Introduction

Raised bed gardening could be overwhelming for beginners. After you’ve built your raised garden bed structures and planned out the crops you want to grow, it’s time to come up with a good soil mix. If you need topsoil for making your own soil mix, you can search for “topsoil near me” and buy some from the nearest store. Let’s check out the best soil mixture for raised beds.

The Details

1. Building soil mixture for raised beds – While you can buy pre-mixes from various brands on the market to fill up your raised garden beds, you can make a much better option at home without spending as much. You won’t just get a superior mix, but a healthier soil that will stimulate the growth of a delicate ecosystem to benefit your harvest and make it more nutritious.

Moreover, building great soil is a gradual process that will take you a few years over many growing seasons. However, when you’re filling up your garden beds for the first time, it’s best to amend all the best ingredients for a healthy soil foundation. Let’s check out those ingredients.

2. 50 percent high-quality topsoil – High-quality topsoil would make the bulk of your beds for obvious reasons. Buy high-quality topsoil bags from trusted brands and check out the ingredients on the label. If you’re starting a big project with multiple stacked garden beds, it’s best to buy in bulk from a local reputable landscape supplier. Ask questions about the things that go into the topsoil and where it is sourced from. Smell the soil, inspect it and give it a squeeze test before buying. 

The squeeze test refers to taking a handful of soil in your hand and squeezing it to inspect the soil structure. High-quality topsoil should hold together and eventually break apart as you run your finger through it. If the soil is too hard to break apart or too sticky, it shouldn’t be used for your bed. On the other hand, if the soil is too sandy, it would have a hard time holding together. High-quality topsoil isn’t sandy or sticky and should have a dark-brown appearance with an earthy smell. 

3. 30 percent homemade compost – If you’re experimenting with a couple of raised garden beds, sourcing 30 percent compost from your own backyard wouldn’t be an issue. However, if you’re planning a large project, you need to get what’s available from your compost bin and source the rest from a reputed supplier.

When you buy compost, it’s important to note that all compost isn’t created equal. Talk to your compost supplier and ask where the feedstock that made the compost came from. Inquire about the materials the supplier accepts for compost fuel and the things they don’t. Inspect their compost-making procedure. Use your common sense and if the supplier is shady, it should raise quite a few red flags.

Otherwise, you can just pay a bit more and get Certified Compost. Certified Compost is a regulated term. You’ll find information about certified compost on the website of the US Composting Council and also access their database with listed compost members. Make sure that you don’t go overboard. Stick to the 30 percent mark. The rest of the 20 percent of your raised bed mix would need other amendments. Let’s check them out.

4. The 20 percent cocktail – After you’ve mixed 50 percent high-quality topsoil with 30 percent compost, you’re free to add the rest of the amending materials according to your requirements. Some people like to add shredded and aged leaves since they are free and add bulk to the mix while adding a lot of nutrients. Even if you don’t have a lot of leaves in your yard, ask around the neighborhood and most people would be more than happy to get rid of the raked stash they have been accumulating.

Some resourceful gardeners also add mineralized soil blends to their soil mix. It’s basically soil with added minerals. This kind of soil is usually locally sourced by reputed suppliers and the mineral makeup depends on your geographic location. For instance, if you live in the Atlanta region, granite is abundant, and that’s why mineralized blends would contain a lot of granite dust.

Apart from that, there are worm castings, mushroom compost, and ground bark that can be added to the cocktail. You’ll see a dramatic difference in your harvest with worm castings added to the soil. Worm castings contain a ton of primary nutrients to make your plants thrive. Compared to natural topsoil, they have five times the nitrogen, ten times the potassium, and seven times the phosphorus. Adding a little bit will go a long way. If you like to grow your own mushrooms, you can use the byproducts left over from the harvest in the cocktail.

5. Things not to add to your soil mix – While there are numerous other ingredients that you can add to your raised bed soil mix, you need to avoid certain materials. Artificial filers stay at the top of the list. Even if you get organic fillers, they will break down over time and sink your garden bed, prompting you to add more soil later on.

You should also avoid peat moss. Despite being high in nutrients, it isn’t sustainable since it takes hundreds of years for peats to form in peat bogs. Moreover, peat moss can also reduce your soil’s ability to absorb moisture. Horse manure is another amending material that you need to stay away from. If you’re not careful, it can burn the plant roots and bring you years of grief if it comes from a bad source.   

Conclusion

Making your own soil mix for your raised garden bed isn’t too difficult. You just need to be mindful of the things you put into the mix and adopt practices to maintain the health of the soil in your raised garden beds. If you need to buy topsoil for making your own mix, you can search for “topsoil near me” and buy some from a store nearby.