Baxter,

Compost and topsoil sounds good if the "topsoil" is true native topsoil and not something you buy in a bag that was mined from river muck or manufactured from God-knows-what. If by "topsoil," the formulas mean "the material you obtain from the top 12-inch or so layer of earth native to your environs" and which has all the humus and soil particles typically found in such true topsoil, then mixing it with compost renders a good growing medium.

Right now, I'm growing tomatoes in two beds. One is about 3 parts silt loam topsoil and 1 part compost covered with bark chip mulch. The other is about one part clay loam topsoil and three parts compost covered with grass clippings and leaf mulch (it started out as kind of a "lasagna" bed).

The compost in both beds is rather rough in that it was about one half bark fines and tree chips, and one half horse manure and bedding. Both beds yield good tomato plants.

I think composted organic material (no animal flesh) is the best thing in the world for adding to native soil to create tomato beds. Just my opinion. But I know for a fact it improves drainage and improves nutrient delivery to the roots of tomato plants.

That last formula in your post, 4 parts compost to 1 part manure ... and I'm assuming the manure is well rotted ... simply equals 100% compost in my book. Remember the old joke about "what's that white stuff on top of chicken dookie?" Yep ... just some more chicken plop! :::smile:::

Click on the blue or pink hyperlink to go to another discussion here at Garden Web regarding your questions: Tilling or Turning

I wouldn't have a problem with any of the ratios you list except maybe the last one. It all depends on the quality of the soil and the compost.

But there is no absolute right mix as long as it is a MIX and that mix includes lots of good compost. ;)

Dave

here is list of the great tomato soil mixes.
mix 1:

5 parts sandy loam top soil,
1 part sand
1 part organic forest humus,
1 part peat moss,
1 dry manure,
1 part perlite
1 vermiculite

mix 2:
5 part sandy loam top soil,
1 part sand
1 part organic forest humus,
1 part Canadian sphagnum peat moss,
1 part decomposed manure,
1 part perlite
1 part ground bark.

Matrixgardener,

That sounds like Al's container mix over on the container forum or close to it. But I think Al uses more pine bark phines(?).

There is a huge thread on that list that is a very good read. I maybe wrong, but isn't a raise bed pretty much a container? Seems like you could use Al's mix in one. Let me go find that mix....

Bill S

Here it is from the container forum:

I'll give two recipes. I usually make big batches.

3 parts pine bark fines
1 part sphagnum peat (not reed or sedge peat)
1-2 parts perlite
garden lime
controlled release fertilizer
micro-nutrient powder (substitute: small amount of good, composted manure

Big batch:

3 cu ft pine bark fines (1 big bag)
5 gallons peat
5 gallons perlite
1 cup lime (you can add more to small portion if needed)
2 cups CRF
1/2 cup micro-nutrient powder or 1 gal composted manure

Small batch:

3 gallons pine bark
1/2 gallon peat
1/2 gallon perlite
handful lime (careful)
1/4 cup CRF
1 tsp micro-nutrient powder or a dash of manure ;o)

Perfectly good tomato growing soil for raised beds (note the original post is regarding raised beds, not containers) can be made without expensive, store-bought materials such as vermiculite, perlite, Canadian spagnum moss and other "soilless" media.

But since Baxter's original post only mentions one 6-foot by 4-foot raised bed, and that would require only 24 cubic feet of material to acquire a good 12-inch deep feeder root zone, I suppose it wouldn't cost too much to buy a cubic yard of fancy schmancy amendments for such a small project.

However, if I were wanting to do raised beds for a dozen or two tomato plants, I sure wouldn't build it out of 40-pound bags and cubic yard bales when there's more economical materials at hand.

The right answer is probably that there is no "correct" answer. There are a number of ways to do this, all of them work.
My sister's answer was to call up the lady with the dump truck at her neighborhood garden center (listed in classified section of her local paper under 'topsoil') and have her dump a load in the box. Then lime, work in some dried cow manure and call it a garden.
I've constructed a bed out of newspaper, woodshavings, composted cow manure and some rather thin topsoil. And lime.
Or, used a bale or two of peat moss, lime and bagged soil and then 10-10-10.
It all works and it will all grow tomatoes.
Suggest you check out local sources first. But be aware that 'topsoil' can vary enormously. Some from a box store turned out be silt and pretty worthless. The stuff my oil company provided after they spilled oil on a bed and DEC excavated it, was contaminated with weeds I'm still fighting years later. What my sister got was skimmed off of clear cut pine forest and is pretty good, though acid.
Around here it's mostly taken from fields being cleared for development. First they cut the trees and brush, then they remove the top soil and sell it and then put up houses and sell to people who have to buy the topsoil to grow anything.

I haven't found a state yet that has a legal definition for commercially vended topsoil. It's truly a case of "buyer beware" and in most cases you aren't gonna get anything remotely related to natural topsoil from a native source. What you're gonna get is likely river bottom dirt if your lucky, or some muck dredged out of a silted in lake, or sludge from a sewer treatment plant mixed with sawdust, powerline wood chips and fill dirt.

Most likely you will get whatever is available to the vendor, and in some cases the exact same material will be sold as "topsoil," "garden soil," "fill dirt," or whatever other creative marketing moniker the vendor decides to write on his advertisement or invoice. I've even seen cases where the same material was sold en masse to one developer as "fill dirt" for 9 bucks a cubic yard, and then delivered to a sucker homeowner as "topsoil" for "35 dollars a scoop."

If you want "topsoil" that is best matched to the soil native to your property, the best thing to do would be build it yourself by first getting a really accurate soil analysis to see what your existing soil is deficient in, then adding fully decomposed organic material (compost) to your soil at a minimum ratio of 9 parts soil to 1 part compost. That's just for starters. A higher ratio of compost if you have it would be better.

Mix the compost with the soil very thoroughly, so the silt and clay particles are bonded well with the organic particles, then charge the finished product with fertilizer in whatever N-P-K percentages/poundage your extension agent or soil scientist recommends BASED ON THE SOIL ANALYSIS.

If you don't have a compost heap but want to continue building your homemade topsoil cheeply, mulch your beds when and where you can with grass clippings and chopped fallen leaves in thin layers ... like maybe a few inches each time ... and let the mulch dry out and oxidize down before adding another layer. That should avoid burning the plants or their roots which could happen if the still undecomposed mulch is too thick and heats up. Keep the green mulch from touching the plants. Turn it into the soil at the end of the season after you clear your garden.

Fresh tree leaves have just about the right carbon/nitrogen ratio (30:1) to decompose without robbing the underlying soil of nitrogen. Grass clippins are a bit off at 12:1, but you can add some dry leaves (40:1) or oat straw (45:1) to bring grass clippings up to a better balance.

Keep an eye on your plants and they'll tell you if your N-P-K is getting outta wack. Re-test your soil every 3 - 5 years. If you want to build homemade topsoil rather than get ripped off by some slick operator, remember ... compost is your friend and decomposed organic matter from vegetative sources is what true native topsoil is all about.

Consider a raised bed a "container." I wouldn't use any topsoil in a container... trust me...

Thanks for all of the suggestions. I Ithink I am going to start with a product called Leafgro -- which is compost made locally from grass and leaves. I'm not certain where I would get top spoil tat would be worth adding. The soil around here is basically clay. I have a worm bin, so I will be adding worm castings as well.

Baxter, I use something similar from a local town composting facility, but they don't bag & market it though you do have to pay for it, but it's cheaper than buying other ingredients. Grass & leaves probably are the main ingredients here.

I recommended not to use topsoil because I have all raised beds and containers and have done that, been there. I asked for a topsoil & cmpost blend and was disappointed, plus it compacted too easily, and if you want to do it right the first time, use the best you can from the start.

If I redo my raised beds, I would use a similar mix to what I use in my containers:

about 40% compost
about 50% ProMix BX
about 10% composted cow manure 1-1-1.

You can make your own soilless mix similar to ProMix but it isn't fun, and may be difficult getting the peat wet, and ProMix already has a wetting agent in it. Below are different formulas of ProMix to get an idea of the ingredient proportions...

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Keep in mind that many of the formulas above do well all by themselves if you add fertilizer (PGX is actually for seedstarting and plugs, stay away from any that have "fine" listed) but you can cut your costs by adding more compost if it's cheaper than the ProMix or whatever other soilless mix you use--depending on location, ProMix may not be available but you may have Fafard, Sunshine, Metro Mix, etc. If you make your own soilless mix, shoot for something with similar percentages of peat as in the chart--anywhere from 50-75% is a good amount of peat if you use perlite & vermiculite too, plus dolomitic lime, providing you use compost for the balance (or near balance) of your bed.

Hope this helps.

Mark

I am a firm believer (from experience with raised beds) in using lots of composted leaves and composted horse or cow manure, along with some lime to adjust the pH. Mix into sandy loam soil, along with 5-10-10 fertilizer. Use Miracle Grow for watering the plants. I use about 3 inches of pine bark mulch or grass clippings on top of this after setting out the plants. HARD TO BEAT.

In a raised bed, 50/50 sand/compost. An organic commercial blend.
I have 13' tomaotoes this year. I used no fertilzers.
the raised be is on a slope for good drainage.

I have an in the grown tomotoe topping 10' in the same commercial soil.

I'm in zone seven. It's rare to see a 7' plant arround here. Heck even 5 is considered big.

To break up clay, check out gypsum and jersey green sand.

Okay, we're wandering onto shaky ground now. Beware gross generalizations about amending soil ... especially with so few details ... because following such advice can make soil problems WORSE!

For example, whenever someone says to add "sand" to soil to loosen the texture, just what kind of "sand" are they recommending ... and just what kind of soil is the sand being added to? Course, sharp sand is different from fine grained sand, and performs differently in various soils. Besides, adding fine sand to heavy clay soil renders something akin to concrete. If you consult a soils classification pyramid, you will find it would take about 50% sand to change a heavy clay soil to anything approaching a "clay loam" and then only if the original soil had some silt content.

The recommendation to add gypsum to soil may be even more reckless. Gypsum is a mineral product similar to lime. But lime is calcium carbonate and gypsum is calcium sulfate. So, where lime RAISES soil pH, gypsum LOWERS soil pH due to it's sulfate component.

Gypsum has been used effectively where soils are salty, like where oil wells have spilled out saline water onto farmland. And since the sulfate in gypsum slightly acidifies soil, it could be used on alkaline soils out west.

Before you add gypsum ... or ANY pH changing products to your soil for that matter ... GET A SOIL TEST and follow the soil scientist or extension agent's advice as to pounds per acre!!! Changing the pH of your soil changes the availability of minerals in the soil and your plants' ability to utilize various nutrients.

For example, there are forms of chlorosis that look identical on the leaf, but are caused by deficiencies of different minerals caused alternately by too high or too low pH of your soil. Don't change the pH unless you are doing so based on science ... NOT FOLKLORE.

I'm not sure what "jersey green sand" is ... except that it contains potassium, phosphorus, iron, magnesium, calcium and other trace minerals ... and sounds EXPENSIVE! You can get P, K, Fe, Mg, C and other trace minerals in less expensive forms of common fertilizers (chemical and organic) than those fancy schmancy green and white bags with the budget busting price stickers.

To sum it up bluntly, I would beware of any seat-of-the-pants advice that is grossly general in nature, given without regard to locations and soil types, with testimonials implying that fully healthy, monster tomato plants can be grown in an unspecified source "commercial mix" of 50/50 "compost and sand" WITHOUT any additional nutrient source. Plain sand has little or no nutrient value, and "compost" from a "commercial" source may or may not hold sufficient nutrients depending on the source materials from which the compost was decomposed.

Actually, gypsum doesn't lower pH.

>>"Actually, gypsum doesn't lower pH."Depends.

If you have sodic or near sodic soils, the gypsum will, through chemical reaction with the sodiums, result in decreasing the pH of the soils.

Also, since gypsum can increase the uptake of available calcium in soils, the increased calcium uptake by roots when gypsum is applied can decrease the pH of the rhizosphere adjacent to plant roots.

Source Note: paragraph reading: "Decreases pH of sodic soils: The sodic soils are characterised by the high soil pH (>8.5). Gypsum lowers the high pH of sodic soils or near sodic soils to 7.5 to 7.8. These values are in the range of acceptability for growth of most crop plants. Increased calcium uptake by roots when gypsum is applied can decrease the pH of the rhizosphere."

I'm not advocating or condemning the use of gypsum when the application is appropriate and a part of a well planned program including soils tests and specific application rates based on soils needs. I thought I made that clear in a previous post.

What I object to is out-of-hand recommendations or the implication that gypsum ... or any product ... is beneficial to use by just going to a nursery center, purchasing a ten dollar bag of powder, and tossing it into the garden.

Korney,

I re-read the link I posted and thought to look into it a bit further. I had been told by my county extension agent that gypsum was useful in saline soil reclamation associated with oil wells, and on alkaline soils out west ... and had not done any extensive research on my own.

Okay ... so I found this link too: Two Year Gypsum Study . While it's only based on two years of gypsum applications, it does raise some questions, and I will do some additional research to resolve my apprehensions.

Meanwhile, I know there's a few giant pumpkin growers adding gypsum, applying milk, and other "calcium" treatments to stave off blossom end rot and building wall strength. But I'm still a little bothered by wholesale applications of soil amendments without a scientifically proven need based on soils tests.

Regards.

I'm not sure how To break up clay, check out gypsum and jersey green sand turned into out-of-hand recommendations or the implication that gypsum ... or any product ... is beneficial to use by just going to a nursery center, purchasing a ten dollar bag of powder, and tossing it into the garden. and wholesale applications of soil amendments without a scientifically proven need based on soils tests

I refer you to item 3 on this web page: http://dictionary.reference.com/browse/check%20out

Please don't put words in my mouth.

Adding jersey greensand: Depending upon your area, can be purchased for about the same price or cheaper than other organic fertilizers. I mentioned it because supposedly it has clay busting properties like gypsum.

If you want I can explain in detail why my orignal post is exactly as it is rather than the seat of the pants I am being accused of but, that would detract from the purpose of this thread.

While researching gypsum and green sand, I found this quote from U.S. Gypsum Corp's brochures that caution gypsum is not a complete or permanent fix in heavy soils:

"...to achieve greater depth and faster action, gypsum, in conjunction with organic material, must be cultivated into the soil. Gypsum does not permanently loosen clay soil (rather) it keeps soil conditioned only as long as enough soluble calcium is available to keep the clay Âflocculated. For more permanent loosening, organic matter must be added along with the gypsum."

There's not as much information online about Jersey green sand as there is about gypsum, but I'm running across some interesting stuff.

Best crop of tomatoes I have ever had was my 1st year in a raised bed:
1/3 mushroom compost
1/3 sharp sand
1/3 native clay

I have seen stong production using Synagro compost in raised gardens, but sludge seems to worry many gardeners.

Gary