First Fertilizer Application – Pre-Plant & Weekly Feed

Q.  In the Mittleider Gardening Course we are instructed to spread lime on the bottom of the grow box, and again on the top of the grow box (mixed into the soil mix).  That is easy to understand.  On page 107 the instructions to make Pre-Plant fertilizer include another 5 pounds of lime or gypsum.  Is this correct?  Are we supposed to apply three applications of lime or gypsum, or does this formula take the place of the lime or gypsum spread at the bottom and at the top?  Very confusing.

A.  Let’s try and be very clear about this, so that everyone understands the whole story.

If you need to make your own Pre-Plant Mix you can make a simple batch by following the instructions  on page 107 of the Gardening  Course. The amounts described in the example are 5# of lime, 4 ounces magnesium sulfate, and 1 ounce boron. This amounts to 80 parts lime, 4 parts magnesium sulfate (Epsom Salt), and 1 part boron, and there is nothing magic, or even important about the size of 5#, etc. You can mix any size batch you want, just by using those ratios.

After making or buying your Pre-Plant mix you then need to apply it to your Grow-Boxes or Grow-Beds. If you are growing in containers, which we call Grow-Boxes, the very first time – even before you fill the box with soil mix – you should apply the Pre-Plant Mix to the surface of the soil below the box.

Apply 4# to a 4′ X 30′ box, or 2# to an 18″ 30′-long box.

After filling your Grow-Box with soil medium you apply the same amount of Pre-Plant mix to the surface of the soil as you applied to the soil beneath the box. Then you apply 1/2 that amount of Weekly Feed to the surface of the soil medium. Then you mix everything thoroughly into the soil medium.

Thereafter, you will only give one application of the Pre-Plant mix – mixed into the soil medium, along with Weekly Feed – before planting each crop in that Grow-Box.

If you are growing in Grow-Beds (in native soil), you only apply Pre-Plant one time for each crop – again, along with the first application of Weekly Feed – and mix them thoroughly into the soil.

If this still seems confusing, please read it two or three times, until you’re sure it makes sense. It is very important that everyone apply Pre-Plant to their garden before planting each crop, because Dr. Mittleider determined from his world-wide experience that calcium (lime or gypsum) is the FOUNDATION of a good feeding program.

Soil Mix & Ratios – Fertilizers to use and How Much

Q.   I think what I need to know is, 1) what do I put in the soil mix and 2)  proportions, as well as 3) what fertilizer to use and 4) proportions to mix in soil, plus 5) how much to feed weekly. 
A.  The fertilizer formula is on the website in the Learn section, under Fertilizers.  When it’s mixed accurately, using the materials we recommend, the NPK ratio is 13-8-13 in the finished Weekly Feed Mix.
For small gardens we suggest people use 16-16-16, if they can’t get the individual ingredients, and add the Micro-nutrients from the Foundation, along with Epsom Salt, in the prescribed amounts.  If 16-16-16 is not available we recommend 13-13-13, and in extremitties we suggest 10-10-10.
You must NOT forget to include the Pre-Plant mix in your preparations.  Buy lime, magnesium sulfate, and boron, and mix them in the ratio of 80-4-1.  Then apply as prescribed, along with Weekly Feed, and mix into the soil before planting.
If you’re growing in containers we recommend clean materials, such as sawdust, peat moss, perlite, etc. mixed in any combination with sand.  The sand should be between 25 and 35% by volume.  Other materials you can use with the sand include ground pine needles, coconut husks, or rice hulls.  We do NOT recommend compost, manure, or DIRT.
If you are growing in a 18″-wide soil-bed or Grow-Box, as we teach, demonstrate, and recommend, you should use one ounce per running foot of Pre-Plant mix one time, and 1/2 ounce of Weekly Feed per running foot each week until 3 weeks before harvest for single crop plants, and until 8 weeks before you expect to end your harvest for everbearing crops.
Those amounts translate to 2/3rds of an ounce (4 teaspoons) of Pre-Plant and 1/3rd of an ounce (2 teaspoons) of Weekly Feed per cubic foot of soil.

Undissolved Fertilizers, Placement, Frequency, Amounts, Avoiding Damage to Plants

Q.  I applied the dry fertilizer/micro nutrient mix by hand.  I did notice that there
seems to always be undissolved fertilizer, even after several waterings. This didn’t seem to bother the more mature plants, but I’m wondering if it could “burn” the younger plants, and also wondering if I should modify the fertilizer routine for the younger plants.

A.  The Weekly Feed Mix is about 45% actual mineral salts, and the other 55% of the material is NOT fertilizer, but just filler material. The only time you would not see residue is if you were to purchase the expensive totally water-soluble fertilizers that the hydroponic growers use in the greenhouse.

Therefore, what you are seeing as residue on the surface of the soil after a few days of watering is not fertilizer and will not harm your plants.

Do not modify the feeding routine for smaller plants.  Sixty years of experience and millions of lab (garden) experiments have established the importance of the fertilizer formula, the amounts, and the frequency of feeding.

What happens is that the fertilizer dissolves, then some of it quickly adheres to the soil particles and becomes “fixed” or unavailable to the plants.  This is particularly true of phosphate and potash.  Over time, those adhered particles are released and once again become available, and meanwhile the continued application of fertilizers each week feeds the plant.  When you stop applying fertilizers, there is a residual effect, and the plant continues to receive the benefit of the previous build-up for a few weeks.

Fertilizer will not burn or harm your small plants if used properly. It is supposed to be placed in the center of the bed between two rows of plants, and so will be several inches distant from plant stems.

Leaves should not come in contact with the fertilizer, because you should always be pruning any leaves that touch the ground.

Fertilizers With Sulfur – OK to Use In Mittleider Magic Formulas?

Q.  What’s the significance of the 11% sulfur in 34-0-0-11S fertilizer? Does it make a difference to us using the Mittleider method?

A.  Many common compounds used as fertilizer sources contain sulfur, including nitrogen, potassium, magnesium, zinc, manganese, iron, and copper. If sulfur is included you’ll see the term “sulfate”.

Sulfur is an essential plant nutrient, and is listed, along with calcium and
magnesium as a “secondary” nutrient. Plants use fairly large amounts of it.

However, sulfur lowers pH, so if you live in a high rainfall area with low pH you may want to find materials without sulfur for some of your elements. Good examples of alternative materials to use if you have this condition include magnesium oxide and potassium chloride.

Jim Kennard

Extra Phosphorus to Promote Growth of Root Crops – Good Idea?

Q.  I have been reading that phosphorus promotes root growth.  Would that mean that by adding a little extra phosphorus, one could increase the yield of root vegetables?

A.  Plants use a certain amount of phosphorus for optimum growth. That amount is usually about 1/2 as much as the amounts of nitrogen and potassium, and that’s why the Mittleider Weekly Feed formula has NPK in approximately a 2-1-2 ratio, and the formula is sufficient for all root crops, without adjustment.

Adding extra phosphorus to your garden, beyond that contained in Mittleider Magic Weekly Feed, will not improve your yields, but might actually upset the balance, and cause other elements to show problems.

Jim Kennard

Mixing Mittleider Fertilizers to Avoid Them Getting Wet or Hard

Q.   I’m told that when mixing the Weekly Feed formula there is a sequence of mixing that will counteract the natural water retention of chemicals, and thereby clumping.   If there is a sequence of mixing that will minimize the fertilizer getting wet or clumping, what is it?

A.  All the compounds used in fertilizers have oxygen in them, and several have hydrogen as well. A good example of one that actually has water in it is Epsom Salt, also known as magnesium sulfate, which has a formula of MgSO4(7H2O). This means that there are 7 parts of water in suspension with each part
of magnesium.

Both heat and mixing of the various compounds together lower the “melting point”, and so the goal in mixing is to avoid both of those conditions.  Mixing in a cool dry place with shovels is a good way to minimize the risk of your materials getting wet.

Another thing to do is to put the magnesium sulfate in last, after mixing the other ingredients.

Jim Kennard

Wood Ash as Fertilizer

Q.  I have been searching for information regarding ashes. Here is what I have found. Good clean ashes from burning untreated wood is good for your lawn and garden.  It is powdered nitrogen.  I intend to put it in my spreader and broadcast on my lawn. I barbeque with maple sticks that fall from my trees.   It should green it up nicely.

A. You have received bad information regarding wood ashes.  They contain no nitrogen.  The main ingredient is usually calcium carbonate, which can be good for your ground in measured amounts, if you have acidic soil (low pH because of more than 20″ of rain per year).  However, if you have alkaline soil you certainly don’t want the pH raised any more, so DO NOT put ashes on your alkaline soil gardens.

There is an essential nutrient – one of the “big three” – called potassium.  The compound in which it is most often found, and in which it is used as a fertilizer in the garden, is K2O and is known as potash.  The reason it’s called potash is because it was discovered to be an ingredient in ashes.

Care should be taken to know what you are doing before applying anything to your garden.  Wood ashes also contain heavy metals that might actually be bad for you.

I recommend anyone considering using wood ashes in their gardens read the materials listed below.  The first one is particularly well done.

I Can’t Find The Recommended Fertilizer Formulas, What Do I Do?

Q.  I’ve asked the co-op about 34-0-0.  They told me I have to have a farming licence to buy it.   I ran around to the nurseries and they acted like they didn’t know what I was talking about.  I’m going to try a local farmer and maybe I can buy it from him. Home Depot has a ? 24-3-3?  something like that. Is that close enough?  And no one has 16-16-16. Do I need to order that on line?
A.  If you have to use something other than 34-0-0, be sure to look carefully at the bag, and ask if necessary.  You want ammonium nitrate or ammonium sulfate as the source compound for your nitrogen, if possible.
Also, be VERY careful about using lawn fertilizer (24-3-3, etc.)  Much of the time lawn fertilizer is sold as a “Weed & Feed” blend, which has a broad-leaf killer in it.  If you get this in your garden it will kill your plants quickly.
I’ve never seen a situation where you can’t find a mix of npk that is somewhere between 10 and 20% of each.  And most of the time they are equal.  So, 10-10-10, 13-13-13, 15-15-15, 16-16-16, or 20-20-20 will all work.  And if you could find any with a 2-1-2 ratio that is better still.
If you have really looked and there are none of those available, write and tell me exactly what IS available, and we’ll help you figure a way to use combinations of other things you CAN get.

When to Use Nitrogen – Which Source of Nitrogen is Best

Q.  I want to apply nitrogen (8 oz/30′ row) after transplanting seedlings as directed.  My problem is that the recommended 34-0-0 ammonium nitrate is difficult to find.  This leaves 21-0-0 or 46-0-0.  Since the object from what I understand is to jumpstart the growth, I would think 46-0-0 would be better, with more than double the nitrogen of 21-0-0.  My question is what rate should I apply it since I don’t want to burn the new plants?. 
A.  Nitrogen fertilizer is available by itself in three commonly available compounds.  They are ammonium nitrate (34-0-0) of Oklahoma City infamy, which is the best source of nitrogen, ammonium sulfate (21-0-0), which is usually the second choice, and urea (46-0-0) which is usually the last choice.
Do NOT use nitrogen by itself, except for two times, 1) immediately after TRANSPLANTING young plants into the garden, at which time it is good to give your plants a boost to help overcome transplant shock and give them a quick start.  The amount to use is 1/4 ounce per running foot of soil-bed, or 8 ounces per 30′ bed.  And 2) if you see a nitrogen deficiency in your growing plants.  Consult the Garden Doctor books for deficiency corrective treatments.
Which compound is best to use?  If the weather is cold when you transplant, the 21-0-0 and 46-0-0 will not perform very well.  However, we do not recommend you increase the dosage, but we do encourage you cover urea with some soil.
Here is a brief recap of the reasons why 34-0-0 is the best and 46-0-0 is the worst nitrogen source.  34-0-0 is NH4NO3, including an ammonium portion and a nitrate portion.  The nitrate portion, NO3, is immediately available to plants, and that’s why this source is the best, especially in cold weather.  The NH4 portion must go through a chemical change to become available, and that doesn’t happen much in cold weather. 
21-0-0 is NH4(SO4)2, and thus has only the ammonium portion.  But it does have sulfur, which is an essential nutrient, and will tend to lower the pH, so if you are in a low rainfall area and the weather is warm, 21-0-0 can be good.  Remember, if you are in a high-rainfall area, that 21-0-0 can exacerbate your low pH acidity problems.
Urea – while it shows 46-0-0 as a percentage of nitrogen, has a chemical formula given two different ways – as CH4N2O, or CO(NH2)2 – both of which mean that the nitrogen is not in a form that plants can use it.  Instead the urea must undergo multiple chemical changes before it becomes available to your plants.  Meanwhile, because nitrogen in all it’s compounds is volatile and returns to the air, urea nitrogen is much more susceptible to loss in this way, and farmers who use it are counseled to apply it only beneath the soil surface, to minimize losses during the chemical changes.
Keep agitating your suppliers, and even your lawmakers, to make 34-0-0 available, and in the meantime use the others the best you can.
Two other alternatives you might consider, if they can be found, are calcium nitrate, which can also help with your calcium needs, and potassium nitrate – both of which can provide nitrogen in the NO3 form.  However, they are usually  more expensive than the other alternatives, and are primarily used in the greenhouse/hydroponic industry.
No matter which nitrogen source you use, remember to apply it, as well as all other fertilizers about 4″ from the plant stems and water them in thoroughly.

Fertilizing Before Planting – Manure, Minerals, or Nothing?

Q.  You mentioned that you added preplant fertilizer to your soil before planting seeds.  I would think that seeds and fertilizer are a bad idea. Shouldn’t you place the fertilizer in the beds you are transplanting established seedlings into, not in with the seeds you are starting?  It seems to me that adding fertilizer before planting seeds would be like trying to start the seeds with ocean water… Toooo salty….
A.  Has anyone else had the feelings expressed here – that because nitrogen might burn your emerging seedlings you shouldn’t fertilize the ground before planting?  It is a valid concern and needs to be addressed. 
First, let’s talk about the common practice of amending your garden soil by applying manure.  Many people who strongly advocate this, while at the same time accuse others of polluting the soil by adding “chemicals,” haven’t done their math.
I recommend you look at my article on this subject at (and while you’re at it, subscribe to the Foundation’s Sustainable Gardening Ezine), where I review this subject.
If you were to put 2″ of cow or horse manure on your 18″ X 30′ soil bed and till it into the top 8″ of soil, you would have added about 250# of manure containing 1% nitrogen to 30 cubic feet of soil.  That’s 2 1/2 pounds of actual nitrogen in 30 cubic feet of soil, or 2 1/2# nitrogen in about 3,000# of dirt.  This is 20 times as much as we recommend, and often a high enough concentration of nitrogen to burn newly germinating and emerging seedlings, and people can have very disappointing results after amending their soil in this way.
What does the Mittleider Method recommend?  We recommend you add 32 ounces of Pre-Plant Mix and 16 ounces of Weekly Feed Mix to that size soil-bed.  Pre-Plant Mix is mostly lime or gypsum.  These are base elements, rather than salts, and won’t burn your plants, so there’s no worry about the Pre-Plant Mix burning your new seedlings.  The element most responsible for burning tiny plants is nitrogen, which is in the Weekly Feed Mix.  Sixteen ounces – or 1# of Weekly Feed contains 13% nitrogen, so you will be applying just 2 ounces, or 1/8th of a pound of nitrogen in that same 30 cubic feet of soil.
Therefore, applying 32 ounces of Pre-Plant and 16 ounces of Weekly Feed to a single 18″ X 30′ Soil-Bed adds 1 part nitrogen to 24,000 parts soil, or 42 parts per million.  This concentration is not a problem for new seedlings, and is about 1/500th the concentration of ocean water, so the analogy used in the question is not accurate.
You will find Dr. Mittleider has addressed and resolved your concerns in every aspect of vegetable production.  I invite you to relax, follow the procedures accurately, and enjoy the ride to a great garden – no matter what kind of soil you have!