Whether you’re growing vegetables, flowers, or herbs in pots, it’s important to choose the right kind of soil. Here are tips on choosing the best soil for your container garden, including what to look for and what to avoid.
Who has gone to the garden center to start a veggie garden, and been completely flummoxed by all the choices you have to make? Containers, soil, seeds or seedlings…so many choices!
There are about half a zillion different types of soil at the garden center, and they won’t all work when you’re growing vegetables in containers. There’s lawn soil, garden soil, topsoil, soil conditioner, compost…what’s a gardener to choose?
Because your vegetables are growing in a confined space, their roots need to get all their nutrients from the soil you provide. Here is the info you need to be sure you’re buying the right kind of soil for your amazing container garden.
Garden Soil Shopping Tips
Friends, I’m not going to mince words regarding my recommendations for container gardening soil. Keep these tips in mind and then we’ll discuss the best choices for growing your vegetables.
Cheaper is not better. You’re growing food for your family, after all. Just as you can’t grow a healthy body on cheap junk food, you can’t grow nutrient-rich vegetables in fill dirt you get free from Craigslist, or generic bags of compost with no ingredients listed. And the really cheap potting soil could contain fungus gnats or other critters.
Please don’t use any products by Miracle-Gro. Although they are everywhere and inexpensive, they are a division of Monsanto (the company that makes Roundup). Glyphosate, the primary ingredient in Roundup, is a probable human carcinogen, and is banned in many countries. I cannot in good conscience support this company, and I urge you not to buy from them either.
Even if you aren’t concerned about Monsanto and Roundup, Consumer Affairs has an entire page dedicated to complaints about Miracle-Gro Potting Soil.
Best Container Gardening Soil
What kind of soil is best for your container garden? I strongly suggest buying potting soil or “container mix” soil from your local garden center.
I prefer organic potting soil because I know it’s free from pesticides or other chemicals. Good container mix soil will contain organic matter that provides nutrients, like worm castings, bat guano, manure or compost, seaweed, etc. It may have minerals like perlite or vermiculite to improve drainage, and peat or coconut coir to absorb water.
FoxFarm Ocean Forest Potting Soil is my favorite and I also like E.B. Stone Ultimate Recipe Potting Soil. Both of these are natural and organic, and contain lots of natural ingredients to encourage strong vegetable growth for a big harvest.
Types of Soil to Avoid in a Container Garden
While it might seem easier to just scoop up some dirt from your yard to put in your containers, this is not a good idea. Garden soil is too dense and could have fungus, microbes, seeds, bugs, or other critters that you don’t want in your containers.
I also don’t recommend buying potting soil with added fertilizer. This is more expensive, and I prefer to add the fertilizer that I choose, that’s best for my veggies.
If you’re reusing last year’s potting soil, be sure to add compost to return nutrients to the soil. Many people say you must buy new potting soil every year, but the book Decoding Garden Advice: The Science Behind the 100 Most Common Recommendations debunked that myth. They recommend buying fresh soil only if you know that the old soil carried disease, or if you’re growing a rare or heirloom plant.
And, as mentioned above, please don’t use Miracle-Gro.
How much soil do I need?
The size of the container determines how much potting soil you’ll need. You’ll want to fill your container to about an inch below the rim (not completely to the top), like this:
Don’t add rocks, packing peanuts, cans, or other items to the bottom of your container. While you might think these will improve drainage, they actually do not. My colleague Joe Lamp’l shows us why, in this short video.
If you think squirrels might dig in your containers, put a bit of netting or mulch on the soil to discourage them.
Neighborhood cats getting in your containers? Here are natural ways to keep cats out of your garden.
Read more about Container Gardening