Several soil mixes work well for raised garden beds. They all have one thing in common: they’re made of a blend of ingredients. The specific blend varies depending on whether you want to grow vegetables or flowers and whether you want to use chemical fertilizers or organic fertilizers.
The first thing to decide is how much work you will put into your garden. If you want a simple mix that requires no watering and little maintenance, you can use a combination of compost and topsoil from the local nursery. But if you’d rather spend less time working in and maintaining your garden, consider using a more complex mix with added fertilizer or manure.
Compost is made from the dead plant material and can be made at home or purchased from a store. It contains plant nutrients, such as nitrogen, phosphorus, and potassium. Compost also contains microorganisms that help plants grow.
Compost improves the texture of the soil by adding organic matter to it. Organic matter helps water drain through the soil and improves aeration by adding space between soil particles. It also provides food for microbes living in the soil that help break down organic matter into nutrients that plants can use.
Because compost contains so much organic material, mixing it with other types of soil is important to ensure that it doesn’t become too dense or compact over time. A mixture of compost with some native soil will give your garden bed good drainage and fertility while keeping its structure intact. If you don’t have any native soil available, mixing compost with peat moss or sawdust can help increase the porosity of your soil.
Bagged topsoil is one of the most common types of soil used in raised bed gardening. It is typically made up of soil that has been screened and graded so that it contains various sizes of particles. This makes mixing with other materials like compost and fertilizer easier because it helps them spread more evenly throughout the whole mixture.
You can buy bagged topsoil by itself or mixed with other amendments like compost or peat moss. The more amendments added, however, the less likely you’ll get something organically certified (more on this later).
If you do decide to purchase bagged topsoil from a local nursery or garden center, you should ask them if they offer any discounts for bulk purchases or if they sell in bulk quantities already mixed with compost or other amendments.
Peat moss is a type of soil amendment made from sphagnum moss. It can be used as a soil conditioner and lightening agent in potting mixes, seed starting mixes, and other types of potting media. It’s also used as a soil amendment for raised beds and container gardening.
Peat moss is an important ingredient in many types of compost because it helps retain moisture and soil nutrients. It also provides aeration so that oxygen is easily accessible to plant roots.
Peat moss is naturally acidic when it comes out of the bog, but adding lime can help reduce this acidity if necessary for your plants’ needs.
If you’re growing vegetables that require alkaline soil, such as potatoes and onions, you may want to add peat moss to your garden bed to help raise its pH level.
Vermiculite is a mineral that has been mined since the 1930s. It’s made from mica, which is an igneous rock. Vermiculite is used in gardening to add drainage to soil and help it retain moisture. It also improves aeration by acting like a sponge when damp, allowing oxygen to reach plant roots.
Vermiculite has many uses in gardening because of its ability to hold water and air. When added to soil, vermiculite increases drainage, absorbs excess water, and helps retain moisture around plant roots. This makes it ideal for growing plants that need consistent moisture but requires well-drained soil, such as tomatoes, roses, and many types of flowers.
Vermiculite also improves aeration by acting like a sponge when damp, allowing oxygen to reach plant roots. Adding vermiculite to soil can help prevent compaction by improving the structure of your garden beds, so they drain more efficiently and allow air circulation around roots for healthy growth.
This is the best choice if you’re planting annuals and vegetables that won’t be around for more than one growing season. Potting soil is light, fluffy and well-drained, which makes it great for quick growth. It’s also inexpensive, so you don’t have to spend much on the soil if you only plan to grow something for a few months. If your raised bed is empty for a long time between plantings (a year or more), then potting soil may not be the best choice because it can compact and become hard over time.
Humus soil is the best type of soil to use in raised garden beds. Humus is decomposed organic matter broken down into very small particles. It can be purchased at most garden centers or make your own by composting.
Composting is a process where plant materials are broken down into humus in a controlled environment. This is done by adding nitrogen-rich materials like manure, leaves, and grass clippings to the pile, along with carbon-rich materials like wood chips, cardboard, or paper products. It takes several months for the composting process to complete, and it can be used immediately as mulch or added to existing soil beds as an amendment.
When deciding what soil to use for your raised garden beds, it is important to choose soil that is well-drained and able to retain water and nutrients simultaneously. The native soils from your region will be best as generations of gardeners have thoroughly tested them. If the native soils are not ideal, we recommend using a commercial mix designed for raised bed gardening.