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One of the major benefits of gardening in a raised bed is you get to control the soil that goes into it. This is especially advantageous for gardeners with a property that has hard-packed or clay soil, issues with tree roots, or concerns about pollutants. Since good soil is the foundation of a healthy garden, you want to make sure you’re setting your vegetables up for success. So, what is the best soil for a raised garden bed? In this article, I’m going to share some advice on figuring out how much soil you need, what to purchase, amending a soil delivery, and more.
One of the benefits of gardening in raised beds is that 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 in our soil, so it’s best not to disturb and compact the soil. A raised bed allows you to reach in to weed and plant.
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. There are some great soil calculators online that can help you figure out the amount you need.
There are some ways to fill in the bottom of a raised bed so you don’t need as much soil. For example, 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. There is lots of soil attached and the grass will break down over time. Or, if you’ve moved soil around to create a garden, you can use that for the bottom, provided you amend the soil on top accordingly.
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 centers 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, for example, 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 them 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 mold 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. A spring refresh fills them back up to the top.
Additional soil tips
- Discover the various organic garden soil amendments you can add to your raised bed.
- 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.
- If you have smaller containers to fill, check out Jessica’s recipes in her DIY potting soil article.
- Learn the difference between potting soil and garden soil.
- 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.
** I’ve also written a book about raised beds, Raised Bed Revolution, and created a course called Raised Bed Basics for Savvy Gardening School, both of which touch on soil, as well as lots of other advice.
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. 🙂
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.
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?
Tara Nolan says
Hi Wendy, I don’t see why not, if the soil is nice and loose and friable. 🙂
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.
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.
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!
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. 🙂
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. 🙂
T-Flor says
You can also use cardboard (think Amazon boxes or any sort of cardboard box, tape removed) or paper bags for the bottom and then, fill it up. Worms love the cardboard — they literally eat it up and poop it out and you’ll have done no work at all to get those great castings when they defecate.
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!
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!
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.
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.
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. 🙂
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.
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
Tara Nolan says
Thanks for the tip!
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?
Tara Nolan says
Hi Max, I would empty the top soil on the bottom and then the compost on top!
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. 🙂
RICARDO ANTONIO PÉREZ says
Thank you kindly for being so generous with your time and sharing your knowledge with us.
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.
Tara Nolan says
Hi Janice, you might want to consider a soil test to see what nutrients are lacking in your garden. This article might be a bit helpful, too. https://savvygardening.com/soil-ph-and-why-it-matters/
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
Tara Nolan says
If you’re making a mix, I would measure in thirds. Organic raised bed soil also sounds promising!
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. 🙂
Florilee Jowers says
If I use potting soil with fertilizer do I still need compost?
Jessica Walliser says
Yes. The compost will help with moisture retention and add beneficial microbes that can help your plants fight disease.
Kennedy says
I live in Ga and have red clay dirt so I’ve decided to do a 12×12 raised bed garden. I’ve read hours of info but still confused as to how and what. I have grinding from 4 tree stumps in my yard. Is that considered compost? If I use garden fabric is that over or under compost, then veggie soil then top soil? Appreciate any help for a newbie!
Tara Nolan says
Hi Kennedy, I think your ground tree stumps would be more of a mulch. Depending on the depth of your raised beds, you could use this on the very bottom of your raised beds to fill them a bit before adding the soil. I would avoid garden fabric, unless you’re trying to keep roots or weeds suppressed. If you do use fabric, it goes under everything. I would mix veggie soil, top soil, and compost. (1/3 of each)
Peyton C. says
Hello! We have recently built a raised garden where I plan to grow veggies/herbs and maybe berries. I told my husband that we needed compost & top soil but he ended up purchasing top soil and bags labeled “compost & manure” which has cow and chicken manure in it. I am wondering if this is safe to use? We have equal amounts of both in it right now basically mixed together. Should we remove it all and go without the manure or add something else on top? Thanks for any help! 🙂
Tara Nolan says
Hi Peyton, Cow and chicken manure are fine (and great soil amendments) as long as they’re well-composted, which they would be in a bag. If it’s mixed with the topsoil, that is totally fine.
Cissy says
Can I layer straw mixed in the soil?
Tara Nolan says
Straw is great as a mulch and will break down so that next year when you refresh your soil, you’ll be able to add it over top!
David Rotenberg says
Hello Tara,
I’ll be using a raised bed for the first time soon, and I want to thank you and the people writing here answering a lot of my questions. What are some of the best ways to prevent earwigs and other hungry critters from eating the tender seedlings? Does copper tape work? I really do not want to make an elevated cover cover for this bed!
Many thanks in advance.
Tara Nolan says
Hi David, I’ve only used copper tape to keep slugs out. This year, I put row cover over the raised bed that has my brassicas in it. I wanted to keep the cabbage moths – and subsequent cabbage worms away. But you can’t keep the cover on if you have plants that need to be pollinated. I had a big problem this year with cucumber beetles. I was out there every morning drowning them. This article might be helpful for other pests that frequent your garden. Companion planting can help attract beneficial insects, as well. https://savvygardening.com/guide-to-vegetable-garden-pests/
Diane says
Hi Tara
I also had a problem with cucumber beetles as well as squash bugs and vine borers. They devastated my cucumbers, squash and zucchinis which I grew in my raised bed and containers. My question is can the soil in my containers be reused to plant other vegetables or should it be thrown out. I am going to amend the soil in my raised bed but with the probable presence of pests can I safely grow root vegetables where the cukes/zukes were?
Tara Nolan says
Hi Diane, Crop rotation is a good idea. You can reuse the soil, but I would amend it with compost. Planting root vegetables where your cucumbers were, if you’re rotating crops is okay. These are good companion plants, as well.
Clem says
I’m putting my raised bed (8X4) X 12inch on existing lawn, is it ok to cut the lawn and leave the cut sod as base material and then fill the bed up with the topsoil and compost? I live in Florida with all year round sun.
Tara Nolan says
Hi Clem, Absolutely! That’s a great way to build up the soil in your raised bed. I would cut the sod and turn it upside down in the raised bed before filling it.
Lynn Neal says
Hi
I am also building 2 raised beds 8ft x 4ft over existing lawn area
Is it absolutely essential to turn the sod over? I have read that its okay to put cardboard or damp newspaper over the grass then add soil? The beds are 22mm high
We have our own compost as well as 2 enormous oak trees so loads of leaves at our disposal every year
Is it okay to mix the compost and/or leaves with topsoil without adding anything else and in what order?
Glenn Adams says
Hey Tara!
Just built (2) 4’X4’X16” raised vegetable boxes. I figure I need about 32 cubic feet of soil mixture for growing. What do you suggest?
We live in Southern California…
Tara Nolan says
Hi Glenn, I generally recommend a 50-50 blend that is generously amended with compost. I also wanted to make sure that you have some tips related to your climate, so I found this article that might be helpful for you. https://www.latimes.com/lifestyle/story/2020-02-28/best-garden-potting-plant-soil-feed-loamy-peat-moss
I would also recommend adding mulch to your garden to help retain the soil moisture. http://mgorange.ucanr.edu/Soils-Fertilizers-Compost/?ds=547&reportnumber=1013&catcol=3821&categorysearch=Soil&catcol2=0&categorysearch2=
Steve Livingston says
Hello, I’m building 2 raised beds 4’x6′ and making them 30″ tall. At the bottom I’ll start with a layer of cardboard, then fill 12″ with firewood, leaves and straw. Then I’m going to use “Mel’s Mix” 1/3 Peat Moss 1/3 Vermiculite 1/3 Compost (various sources) to fill the top 15″. I have used this mix in my previous raised gardens that were 10″ deep and it seemed to work quite well. Do you see any issues with my new plan? Other than cost which I know is more, do you think Mel’s Mix is a great mix or would you ammend the recipe? I have heard Peat can make the soil acidic. I’m located in Ontario Zone 5
Tara Nolan says
Hi Steve,
The mix should work the same in your new beds. And I think it’s smart to fill the bottom a bit so you don’t have to order as much soil! For the firewood, I would stick to smaller sticks and twigs rather than logs.
Ashley Queen says
Hi Tara
Do you use Blood Bone in your soil? How much do I put in my soil?
do you use worm castings in your soil? How much do you use of that?
And mushroom manure how much do you use of that?
We have 9 raised garden beds 4 feet x 4 feet x 2 feet. I am picking up my composted horse manure in a couple days.
What do I Lay down first?
Just trying to figure out my soil blend.
Tara Nolan says
Hi Ashley, This article on soil amendments may help to figure out how much to add to your soil base. https://savvygardening.com/garden-soil-amendments/
Matt spinelli says
I want to put my raised beds on top of composit decking, , with gaps for drainage, will this be ok? I have issues with moles , don’t want the moles getting into my raised beds.
Tara Nolan says
Hi Matt,
As long as there is ample drainage, that should be fine. I’ve also seen gardeners use hardware cloth (like a chicken wire but with smaller holes) to keep moles out.
Gina says
I am intimidated by making my own blend. Could I just buy bagged raised bed soil and mix in some compost or does bagged raised bed soil lack quality?
Tara Nolan says
Hi Gina, It depends what you purchase. Look for soil that’s been formulated for veggie gardens. I would still amend that with a bit of compost. Depending on your raised bed size, you may need quite a few bags, so a soil delivery may also be a good option (look for 50/50 or triple mix blend). And I would amend that with compost, too.
Brenda says
I just built my first raised garden bed on the outside of my greenhouse i will be building then on the inside of the greenhouse as well. I have bagged raised gardenbed soil. I am going to mix in compost. My question is. Should I also add mulch to the top layer of the bed on the outside? And will the raised garden beds on the inside of the greenhouse need mulch as well?
Tara Nolan says
Outside, mulch can help the soil retain moisture in the summer when the garden tends to dry out. It also can keep weeds down. I’m not sure it’s necessary indoors.
Teri says
Do you have to change the raised bed dirt every year and if so what do you do with the old dirt can you compost it also how do you get all the dirt out of raised beds
Tara Nolan says
Hi Teri, You can leave last year’s soil in the raised bed and add fresh nutrients by top-dressing the garden with compost.
Denise Nally says
Hi there, can I use my Christmas tree branches with pine needles still on it in the bottom of my raised bed? I have our tree outside since January. It’s a Silver Tip.
Tara Nolan says
Hi Denise, I don’t have experience mulching with pine needles. I’ve read it’s possible they can acidify the soil, but i feel like they’re already partially broken down after being left out for the winter, so it should be okay to place them in the bottom and then cover with soil.
Laurie Evans says
Hello,
I am preparing new raised beds and unfortunately missed your earlier comments about using the grass cut out at the bottom of the boxes for fill. I do have some cardboard boxes and grass clippings. Can I put that down first then add the triple mix soil? Would I still need 12 inches of soil on top of that?
Tara Nolan says
Hi Laurie, yes, you can use cardboard, then grass clippings, then triple mix. And I would add some compost to the top for good measure.
Keith says
I built a planter box about 3x6x 24” deep is that to deep for a box?
Tara Nolan says
Hi Keith, As long as your garden drains well, your raised bed can be whatever height you customize it to be.
Jill says
Hi, Tara,
We killed our grass using the lasagne method and bought a couple of galvanized metal trough-style planters. The planter are one foot tall.
I like your idea of flipping the sod over to fill the bottom of the planter, but in your picture it looks like there might not be enough room for soil on top. Will it work with this much filler and whatever soil will fit on top? Or should we use less sod?
Tara Nolan says
Hi Jill, If you’re planting this spring, you could probably use a little less sod, so you have more room for soil and compost.
Larry says
Hi. Last year we bought raised beds on legs and tried to grow veggies. For media we used compost and dirt. It didn’t go very well. When we watered it seemed to drain too quick. My wife thinks maybe the seeds were not so good.
This year we’re trying compost and Miracle Grow for veggies. Any other ideas? We live in the Detroit Michigan area
Tara Nolan says
If your raised bed drains quickly I would recommend really giving it a good soak when you water. I would also recommend looking for container mixes formulated for vegetables. Often they’ll contain something that helps to retain the water. I bought an organic bag of ProMix on the weekend for some of my big pots.
Pamela Crasta says
Hi Tara,
I bought a large fabric garden bed from Amazon and want some advice on filling it on a budget. Any tips.
Tara Nolan says
Hi Pamela, If it is deep, I’ve used some of the cheap bags of black earth that are usually just used to make a garden look aesthetically pleasing and are about $2/bag. If you’ve dug up grass, you can turn the sod over and use that to fill the bottom, as well. Then make sure all the good stuff is in the top layers where the plants will grow.
Martha says
After years of in-ground veggie gardens I’m on to two standing raised beds approx 12” x 8′ x 2′. Not knowing better I loaded them with Espoma Organic Garden Soil and now see that it is not meant to be used that way by the stunted under-nourished seedlings. (I tried adding nitrogen but no change). Any suggestions to get me through this growing season and also what I should do for next growing season when the beds are empty? I’m ready to pull the seedlings, re-do the soil composition, and re-plant. Thanks so much!
Tara Nolan says
Hi Martha, Was the garden soil meant for growing vegetables in containers? You may want to add some compost to the mix. In any container of mine that needs to be refilled, I use organic soil formulated for growing vegetables. I would leave the soil you have in there for next year and top-dress it with compost and more of the aforementioned vegetable potting soil. The other thing is, do your standing raised beds have good drainage?
Stacy says
You have to be careful with compost. It’s easy to think it’s a fix all wonder amendment. My local landfill sells compost made from grass clippings & leaves.. I added it the first year and the next year. I then had a soil test and my P&K levels were off the charts high! I only used nitrogen for the next several years because there was still enough P&K. I use cow manure compost now, once every 2 years. I get it from our university. About 2″ in my raised beds. Take it easy with compost! Raised bed and potting soil is a better bet for replenishing the lost soil in raised beds.
Tara Nolan says
Hi Stacy, That’s a great point!