 months. Alternatively, for a budget-friendly option, the Mountain Valley soil comes in a compact brick that expands to over 15 gallons of moisture-retaining and lightweight soil for raised garden beds.
How We Chose the Best Soil for Raised Beds
We researched the most sought-after soil for raised beds in their respective categories and discovered that the best options are determined by their ingredients, quantity, versatility, and other special features included by top brands.
While searching for the best garden bed soil, we found that the most popular types among users were the ones made with organic materials including peat, coir, perlite, worm castings, compost, and more. Many of these mixes are formulated to provide drainage and aeration and select options can be used for indoor and outdoor plants, vegetables, fruits, flowers, and herbs.
Whether you need 1 cubic foot or over 15 gallons of soil, the above list includes options that resist compacting, are pH-balanced, and can be used on existing soil with grown plants as well as seedlings.
If you still have concerns about filling your raised beds with the best soil, here are the answers to a few common questions about soil for raised beds.
Q: How many soil bags do I need for a raised bed?
It depends entirely on the size and shape of the raised bed. If you know your garden bed’s dimensions, you can plug them into a soil calculator to find out how much you need.
Q: How do you prepare soil for a raised bed?
If you’re buying potting soil in bags, it’s typically premixed, so there’s not much to do other than water it before planting. Topsoils that act as fillers require you to layer substrate and/or compost on top. Once you’ve done that, it’s all about water. Watering the soil prior to planting, using either a watering can or a garden hose, ensures your plants have enough moisture to start growing.
Q: Is topsoil good for a raised bed?
A topsoil product is a great filler, but it’s not designed to be the main nutritive soil in a raised bed. The plants need nutrients, and topsoil is not rich in organic matter like compost or potting soils.
Q: Can I use only compost for a raised bed?
Yes. In fact, the Square Foot Gardening Foundation recommends a compost-only option for gardeners on a budget or those who don’t have access to other mix-ins. However, while this can be cheaper (if you have access to free compost), the soil in a compost-only bed can become compacted.