How to turn garden soil into soil appropriate for garden beds?

Hello everyone,
I am currently making some raised garden beds (and trying to do it as cheap as possible). As such I already happened to have several bags of Sta-green flower/vegetable soil but it specifically says for in ground use. Are there amendments I can buy that would essentially turn it into soil for raised beds?

How is that not in-ground use? Raised beds are soil surrounded by supporting wood planks, usually. Some want soil with no weed seeds, some use existing soil and build up the beds with soil in the walkways. The rich folks I work for often use a manufactured product made by mixing sand with composted yard waste and woodchips- it’s a bit of overkill as it is about the equivalent of a better draining muck soil- productivity doesn’t rely on soils with more than 6% organic matter.

I use something called the French intensive gardening method which involves no frame and a little shoveling back of soil every season. There is a theory that this duplicates the loose soil created by landslides where plants tend to grow very vigorously compared to same species in nearby stable soil.

It’s been my method for about a half century and I always use existing soil, improving it over time with compost and mulch. Serious gardeners are often blown away by the productivity I get, but that is probably the result of a variety of things.

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I would buy garden soil and mix it in. It is all organic material thus a good thing in raised beds. . Just using that soil would not be the best mix. All my old potting soil goes in my raised beds. It helps add organic material.

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i try and mix a few different types of bagged soil. garden soil/ topsoil/ compost and composted manure with some rock dust and old potting soil. has worked for me for 7 yrs now. i recycle everything i can. the more variety you mix in there the better. a little blood meal adds more N.


I do add top soil too as all that good stuff is quite a rich blend I also throw yard waste in the bottom of any is around.


I would just backfill with any kind of soil and plant a cover crop. It would also be wise to plant an edible perennial in there to keep the biological gains over winter. I use chicory for that (specifically, forage chicory I bought from Urban Farmer), so I get the fertility gains, the deep taproots, and much chicory every year without any work.


How big are the raised beds you are filling? The actual question is how many cubic feet of fill you need?

My usual fill is one part horse manure compost, one part dirt, one part vermiculite, one part peat moss or coconut coir for the last one if peat moss bothers you. That creates an extremely fluffy soil to grow just about anything.

Power tip: if there are horses in a 50 mile radius of you, it means that there are people desperate to give you their manure or even cured compost from a huge pile. A single horse craps about 35 pounds of manure a day. Times 365, times say 20 horses for a small outfit, that is, I kid you not, around 127 tons of horse manure a year. At first you may find an outfit that charges you a token amount (mostly to cover the time to deal with you) but if you persist you can find the one giving it for free. Keeping things simple well aged horse compost and dirt is all you need.


Agree fully with Don, I am lucky to live near a horse barn where manure and waste straw and alfalfa hay are always available and free to take. So each fall I create several compost beds large enough to till with my tiller. Several year ago I bought some Canadian and some European crawlers. These and the red wrigglers do wonders for the compost piles and the garden while keeping me well supplied with fish bait. To the compost goes all kitchen waste and my weeding waste is buried deep enough that typically I never see them again. Several times a year I bring in fresh river sand to complement the compost piles providing the worms plenty of grit to convert wastes to nutrients. I use about a third of the pile each year to plant potatoes. Then on top of the remainder we plant tomatoes and zucchini and cucumbers. If you can obtain these natural ingredients, you should never need to buy the other products mentioned.
Kent, wa

I used to scavenge for the free composted stable waste often available in operations that don’t have to immediately cart if off, but it is variable and generally loaded with noxious seeds- which is fine for me, but not everyone.

I’m not sure why you would prefer to use a product like vermiculite to make a garden soil than just using sand if it is needed to increase drainage. The stuff is expensive an unnecessary to make a superior soil. The peat is questionable to me as well. Very light soil is necessary for creating adequate drainage in a pot, but peat moss rapidly breaks down in a soil to a texture not superior to your composted stable waste. In a bog, it is its high acidity and lack of oxygen that keeps it in its fluffy undigested form.

Not that your recipe wouldn’t work great for growing vegetables, but it sounds like something for container growing and you can get equal results without wasting so much money, not to mention the labor of mixing the peat moss in with the rest of it. Has to be premoistened ant the process is pretty laborious for me.

I did say at the end that dirt and compost would work just fine.

I have sandy soils. Vermiculite aids with water and nutrient retention.

I use peat moss because I have access to a mountain of decades old horse manure compost that it is as dense as dirt. Peat moss fluffs up the mix, improves aeration, and water retention. If you need to add acidity to your soil it will do that; most fruits like things in the mildly acidic side of things.

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Once when I was going to teach a class at the NYC Botanical Gardens I took a look at a vegetable garden that was being created there and saw that instead of making the essential modifications of the native soil they had replaced it with an artificial mixture that included a lot of peat moss and perlite.

Maybe because I’ve been pulling my living out of the soil (real soil) one way or another my whole life, I reacted to this as though it was cheating- this isn’t what “real gardeners” do, this is like someone claiming to be a good cook when serving take-out on nice plates.

My reaction to your suggestions probably isn’t fair, but I do try to inspire people go beyond recipe gardening where they follow directions without understanding the why. There is a tendency for passionate hobbyists to look for “magical” ingredients that will quickly transform their labor into great results.

I suppose following recipes is the shortcut to this, but my instinct is to break things down to how and why and let people learn to make educated choices. To me, vermiculite, perlite and peat moss are ingredients to make potting soil or for hydroponic production for lack of more economic choices that could take you to the same place.

That’s fair, we all have our views.

This is my problem: from a plant stand point, I have no soil. I live in the Matanuska valley where for miles on end it is nothing but glacial wash; you peel the few inches of top soil they put down for the lawn and it is 50%+ rocks, the rest sand. I had a 2 story garage/workshop built last year. The soil is so devoid of organic matter to the point that all they needed to do was scrape the surface and level before pouring the slab. My driveway is not paved; no matter how much it rains it remains a solid surface.

The nutritional deficiency is abysmal. Anything that is water soluble is pretty much gone. Nobody needs a soil test to know that there is no boron in the soil so you can safely start by amending that. Just removing the rocks leaves me with over 50% less ‘soil’ volume that I started with.

The soil I mix starts at the very least 50% of the sand that was there plus 50% well aged compost. I have no need for perlite, but I can use the water retention of vermiculite and the slight acidifying action of peat moss. After that is year after year of compost and green mulch; I just finished mixing what was left of last year’s top mulch around the trees with a fresh load of compost, which then gets topped with fresh green mulch for water retention.


it amazes me anything grows in AK. you would probably love my heavy clay soil .

Actually what the soil may lack is more than made up with 20 hours of sun in the summer. If it is a sun-loving crop, it can go crazy here:

I’m into fruits and berries. Most people don’t realize that there are apples that don’t mind cold snaps in the -50f range. Not that it gets that cold where I am, I have seen -20f and that’s cold enough for me.


I have installed 100’s of orchards in every type of soil imaginable or lack thereof. I had one orchard where the owner told me he brought in top soil by the truckload so not to worry about the soil. It turned out to be blue clay almost pure enough to make pots out of. He was paying nothing for these truck loads because it was from a development project where they were flattening a hill- it was subsoil

I have also had situations where there is a rich layer of a few inches of almost pure humus over solid rock and soils that you could use for a child’s sand box. In none of these soils was vermiculite needed, but in the clay I did use some perlite for peach trees, the sand and stable waste compost just wasn’t cutting if for them although all other species were thriving in the mix I made with the existing clay and massive amounts of sand and composted stable waste. The peach trees I originally planted survived but refuse to thrive so I replanted after adding enough perlite to make their raised beds almost seem like potting soil… but that was blue clay.

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we get max 16hrs of light in our summers so i know about quick growth but you guys have real turbo charged summers! bet a pile of compost is worth its weight in gold there! its hard to make here also with our cold winters. need to be close to one of those musk ox farms.

“Need” can be a fuzzy thing. For example I don’t think my soil has any need for perlite. Vermiculite on the other hand, it just can put to a good use.

For the most part my goal is to bring the forest to my trees. Year after year I dump green mulch and compost expanding the circle around the trunk where instead of grass there is a thick carpet of decomposing humus. It works so well that the 4 inches or so of green mulch I’m laying down now will be just about gone by the late fall, when I’ll have to add more for the winter cover.

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what are you using for green mulch? comfrey?

Mostly cottonwood and aspen. Stupid weed-like trees that refuse to die and next time you look they are 8’ tall.

Green mulch goes to the trees, brown mulch goes to fill the area behind my property.

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Here in NY, mulch is great for establishing trees but over time can create a very strong vegetative response in bearing trees and I suspect reduce to brix content of fruit. When trees are establishing you want vigorous growth but once they are in full productivity you only want moderate growth and a thick layer of humus can make it hard to dial down vigor in a climate where it rains through the growing season.

I think of it as bringing the forest to the trees also. Forest soils are a tree-made parfait of distinctive layers- the top 3 being black humus topped by nearly composted leaf and other litter and a mostly leaf mulch on top. Root activity may be concentrated in the humus layer in spring but on years where there isn’t surplus rain, by summer the activity shifts downward as the top dries out and the lower levels warm up.

Recreating that with isolated trees certainly does help them establish.