The best soil for a raised garden bed

The best soil for a raised garden bed

by Comments (39)

This post may contain affiliate links. If you click on an affiliate link and make a purchase, we receive a small commission at no extra cost to you. Find our full disclosure here.

One of the major benefits of gardening in a raised bed is you get to control the soil. This is especially advantageous for those whose property has hard-packed or clay soil, issues with tree roots, or concerns about pollutants. And since good soil is the foundation of a healthy garden, you want to make sure you’re setting your veggies up for success. So, what is the best soil for a raised garden bed?

Raised beds can be any size, but for a standard, rectangular bed, I recommend about three to four feet wide by six to eight feet long and 10 to 12 inches high. Those dimensions allow a gardener to reach in to plant, sow, and weed, without having to walk through it. This leads to another benefit in comparison to gardening in-ground in traditional rows. The soil in a raised bed will remain loose and friable, rather than being hard-packed over time by footsteps. We also know there is a whole web of micro-activity happening, so it’s best not to disturb and compact the soil for that reason, too.

How much soil do you need?

Filling a raised bed will likely require more soil than you think. A soil delivery might make the most sense economically. However, if it’s not practical logistically, you’ll need to purchase it in bags. You could also find an area in your yard from which you can move topsoil. There are some great soil calculators online that can help you figure out the amount you need.

If you happened to cut out the sod underneath where your raised bed will go, flip the pieces, grass-side-down to fill the bottom of your raised beds. There is lots of soil attached and the grass will break down over time. This also means you’ll require less soil to fill the raised bed.

If you dug up sod to make room for a raised bed, flip the pieces upside-down and use them to fill the bottom.

If you dug up sod to make room for a raised bed, flip the pieces upside-down and use them to fill the bottom.

The best soil for a raised garden bed

When I built my raised beds, I called around and ordered what I thought would be a good-quality triple mix. In Ontario where I live, triple mix is generally top soil, compost, and peat moss or black loam. A 50/50 mix seems to be more common in the U.S., which is a blend of top soil and compost.

If you’re ordering a soil delivery, try to find out where your soil has come from. Topsoil is often taken from land being developed for new subdivisions. It might have sat for a long time and can be devoid of nutrients.

If you’re purchasing bags of soil, look for labels like organic vegetable and herb mix or organic garden soil for vegetables and flowers.

Whatever you end up using, you want to make sure you amend it with compost. All that rich organic matter is an important component that will hold moisture and provide nutrients to your plants. Compost is an essential ingredient in the best soil for a raised garden bed, no matter which mix of ingredients you choose.

I filled my beds with about 3/4 triple mix, and even though it had compost in it, I top-dressed the garden with about ¼ compost. If you don’t have a compost pile, there are all sorts different types of compost on the market. Garden centres sell everything from mushroom or shrimp compost, to composted manure or bags labelled “organic vegetable compost.” Your municipality might even have free compost giveaway days in the spring.

Amending the soil in your raised bed

If you don’t have a compost pile, keep some compost on reserve throughout the gardening season. If you’re pulling out your spent pea plants mid-summer, not only are you removing a bit of earth, but those plants will have depleted the soil of nutrients. Topping up your beds with compost will add nutrients back into the soil to prepare it for whatever you plant next.

I like to add chopped leaves into the soil in the fall. Run them over with your lawnmower and sprinkle into your beds to break down over the winter. I have a compost pile where all the other leaves go. When they’re ready, I’ll use the leaf mould to spread in my gardens. To maintain the health of even the best soil for a raised garden bed, adding organic matter every year is essential.

In the springtime, I also will amend the soil with compost. I find the soil levels in my raised beds are usually lower from the weight of the snow. This fills them back up to the top.

Additional soil tips

  • If you have smaller containers to fill, check out Jessica’s recipes in her DIY potting soil article
  • It’s a good idea to do a soil pH test from time to time, so you can make the necessary amendments that will help your crops to flourish.
  • Growing cover crops is also a great way to add nutrients back into the soil.
  • If you are growing berries, like strawberries and blueberries, which like a more acidic soil, you can purchase soil that’s been specially formulated to grow them, or adjust the level with elemental sulfur or aluminum sulfate.

Looking for raised bed inspiration?

Pin it!

Find out the right soil for filling your raised beds

Related Posts

39 Responses to The best soil for a raised garden bed

  1. Hayley says:

    I bought several bags of garden soil and filled my raised bed before reading here and elsewhere that other blends should be used. My veggie plants seemed to be doing fine before being completely wiped out by some hungry critters. I’ve started some new seedlings and was wondering if I should replace the garden soil (or add compost or something else) before I plant the new seedlings.

    • Tara Nolan says:

      Hi Hayley, I like to amend my soil with compost a couple of times throughout the season to add some nutrients back in. Don’t worry about replacing it! Just keep adding in the organic matter. 🙂

  2. Fola says:

    Thank you for this post. I just started gardening last year and I have a garden bed. I purchased my garden soil from a landscaping company but my vegetables didnt turn out great, I am not sure if it’s the soil or due to lots of rain we had in Edmonton. I added a bit of compost to the garden bed in the Fall and covered up all winter. Would you recommend that I add more compost to it now before planting and what storebought compost would you recommend. Should I also be adding fertilizer to my seeds after planting?. Many thanks

    • Tara Nolan says:

      Hi Fola, It could have been the weather. If you amended with compost in the fall, your bed should be ready to go. When I buy compost, I usually grab whatever is cheapest at the time – shrimp, mushroom, compost that says it’s for veggie gardens. I’m not partial to one brand. You could add a slow-release organic fertilizer into the soil at planting time. I usually wait until the veggies get going, and then add organic compost according to the package directions.

  3. Wendy says:

    I am placing a raised bed over a garden area that I’ve used for years and added compost, etc. I’m wondering why I can’t just use that soil and amend it to make it lighter. What do you think?

  4. Monica Bogue says:

    we are making 4 raised beds right now. Can we just use compost to fill them up or do I need to add top soil.

    • Tara Nolan says:

      Hi Monica, you need to add a blend of soil and compost. A general rule of thumb is 30 percent compost. Where I live, triple mix is generally a mix of topsoil, peat, and compost (in the US, it’s a 50/50 blend). I still added an inch or two of compost once I filled my beds.

  5. Claudette L. Pitre says:

    I just put down 24 bags of Miracle Grow garden soil in a raised bed that I just made. (4 feet by 12 feet) I am in the process of building another one right now. But, I am thinking, now that I have read these comments, that I should have purchased raised bed soil instead. What would you suggest I purchase for the next raised bed? I could still pull some soil out of the other bed to mix with something else, if that would be best. I read that regular garden soil packs down and I can see that it has. Thanks.

    • Tara Nolan says:

      Hi Claudette,
      Miracle Grow sells lots of different soil mixes, so it’s possible the one you chose is just fine for growing veggies in raised beds. Any soil that’s formulated for veggie growing will do. To fill my raised beds, I had a delivery of triple mix, which is generally topsoil, peat, and compost. I then top-dressed with about two inches of compost.

  6. Ann Welch says:

    I bought bags of soil, compost, and peat moss for a 2′ by 12′ by 15″ raised bed, roughly one third of each to reach the recommended 30 cubic feet. How do I layer or mix these in my raised bed?

    • Tara Nolan says:

      Hi Ann, you can evenly mix them all in there together. And then don’t forget to top-dress with compost later in the season if you are succession planting, or in the fall or spring before you plant next year’s crops!

  7. Jessica says:

    I’m a newbie and I used more top soil than compost. (Like 95% top soil) It’s been a month since I transplanted my seedlings and I have no growth. Do you think it’s the soil? I regularly water my raised beds and I live in Florida so they are getting plenty of sun. ☀️ I’m searching for answers or maybe I just need patience 😆

    • Tara Nolan says:

      Hi Jessica, it’s possible that your soil is lacking in nutrients. You could try adding organic fertilizer. Be sure to read the instructions carefully. 🙂

  8. David says:

    Hello, I’m new to this raised bed gardening. I live in Northern Alberta (North of Edmonton), and built 24 inch high bed so I can still garden without having a sore back!

    What would you recommend for layers of soil in the beds? 2 feet of topsoil, or do I need to put different layers of various soil types in the bed?

    I have built 4ft wide by 40 ft long raised bed in sections.

    Thank you for your inspiration.

    • Tara Nolan says:

      Hi David, to save money, on the very bottom you could fill it with sticks and dry leaves so you don’t need as much soil. Top soil would work, too. But the areas where the roots of your plants will be extending into (at least 10 to 12 inches down), you want good-quality vegetable soil. You could top-dress this with compost. 🙂

  9. Elizabeth Friesen says:

    I appreciated this article. I am new to the game and quite nervous that my veggies won’t grow, so any tips and tricks would be appreciated. Can you buy the PH test at any garden center? Also, I’m in zone 5 and my south exposure raised garden should get at least 6-8 hours of sun per day.

    • Tara Nolan says:

      I’m not sure that every garden center will have tests, but sometimes municipalities offer them. I wouldn’t worry so much about a test if you’re starting with a soil delivery. Order good-quality soil formulated for vegetables (not top soil) and top-dress with compost. 6-8 hours is perfect!

  10. Michele says:

    I bought the organic miracle grow in ground soil by mistake for my raised garden bed is it okay to use it?

    • Tara Nolan says:

      Honestly, I’m not sure what’s in that particular type. I would compare its mix of components with the one you intended to buy. The fact that it’s organic is promising!

  11. Juanita says:

    I’m starting my first raised vegetable garden and I purchased G&B Organics Harvest Supreme premium soil amendment with 15% chicken manure. Should I mix anything with it? I’ve put down weed control fabric at the bottom of the bed.

  12. Tara Nolan says:

    Hi Juanita,
    Looking on their site, it says to mix it with your native soil. Amendments are great to add to your existing garden beds if they are already filled. I see G&B also sells a Raised Bed & Potting Mix, but you could also find a 50/50 blend and add your amendment to it.

  13. Tanya says:

    I am new to all this and setting up new raised gardens beds….I have seen people suggest to put a layer of cardboard down first… with some leaves and grass… then put the soil/compost mix over that… the cardboard, grass and leaves will break down over time and create a compost underneath.. is this something you would recommend?

    • Tara Nolan says:

      Hi Tanya, the cardboard layer can be used to break down grass if you’re putting the raised bed over top. Some people will use leaves and sticks so they don’t have to use as much soil. And these will break down over time, creating compost. I have done this step myself when filling raised beds. 🙂

  14. Christi says:

    Is top soil that says lawn and garden soil conditioner okay to use to fill a raised garden bed? I purchased this topsoil and didn’t notice it says “conditioner” on the bag. I’m mixing with composted manure and potting soil.

    • Tara Nolan says:

      Hi Christi, I’m not sure what’s in your soil conditioner, which I imagine is used to amend existing soil, but if it’s a peat-based product and you’re mixing it with the manure and potting soil, it should be okay.

  15. Ben says:

    Hi Tara,

    Another good calculator is https://soilcalculator.com. I like it a bit better than the one you posted because it shows exactly how many bags are needed.

    Diego

  16. Max says:

    Hey I am a brand new gardener who created an 8×4 raised bed in my back yard. I went to the store and bought 5 bags of top soil and 3 bags of compost. I am unsure on how to put them in the bed in order to get the best veggie production. Do you have any tips?

  17. Rhonda Watson says:

    Do you need any type of drainage for planter boxes? My box is layered with a weed barrier and has open slats. It I’d a Vreuge raised planter box from Costco.
    Thank you

    • Tara Nolan says:

      By the sounds of it, the open slats should allow for drainage and the weed barrier should be permeable, allowing the water to drain out the slats. 🙂

  18. RICARDO ANTONIO PÉREZ says:

    Thank you kindly for being so generous with your time and sharing your knowledge with us.

  19. Janice says:

    I have 2 garden boxes (2’x6′ each). This will be my 3rd year for trying to do garden. I first year I got compost soil and nothing really came except for a few beans. Last year I added some sheep manure and tilled it up. It was even worse. What could I add this year? I’m hoping that I do not need to empty all the soil and start over.

  20. samantha osuna says:

    Hi Tara,
    My hubby just built a length of 70inches, width 35 inches, and depth of 15inches. I was going to buy compost(chicken/steer manure compost), vermulite/perlite, peat moss, and top soil. What would you recommend for ratios? Or can I purchase Kellog organic raised bed soil?

    Thank you!
    Sam

  21. Ruchi says:

    HI Tara, I live in Ontario as well and was starting my first raised vegetable bed this year. Trying to keep an average budget, was planning to make my own mix and buy 50% top soil, 30% compost and 10% pea moss after doing quite a bit of reading since I am nervous about this going in the first time. Does the mix sound good? I also just read that peat moss once dried doesn’t rehydrate. Your thoughts pls… thanks!

    • Tara Nolan says:

      Hi Ruchi, If you can find a triple mix, rather than top soil, that might be a bit better. Usually it’s a mix of top soil, compost and peat. I used about 70-80% triple mix for my raised beds and 20-30% compost. 🙂

Leave a Reply

Your email address will not be published. Required fields are marked *