Best Soil For Raised Bed Vegetable Garden

[rainbowgardener]

We just had someone else writing in about clay in a raised bed: https://www.helpfulgardener.com/forum/vi ... =4&t=59038.

If I were filling a raised bed (and I have done in the past), I would never put any clay soil in it. Think of a raised bed as a giant container/ planter. As such, drainage is critical. Clay holds moisture, packs down, drives air out, essentially turns in to brick over time.

Peat moss by itself won't help, because peat moss is also very moisture holding. Peat moss WITH some inorganic component like perlite, coarse sand, crushed gravel, crushed lava rock, pumice will help. (Or there are organics that have some of the same qualities of staying in loose particles and breaking down slowly, promoting drainage, such as pine bark chips, rice hulls.)

If you are just talking about one bed, I would just dig the clay out and start over.

[zanitablythe]

I haven't had much success with a raised garden bed, and it may be because I live in such a hot climate (Texas). I ended up just planting stuff in the ground last year. However, next summer I want to try a raised garden bed again. I was just using manure in my raised garden bed, and I think I'll try using natural leaf mulch this time to give it more nutrients.

[adabc]

I will go to home depot to get some. I remember they have ,but not sure witch one is better.

[ronniemargaret]

["He will cover you with His feathers, and under His wing, you will find refuge". Psalm 91:4] I am new to the raised bed forum and have learned a lot from y'all in a short period of time. My current interest is the best soil for my raised vegetable garden beds this Spring. My virgin vegetable gardening experience was in August 2014 when I decided to begin with a Fall/Winter garden. My raised beds are 29" high and free standing (no ground underneath), 2' wide, 8' long, and 1' deep. My new best friend became the county director of the Mississippi Cooperative Extension Service. If he didn't have the answer, he could obtain it quickly. Each of my two beds contained locally prepared and packaged potting soil. The soil in bed one was premium potting soil containing some compost. Bed 2 was comprised of another type potting soil entirely and not nearly as rich. Bed preparation began with placing gardening fabric on the bottom of the cedar bed planks (which had sufficient holes for drainage), 3" of pea gravel on top of that, and then filled with the chosen soil. Next, soil samples were taken. The soil in Bed 1 was too rich while Bed 2 was too poor. My MCES mentor's solution: mix each bed half and half, and the next sampling for both boxes was perfect. I still have thriving vegetables in both boxes! This year, I am adding Bed 3, using the same formula; however, I am wanting to amend the soil with cottonseed meal fertilizer, an organic by-product of Mississippi's cotton industry. I'm curious to know if others have had success with it. Your advice is welcomed.

[Susan W]

rm Welcome! I use cotton burr, a bit different from the cotton seed. I buy it bagged at the garden center, and think source is TX. It's coarse, one reason I like it, and it enriches the soil. There seems to be an increase in worm activity where I use it.

Downside in using this, is the possible chemicals used in growing cotton. If you can find a gin that processes organic cotton, you are in luck. The gin people should be bagging that 'waste' and selling as Organic!

[imafan26]

Cotton seed meal is actually a good source of slow release nitrogen but it takes several months for it to be broken down by soil microbes so you will need to put it in early and have other sources of nitrogen that would be more readily available to support early growth. It is an ingredient in Scotts' organic lawn fertilizer.

My raised garden bed was inherited when I bought the house. It was actually not taken care of very well since the house had been a rental for 10 years. I was pretty much clay soil and weeds. It was a lot of work getting through the compacted soil and yes clay is heavy and mucky and hard to work. I learned the hard way not to work clay when it is wet, not only is it messy and heavier, it ruins soil texture. When the soil dries, there are these clods which take forever to break up. I added sand, but not enough, I needed to add 50% sand and I added about 10%. I got cement clods. I started adding Big R, and it was easier since it was a lot lighter than sand to carry and it dried quickly and I added enough of it to get the soil very soft and draining well although it held on to water for a very long time and I watered on a schedule.

I did get things to grow very well though. Although then I pretty much used miracle grow every two weeks (2 pkgs) on the whole yard. I had huge greens and the orchids were growing well and blooming, but root crops were a bust. I got a lot of tops and no roots so I gave up on growing them.

Then in February 2003 we had 42 days and nights of rain. A lot of things drowned and I lost a lot of orchids. I couldn't use the miracle grow because the plants were already drowning. As a result the following year the orchids bloomed better. Of course the year after that I paid for that because less fertilizing meant fewer blooms the year after that. But, the rest of the yard still grew fairly well without so much fertilizer.

Since I became a MG in 2009, I have been getting more organic. I switched from Big R to compost, but smaller bags, so I was adding half the amount. The soil started getting harder to work. I have since corrected and add more now. I did soil tests on all of my garden plots and the community garden, home, and herb garden are all high in phosphorus and potassium so all I really need to add is nitrogen. It simplifies fertilizing and a lot cheaper too and since the organic material holds so much water, and my water bill is outrageous, I water daily when seeds or plants are just started but once the plants are established, especially this time of the year, the garden can go a couple of days without watering just fine.

Clay is not ideal to work with, but if you add a lot of organic matter over time, it can still be a very productive garden. It has taken a lot of years, and I have made more than a few mistakes along the way, but I have learned a lot gardening and I still am learning more by challenging myself to grow new things or try different techniques. I have changed the way I fertilize, and I have a lot of nectar plants so I have reduced my reliance on chemicals for pest control. I still use slug bait and seasonally need to treat the hibiscus and roses. I plant a scavenger crop after I plant corn to use up the excess nitrogen. Hey, I even got a daikon root a foot long in my home garden. It is half the size of a daikon in my community garden, but 20 years ago I would have had 3 ft tops and no roots.

[AngelicaGray3409]

I am not an expert in this field, but I think that a soil mix which has little fertilizer and extra nutrients added is practically perfect for growing vegetables like lettuce, peas, tomatoes etc. But if you want to have a healthy garden, free of any chemicals and harmful elements, I would suggest starting your own compost bin. You can put all kinds of organic waste in there, and get great fertiliser for your soil or potting mix.

[ronniemargaret]

Thanks. I've gotten so many suggestions, for which I am appreciative.

[ronniemargaret]

Thanks, Susan W. from Memphis! I located a company in Macon, MS that sells organic cotton burr to third party retailers, so I'm in luck. I'm saving the organic cotton seed meal as a fertilizer. Love this forum! So many helpful members.

[jal_ut]

I would be tempted to use about half your native soil and add some sand and peat. Compost too if you have any.
Clay gets a bad rap most of the time. It is not really that bad for growing things if you treat it properly. One thing for sure, do not ever work it when it is too wet or you will get clumps that won't break down all season.

In the valley where I now live, I have gardened on several lots, all were quite heavy in clay. It helps to add organic matter and some sand too if possible. Those clay soils have grown some mighty fine crops for me.

Also it is well to note that the roots of our garden plants go quite deep from 3 to 5 feet. So if you are not putting a root barrier, the roots of whatever you plant will be down in the native soils anyway.

[ronniemargaret]

Thank you for the great advice. The advantages of my particular type raised vegetable bed are each bed is waist high, the cedar planks below the bed soil allows for good drainage, and there is a 3' distance between the bottom of that

[Hotelguy26]

Hi all,

New to the forum and need some help... Wanted to reply to this first instead of creating new...

I built an elevated garden bed, about 8x2.5 and about 14" deep. Looking to grow a bunch of herbs, and some vegetables (tomatoes, peppers mainly). The bed is elevated about 6" off the ground with no interaction with the native soil (I did this because our soil is horrible).

Looking for the best soil mix for herbs and vegetables. I don't really have access to any truck options or natural soil options, so I'll be going bags. More than likely Home Depot or Lowes.

I have access to the following:

Topsoil (the bagged kind)

Miracle Grow Garden Soil for Flowers & Vegetables
https://m.homedepot.com/p/Miracle-Gro-2- ... 204502220/

Premier Peat Moss
https://m.homedepot.com/p/Premier-3-cu-f ... 100626048/

Black Kow Composted Cow Manure
https://m.homedepot.com/p/Black-Kow-50-l ... 202287053/

The topsoil is obviously the cheapest, so would prefer to use that the most, but being my first garden bed, I'm open to all suggestions.

Can anyone suggest a good mix out of those?

[Hotelguy26]

Oops... I lied. I just ran a quick google search and found a company near me that has "Topsoil Plus" which is a blend of topsoil/loam and compost. 70% topsoil/loam and 30% compost (ish). They said that I could fill the entire bed with that. Is that true?

Here's the link:

https://www.harvestpower.com/topsoil-plus/

[jal_ut]

Yes, I think you would be OK filling the bed with that mix. "Topsoil Plus"
Be careful with manures. Best to add them in the fall and till it in and let it break down over winter.

[Stourme]

I have the most scientific method for checking my soils...

I go out in my garden and dig down with my bare hand...if I can dig down easily then I know I'm approaching the right texture.

I check 3" below the soil line 24hrs after watering, if it's damp... I'm probably good.

I check the look and feel of the soil, if I see broken down plant matter then I'm good.

Then when the plants are 3" tall, give or take, I'll side dress with compost or 16-16-16 fertilizer.

Grass clippings are your friend. Mulch with grass clippings and work it into your soil.

This method has never failed me

[rainbowgardener]

Grass clippings are a good source of Nitrogen for your soil. They are not very complete as a soil amendment, unlike compost which has all the macro and micro/trace nutrients and soil biology to process it. You also have to be a bit careful with grass clippings as mulch, because they can pack down and mat at which point they tend to shut out air and water and don't break down well. I like to mix grass clippings and pulled weeds (greens) with straw or wood chips, shredded paper, etc (browns) for a nutritionally complete mulch.

[Susan W]

I always chuckle when I see Grass Clippings. Am I the only one who leaves them be to nourish the lawn? I have the standard mulcher-mower, cut high, and sometimes things get thick. I just wisk any thick clippings around. Grass is green, haven't watered this season, but then we have had some rain!

[Rairdog]

I always chuckle when I see Grass Clippings. Am I the only one who leaves them be to nourish the lawn? I have the standard mulcher-mower, cut high, and sometimes things get thick. I just wisk any thick clippings around. Grass is green, haven't watered this season, but then we have had some rain!

It depends. I have 3 to 5 acres to mow depending on what neighbors help out. I can collect a bunch early on and mulch it in at the same time. Later on I just let it grow out for the bees, pollinators and Geese. The trick is to let the weeds and natives do their thing. I have never watered, fertilized or put down weed killer. The more weeds the more green that works together. Weed free green grass is an eyesore once you understand how mother nature works together. Most just fight her.

Back on topic. Search for an organic leaf compost mixed with topsoil.

[windandvane]

Grass clippings are a good source of Nitrogen for your soil. They are not very complete as a soil amendment, unlike compost which has all the macro and micro/trace nutrients and soil biology to process it. You also have to be a bit careful with grass clippings as mulch, because they can pack down and mat at which point they tend to shut out air and water and don't break down well. I like to mix grass clippings and pulled weeds (greens) with straw or wood chips, shredded paper, etc (browns) for a nutritionally complete mulch.

This might be a funny sounding question to ask, but it's nevertheless something I think about when making mulch and adding shredded brown paper - do you think the printing ink on the brown paper affects anything at all in the mulch chemically?

[imafan26]

Most newpapers now use soy based ink for the black and white pages. so are o.k. for composting as long as you avoid the colored glossy paper which has other chemicals on it. Most of the inks used today are less toxic than before and should be o.k. The amount of ink should be a very small quantity when mixed with the other browns and greens. I have used shredded computer paper in the worm bin and it has not killed the worms so I think it would be o.k. in a compost pile.

[Mr green]

Most newpapers now use soy based ink for the black and white pages. so are o.k. for composting as long as you avoid the colored glossy paper which has other chemicals on it. Most of the inks used today are less toxic than before and should be o.k. The amount of ink should be a very small quantity when mixed with the other browns and greens. I have used shredded computer paper in the worm bin and it has not killed the worms so I think it would be o.k. in a compost pile.

Well its not that simple, to legally be able to call your ink soy based it need to have only 5% soy based ink in it, the rest can be all the bad chemicals you want, and been using since the dawn of time just dilute with 5% soy ink. So it could be almost as bad as it use to be, and sadly thats the cheaper way too. Because of this I recycle all my paper with print on, it becomes new paper and all is good. But I'm quite picky with these things. If I wouldnt I think I would prefer to compost it first, then add to the garden.
Newspaper can be a good source for brown material tho specially if you live in appartments in the big city or smaller housing units with little to no garden.

[imafan26]

According to the Cornell composting site. Black and white newspaper are safe to compost.

Is newspaper safe to compost? Are the inks toxic?

" Newspaper is safe to compost, but it breaks down quite slowly because of its high lignin content. (Lignin is a substance found in the woody cell walls of plants, and it is highly resistant to decomposition).

Most newspapers today use water or soy-based inks. Although these may contain small amounts of toxic compounds, the trace levels are not of significant toxicological concern. Some caution should still be used with glossy magazines, which sometimes use heavy metal based inks to produce vivid colors."

https://compost.css.cornell.edu/faq.html

[Mr green]

Didnt find my original sources but heres a good read: https://www.triplepundit.com/2013/01/soy ... h-reality/

Also if you read on wikipedia it says: "To make soy ink, soybean oil is slightly refined and then blended with pigment, resins, and waxes. Even though soybean oil is an edible vegetable oil, soy ink is not edible or 100% biodegradable because the pigments and other additives that are mixed with the oil are the same as those used in petroleum-based inks."

And another big problem most of the soy used is GMO Soy.

So calling soy based ink a green alternative is a huge misconception in my opinion.

[imafan26]

Consider your source. Wikipedia depends on someone editing it. My source is Cornell University.

[Vanisle_BC]

The printing-ink information on the website referenced by Mr green;
https://www.triplepundit.com/2013/01/soy ... h-reality/
mostly appears to come from Gary Jones, Vice President for Environmental Health and Safety, Printing Industries of America. Probably someone unlikely to be overstating any undesirable properties of printing inks.

[Mr green]

Consider your source. Wikipedia depends on someone editing it. My source is Cornell University.

Well that wasnt my main source, you missed the link? So read again. And it doesnt make much difference, becuase what was said there is true...

[Mr green]

The printing-ink information on the website referenced by Mr green;
https://www.triplepundit.com/2013/01/soy ... h-reality/
mostly appears to come from Gary Jones, Vice President for Environmental Health and Safety, Printing Industries of America. Probably someone unlikely to be overstating any undesirable properties of printing inks.

Exactly! Good point made there.

[GardenThrive]

I go with 1/3 peat moss, 1/3 vermiculite, and 1/3 compost. It is nearly impossible to overwater with that mix, yet it retains moisture really well. I use my own compost and supplement with bagged varieties if I don't have enough. Vermiculite can be a bit expensive 20$ for a 3 cu ft bag here, but once you fill the bed once all you'll need to do the next year is just too it off with more compost.

[Carol1939]

My raised bed , planted with spinach, arugula and lettuce is showing a white mildew around plants, what can I do?

[imafan26]

If the white mildew is on the soil and not on the plants, then your soil is too heavy and wet. Let it dry out more. You can fluff the soil between the plants to help turn and air it to get rid of the surface mold. When you do your bed next time, add more drainage material, vermiculite or coarse sand and watch your watering. The surface will dry faster than the soil below. Poke a hole in the soil and if it is damp below the crust it can go a little longer. You can mulch the top to keep the top from drying out too fast. When plants are small, you don't need to water a lot, as the plants get bigger their root systems get larger and they need more water.

[Ksk]

I have raised beds with straw bales and a little top soil spread on top. I was doubtful it would work but have found it to be a tremendous boon for select edibles & flowers. Next year I will build boxes for the bales but for now they are on the ground. You need almost no soil using this method so I just bought a gab of clean garden soil.

[imafan26]

I just remembered that instead of trying to make your own mix there are two other ways to fill a bed

1. The first would be to make a lasagna bed. It would be a cheaper way to fill the bed than buying all the parts and mixing them together. Downside would be that you ideally should get it started 6 months before.
https://extension.oregonstate.edu/lane/sites/default/files/documents/lc731sheetmulchmay2015_0.pdf
2. If you have a local composting facility, they may sell a ready made mix for garden beds. If you sheet mulch part of it, you can use the garden mix for the top so you can plant right away. Or you can fill the entire bed with the nursery mix which will be ready to plant.

This is what is available to me locally. Prices are per cubic yard, if you pick it up. Delivery is very expensive ($240). Minimum is 1/2 cu. yard. This is in expensive Hawaii, you may be able to get it cheaper where you are. At $43 a cubic yard it is a lot cheaper than buying peat moss (3.8 cu ft bale = $28-$35, Compost in bags = $7 per 2 cu ft, Steer manure $5.79 per 3/4 cubic ft, Cinder $3.49 3/4 cu ft. plus fertilizer $80 for 50lbs. I have used the mix, It is good for general gardening but the cinder is not as good as sand if you are growing root crops. $37 will get a truckload of compost. However, the compost is very alkaline so, it needs to mature or have a lot of sulfur or peat moss added for acid loving plants.

[Gary350]

1. The first would be to make a lasagna bed.

About 35 years ago I made a lasagna bed with, new papers, cardboard, leaves, it was a disaster. I raked soil back, put down cardboard, news papers, leaves in several places then covered it with about 5" of soil it was late Oct. Spring I planted the garden everything was good until plants got tall and hot weather arrived. Cold winter weather did not allow any of the, cardboard, news paper or leaves to decompose roots were blocked from growing deep in the soil and tall plants fell over. Hot weather soil was too dry most plants died roots could not grow down deep where moisture was. I tried to till the cardboard, news paper, and leaves into smaller pieces but it wadded up in the tiller so I dug it up by hand then burned it later. I replanted the garden again in July 100 degree weather is a very bad time to plant a garden. Lasagna idea might work if I cut cardboard into small pieces, news paper wads a few inches apart, till dry leaves into soil instead of letting them lay there all winter like a wet carpet covered with soil. These days I burn cardboard & news papers they don't burn well there is a lot of black carbon that is good for the soil too. Tree leaves burned in a pile makes a lot of black carbon once flames are gone an fire looks like red hot charcoal I till it into the soil while it is still on fire & fire goes out quick. All that carbon makes the soil black but it is soon gone in another year or so. In fall before rain season starts I mow tree leaves it cuts them into tiny pieces and mower blows them onto the garden surface then I till them into the soil. The past 2 years we had to much rain tree leaves could not be mowed or raked.

[applestar]

Do you remember whether you wetted down each layer of the paper product and dry leaves? — Key to ensuring they decompose. Also helps to have healthy earthworm/wiggler and good fungi activity in soil so you can promote by adding them.

[SQWIB]

I know this is an old thread but wanted to share my experiences as Gary350 has.

Not all cardboard is the same, the non corrugated recycled cardboard that is gray breaks down in a few months. Pizza boxes break down rather quick as well.




If the cardboard remains wet it should break down quickly.





I use real heavy cardboard for my pathways and that takes a long time to break down.







I sometimes use cardboard to germinate my cover crop, this is the cardboard I mentioned earlier, it breaks down in a few months if it stays wet.





For my pizza boxes, I now tear up, toss in the compost bin and pour over my slimy messy kitchen scraps and some yard waste
.





I will never use shredded paper again as a mulch, it turns into an impermeable barrier.




I used to use it as a winter cover for pots, now I either cover crop or mulch.




I really don't use cardboard much in the garden, mainly due to the ants but do use it in my pathways and compost
My problem with cardboard is when I use it with mulch and its dry is the freaking ants.






As far as the soil question goes (yeah I know, Old Thread, but for folks following this and not Karl because he has posted twice in 8 years, lol) I can offer a few suggestions, whatever you do use a good portion of your native soil unless it is a contaminated soil.

If doing a lasagna method, do it in the fall for the following season not the spring and keep it moist.

Cardboard is great for a base layer if building a soil on top that is deep enough for stuff like peppers and tomatoes or using at the top and punch a hole in it to plant, that is if you do not have an ant problem!

[Vanisle_BC]

Just a quick comment on my experience with cardboard for pathways: Once rained on and starting to break up it can get treacherously slippery.

[IrinaGrant]

Firstly thank you very much for the advice to put cardboard in a compost box. I never did it. Thanks again. How long does the cardboard decompose?

[SQWIB]

Firstly thank you very much for the advice to put cardboard in a compost box. I never did it. Thanks again. How long does the cardboard decompose?

Pizza boxes will break down fairly quickly, especially if torn up and saturated, the trick is to keep it from drying out.

[IrinaGrant]

Thanks again for advice. I already put cardboard in a compost box, but cardboard from big boxes, not like from pizza. After I brought too much water. And now I am waiting.

[imafan26]

I have not used cardboard as a compost layer. I have only used it as a top layer for weed control. It has a high lignin content so depending on the thickness of the cardboard it takes a while to decompose. I don't really use it or newspaper for that matter as browns. I use them mainly for weed control. I use newspaper on the bottom of a bed after I dig it out to control weeds from coming up from below. I use several layers. Newspaper and cardboard works better as compost if it is shredded first. I put the good soil on top of the newspaper layer to plant it . On top of the good soil, I put additional layers of newspaper that I wet down and plant through that. I use the top layer as a weed barrier and mulch. For me it is the best way to control nut sedge in my garden. Eventually, the nut sedge will come back but it has been much more manageable this way. Digging out nut sedge is futile. The top layer of newspaper takes about 3 months to decompose. I tried commercial weed block but there were issues with the water not getting evenly through the fabric unless the drip irrigation is under the fabric. I still have issues with weeds sprouting around the holes in the fabric. Weeds still end up very close to the plants and are sometimes difficult to separate. Running soakers under the fabric works better if you plant in rows. I plant more intensively and usually not in rows. Weed block made of synthetic material is hard to get out of the garden when it is in pieces. I use it mainly for pathways now, but it does not stand up well to heavy traffic.

Newspaper is not the best brown to use in compost. It has a C:N ratio of about 171:1. I don't have a lot of browns. I have mostly greens. Tropical trees don't drop leaves the way temperate trees do and while I do have a few trees in my yard, only one produces branches worth composting. Palms would take years to decompose, gardenia has too many pests, plumeria and ti are not woody plants. ATTRA allows black newsprint paper in organic gardening as an allowed synthetic. ATTRA said in 2013 there was insufficient research on the toxicity of the components used in making newspaper or cardboard. Anecdotal evidence was that it was good for weed suppression and did not appear to be harmful to soil biota. As for GMO soy ink, that's a personal thing. I am not 100 percent organic, I just try to incorporate as much organics as possible. I have nothing against GMO. Considering the widespread use and that millions of people have been consuming GMO products for years. If there was any notable harm, it would have shown up by now. There are people who may be more sensitive than others to a lot of things. For some individuals, they believe the extra precautions are necessary.

As for the ants. I put out ant bait. Ants are plus minus. They harbor and nurture plants pests like aphids, mealy bugs and scale. There are some plants that attract them like gardenia and lemon grass. Tropical fire ants' bite is painful. I also have my garden patrol lizards and greenhouse frogs that eat them.

https://attra.ncat.org/can-I-use-cardbo ... anic-farm/