Growing in 4′-Wide Soil-Beds (in the dirt)

Q. I’m into setting up my fifth section of beds. Each one = 17 soil beds (18″ x 30ft). I’m challenged by land sloping both ways (main slope E-W & minor slope N-S = bed length). Anyway (going bit off issue) – I plan to plant mealies (corn) in this section. Got to thinking it may be good idea to set up 4ft wide beds (for the corn). I also, intend to convert in the future to Grow Boxes, so thought I getting the basic leveling (terracing) sorted now, could be wise in the long run. My question is – is there any fundamental “down side” to 4ft wide SOIL Beds?
Am I missing something basic & obvious?

A. Unless you can water the entire 4′ width you will need to build 2 – 18″ beds in the 4′. It will leave a very narrow “aisle” in the middle that is almost too narrow to even walk down. Weeding, etc. are more difficult that way. But if you don’t, then you have to apply water to the entire 4′, and that requires quite a bit more water. I’ve done it, and it worked alright, but it was more work. Also, the two sets of two rows are closer together than they would be in 4′ boxes, because the ridges take 3-4″ on each side. If growing vertically it’s best to plant the two rows about 8″ in from the outside edges, rather than 12″ in – again so that there is sufficient “aisle” space in the middle.

Searching for Fertilizers – Need Help

Q. I’m planning on doing a little bit of container gardening in my greenhouse this summer. I plan on using your soil-less mix as per your book “More Food From Your Garden” (out of print – I recommend The Mittleider Gardening Course)

I also bought your Micro-nutrients ( – Materials) to mix in with my fertilizer. I have searched high and low for 16-8-16, 20-10-20, 16-16-16, 15-15-15, 13-13-13, 17-17-17. I did find 20-20-20 but it is very expensive.

I also tried to find the 21-0-0 + 0-45-0 + 0-0-50 – with no luck either.

I did find a bag of 18-18-18 and was wondering if that will work. And if so, how much fertilizer mix would I need for each container that is 12″ round x 9″ deep?

My plan is to grow just cucumbers and tomatoes in the greenhouse. The rest will be grown outside in my raised (soil) beds.. Each bed is 24″ wide x 10′ long. Thank you very much for your help.

A. Any combination from 13-13-13 up to 20-20-20 will work fine. And you can make your own by buying the three nutrients separately. There are several possibilities, just look at a Farm Supply store, if the big box and nursery stores don’t have them.

The 18-18-18 is good! Just mix it with the package of Micro-Nutrients according to instructions.

For applications in small containers see my article in the FAQ section of the Foundation website under Containers or Grow-Boxes at

Your 24″-wide beds in the garden are 6″ wider than they should be for optimum planting, feeding, watering, etc. If you can’t make them 18″ wide I recommend you plant 4-6″ in from the outside edges, so you don’t waste fertilizers at least.

Mixing Fertilizer In Small Batches

Many people only have small containers in which they are trying to grow vegetables, and they only need small amounts of Pre-Plant and Weekly Feed Mixes.

Here’s how to mix Weekly Feed using one tenth of a 10 ounce Micro-Nutrient packet:

Mix 2.5 pounds of 16-16-16 or similar NPK mix with
6 ounces of Epsom Salt, and
1 ounce of Mittleider Magic Micro-Mix

For similar amounts of the simple Pre-Plant Mix:

Mix 2.5 pounds of lime (gypsum for less than 20″ of annual rainfall)
2 ounces of Epsom Salt, and
1/2 ounce of 20 Mule Team Borax

Apply Pre-Plant 1 ounce per running foot and mix with the soil before planting.

Apply Weekly Feed 1/2 ounce per runnning foot and mix with the soil before planting. Thereafter, after plants are up, feed 1/2 ounce weekly until 3 weeks before maturity.

Putting Cardboard, Linoleum, or Carpeting under the Box – What Height? – Filling with Dirt & Manure?

Q. I was thinking of using brown cardboard from fridge and stove boxes as a mulching in the bottoms of the raised beds to prevent weeds coming up into the beds, so I don’t have to dig, rake and work that soil so much prior to installing the soils the beds. Is there any reason not to do this?

I’m digging a foundation for another building and have that dirt to move, I thought it would be good in the raised beds with some additives, like peat moss, sand and manure and straw in the lower layers. etc..

How about some used linoleum, or carpeting on the bottom side of the beds? I’m making the beds 16 inches deep (so I don’t have to bend down so much as I get older.)

A. One important factor to consider in choosing whether or NOT to put ANYTHING under your Grow-Boxes is the drainage implications. If the material stops or even slows the natural drainage you may substantially hurt your crop and even kill it with a build-up of water and/or salts.

Another factor to consider before putting anything under your Grow-Boxes is that plant roots will – if the soil is available to them – travel down into the natural soil and pick up additional plant nutrients and minerals that may be valuable for humans and animals that may not be essential for healthy plant growth.

Container height only needs to be 8″. Anything more than that 1) increases the cost of building the container, 2) increases the cost of filling the container, 3) increases the cost of watering, and 4) may reduce the effectiveness of the fertilizer somewhat.

We recommend placing the boxes directly on clean soil that has been leveled. Then apply the Pre-Plant Mix, and then fill with clean inert “soil mix” materials, as well as the Weekly Feed and Pre-Plant Mixes.

The soil mix materials should NOT include dirt or manure – for several reasons:

1) Dirt is HEAVY and can push out the sides of the box.

2) Dirt often does not drain vell,

3) Dirt becomes hard and difficult to work with,

4) Dirt and manure very often contain millions of weed seeds,

5) Dirt and manure often include unwelcome bugs and/or diseases.

Jim Kennard

Micro-Nutrients Sold By the Foundation – How Much Weekly Feed Will it Make?

Q. If I grow in 4 ‘ X 4′ raised beds, each micro elements pouch – mixed in recommended ratio to make the Weekly Feed formula – will be enough for how many feedings of a 4′ x 4’ square raised bed?

A. Each Micro-Nutrient package contains two packets of 8+ ounces, which when mixed with NPK and Epsom Salt will make 23 1/2# of Weekly Feed fertilizer. Therefore the $13.95 package ends up being 47# of Weekly Feed.

The Weekly Feed is used as follows: One half (1/2) ounce per running foot of soil-bed or container between 2 rows of plants (or one row if you’re growing vertically).

Each feeding of a 4′ X 4′ box therefore requires 4 ounces (8 tablespoons), so you should have over 90 feedings of one 4′ X 4′ box.

In a 4′-wide container (we call them Grow-Boxes) you should plant small and medium-size plants in 4 rows – two near the outside edges of the box and two 12″ inside of that. This leaves almost 2′ in the middle of the box as an “aisle”.

Unless you are planting small plants like lettuce, carrots, onions, etc., you should leave the center 2′ empty, as larger plants need that space to grow and receive adequate light.

For large plants that you should grow vertically, such as indeterminate tomatoes, cucumbers, pole beans, eggplant, melons, etc. you should grow only 2 rows of plants – near the outside edges of the box.

When planting only 2 rows of plants you still feed WF at 1/2 ounce per running foot.

Since leaf lettuce only needs 3 or 4 feedings per crop, and you can probably grow at least 3 crops per growing season, you can see that one bag of fertilizer will last a long time, if you only use it for one box.

Tomatoes would need to be fed more, as ever-bearing plants should be fed until 8 weeks before the first expected frost. You also cut off the growing tips at that time, so they mature the fruit they already have, rather than wasting energy on creating new fruit that won’t mature.

Build Grow-Boxes Out of Cement Blocks?

Q. Do you have any information that would discourage using cement blocks to build the grow boxes?

A. Nothing serious. They take up aisle space, cost more than wood, and are more work to install because you need to secure each block – either by mortoring them together or with a Rebar stake.

On the positive side, they look good and will last indefinitely without being subject to deterioration that is common to wooden boxes.

Jim Kennard

Non-Standard Size Grow-Box – Filling and Fertilizing

Q. I have built 2- 4’X4′ grow boxes that are 10″ deep. I purchased
on the Food for Everyone website 2 8 oz.packages of the micronutients. For 1 package I plan to mix my weekly feed ( w/ 3 lbs epsom salts and 1- 20lb. bag of 16-16-16.

My plan was to use the other micronutrient package for the preplant mix (mixing with gypsom,epsom and Borax)

Question #1- For the preplant mix, how much gypsom, epsom salts and Borax should I mix in to place in each each box? I am not
mathematically inclined, so any help on figuring out the measurements is VERY appreciated.

Question #2- Am I okay to use the micronutrients package for the
preplant mix, or is that just for weekly feed?

Question #3 I plan on using 1/2 Blowsand and 1/2 Peatmoss as my filler- how much should I buy to fill both boxes?

A. Ten inch-deep boxes are fine. However, they use more materials than necessary and don’t grow any better crops than 8″ boxes. We recommend boxes that are 8″ deep (actually 7 1/2″ is the standard size you will get at the lumber store).

Do NOT use the micro-nutrients in your Pre-Plant mix. It is unnecessary, wasteful, and might even be bad for the plants. The Micro’s are only to be used to create the Weekly Feed Mix.

Remember in mixing the Pre-Plant to use 80 parts lime or gypsum, 4 parts magnesium sulfate, and 1 part 20 Mule Team Borax.

The amount of Pre-Plant you need to use in a 4′-long X 4′ wide box is 2 ounces per running foot (1 ounce per running foot in an 18″-wide box).

1. On the soil underneath the box spread 8 ounces (that’s 2 ounces per running foot).

2. Mix another 8 ounces of Pre-Plant with the soil mix at the same time as or immediately after you fill the box and before you plant. And at the same time mix 4 ounces of Weekly Feed into the soil mix.

You will need 13.33 cubic feet of material in total. You will have a better mix if you use less sand, and add some Perlite. I recommend you use 50% peat moss (or sawdust – preferred) 15% Perlite, and 35% sand.

Recommended widths for Grow-Boxes and Soil-Beds

Q. In many of the books the Grow-Box width is very different. What is the latest recommendation on the ideal size of Grow-Box width? 1 foot? 18 inches? 4 feet?

A. The need for the question illustrates the fact that Dr. Jacob Mittleider experimented with the different aspects of his growing procedures throughout the many years of his worldwide humanitarian work. He tested and measured the results of everything he did, to determine the very best way to do things.

In 1975, when his second book More Food From Your Garden (later re-printed as Grow-Box Gardens)came out, Jacob was advocating Grow-Boxes of 5′ width, usually with plants growing in rows across the width of the box. He taught and demonstrated growing in that size box for a number of years – always with great success. And even today there are thousands of growers – even commercial growers – who swear by their 5’boxes.

He also sometimes grew in boxes that were only 1′ wide during those years. And some of the boxes shown in the book Let’s Grow Tomatoes are 1′ wide.

Over the years, however, after much experimenting with different
sizes, Jacob settled on a height of 8″ and widths of 18″ and 4′ as
being ideal for growing vegetables, and those are the sizes we teach, demonstrate, and advocate today.

Eighteen inch-wide boxes or beds are excellent for growing one row, for large and climbing plants, or two rows for other vegetable crops, and usually work best in the family garden situation.

Four foot-wide boxes or beds allow for even more concentrated growing of crops for serious growers. However, when using 4′-wide boxes or beds more careful plant spacing and pruning are necessary to assure plants have adequate light throughout the growing season.

Large crops should only be planted in two rows down the length of the box or bed and on the outside edges. And smaller crops are also planted lengthwise – in four rows one foot apart, starting at the outside edges. This gives only a 2′-wide “aisle” in the center, rather than the 3 1/2′-wide aisle we normally recommend.

It’s that narrow center aisle that saves a foot and a half of space, but it’s also what makes proper plant spacing and more diligent and careful pruning so important.

I recommend you use narrow boxes or beds when starting out, and then perhaps work with some of 4′ width as you gain experience in caring for a high-yield intensive garden.

I have downloaded some pictures of the Model garden we created
and grew in Popayan, Colombia in the Pictures section of the free group, to show you some
4′-wide “double beds” in action.

Soil-Mix and Fertilizers to Use for Raised Beds

Q.  I’ve read about using manure, compost and peat for planting medium in a square foot garden. What is the ratio one to the other for a veggie garden. I would like to use organic fertilizers also. Do I need to buy top-soil to mix with the other stuff too? I’m thinking of using 2″x12″ for the frame.

A. I highly recommend you consider carefully before using manure and compost in your raised-bed garden. It is believed that more than 90% of the composted materials available to the family gardener have NOT been sterilized in the composting process.

To be sure you have clean materials you would have to know that they had been composted at 140 degrees for 3 weeks. That’s what it takes to produce compost using aerobic processes, and that’s the only sure way I know of to remove diseases, weed seeds, and bugs.

I suggest you use a mix of three ingredients, including sand (30%) and any of these: sawdust, perlite, peat moss, or vermiculite – in that order of preference. Do not use top soil in the mix, as that is heavy, difficult to work with, and also often contains the 3 “badies”.

In addition to the great potential for problems with the above, using manure and compost leave you guessing as to what you are giving your plants by way of nutrition.

And the third reason you need to be careful is that using manure and compost can often lead to a salinity problem with your tiny plants. Plants need small amounts of 13 mineral nutrients over the entire course of their growing cycle, rather than one large application of fertilizer salts (which manure and compost have) at one time.

We teach and demonstrate the best growing principles and procedures, which allow us to promise the world “a great garden in any soil, in any climate” with no record of a successful challenge in the past 40+ years.

We use small measured amounts of natural mineral nutrients to give plants exactly what they need for sustained healthy growth, and we teach you exactly how to to the same.

And you only need frames 8″ high, rather than 12″‘s. You’ll save on materials, fertilizers, water, and work, and your plants will bless you.

I invite you to visit the Foundation’s website at, specifically the FAQ section, where you’ll find many worthwhile short articles on growing organically. And the Learn section will teach you everything you need to know to have a highly successful garden – without buying anything from us.

Best wishes,

Jim Kennard, President
Food For Everyone Foundation
“Teaching the world to grow food one family at a time.” –