Life Well Inspired

How to Fertilize the Vegetable Garden Without Chemicals

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If you are looking to fertilize your vegetable garden without chemicals like Miracle-Gro it will require an understanding of plant nutrients and organic fertilizers. Vegetable gardening can be supremely rewarding and incredibly frustrating. If the plants have good quality soil and the nutrition they need, they thrive.  We, in turn, are blessed with a lot of veggies and very little pests and disease problems. That’s the supremely rewarding part. If our garden soil is less than good quality and the plants don’t have the nutrition they need, things take on a very different story! 

Chemical fertilizers and organic fertilizers work in two very different ways.  A chemical fertilizer like Miracle-Gro simply gives the plant a synthesized version of a nutrient typically made in a healthy soil.  It simply gives the plant a meal and the plant will require regular “meals” in order to stay healthy and produce what it is supposed to.  In contrast, natural fertilizers not only give the plant a meal but amend the soil so that it is able to provide the nutrients the plant needs.  As the soil becomes healthy, less “meals” are required. If you’re like me, you would rather stay away from commercial, chemical fertilizers that are not natural and/or organic.  

How do we fertilize the vegetable garden without chemicals?  How can we grow vegetables organically and help the soil provide the nutrients the plants need?  

The answer to fertilizing the vegetable garden without chemicals has two parts. There’s a long term plan and a short term plan. The long term plan involves amending the soil with compost and organic matter while mulching to retain moisture. But it takes time to build healthy soil. 

It is a good idea while building fertile soil to do a generic organic type fertilizer at planting and during the growing season. These are usually lower N-P-K numbers than a conventional fertilizer but they will still be effective.  It takes less of the natural to get good results because the plant already knows the substance. 

To understand what kind of fertilizer you need, you first need to understand a little about plant nutrients and what plants need.  The three most important nutrients plants need are nitrogen, phosphorus, and potassium.  On the fertilizer container you will often see three numbers that look like this, as an example: 10-10-10. The first number stands for nitrogen(N), the second for phosphorus(P), and the third for Potassium (K).  This is also referred to as N-P-K. 

The plant uses Nitrogen for leaves and plant growth, Phosphorus for root health, and potassium for fruit production. So when choosing a fertilizer, it is important to know what fertilizers to match up with what plant. For example, you wouldn’t need a fertilizer high in potassium to support fruit production for your row of lettuce. It would be much more appropriate for a crop of tomatoes or peppers because we eat the fruit of those plants. 

When you look at the three numbers on the fertilizer bag, they tell you how many parts per million (ppm) of each nutrient is in the formulation. The Garden Professors recommend “a ratio of about 5-1-2 or 5-1-3 for an N-P-K ratio in a general use fertilizer” because of how nutrients are absorbed so that you can absorb a buildup of a single nutrient and throw the soil balance out of whack. 

General Fertilizers

There are two general types of all-purpose fertilizers: a liquid and a granular. They can be used regularly throughout the season but you will need to experiment and see which one works best with your soil.  Although these are organic, they behave in a similar way to Miracle-gro in that they provide a meal without amending the soil.  However, these are helpful because they use the natural forms of the nutrients instead of a synthetic versions.  

Neptune’s Harvest– This is a fish emulsion liquid and needs to be diluted in water to make the final fertilizer you will apply to your plants. Fish are amazing when it comes to nourishing plants. The Indians used to bury a fish when they planted their corn, beans, and squash in their fields. They had the companion planting and the fertilizer all wrapped up together. Hydroponics circulates the water from fish tanks or ponds through the growing system to feed the plants. 

Agway’s Organic Fertilizer is the granular fertilizer that has always been a staple in my dad’s shed. He always uses it when planting and then side dresses with it later on in the growing season. This is my fertilizer of choice, too.  If you don’t have a farm store that sells Agway products near you, there are still other great options.

You can find a selection of organic granular fertilizers here.


Nutrient Specific Fertilizers

Sometimes, however, we need help quickly. We need to make nutrient adjustments to a plant that’s showing signs of deficiency. Thankfully there are nutrient specific fertilizers that will give an extra boost of a specific macro-nutrient and amend your soil as well.  You would use these any time there’s a deficiency showing up on the plant’s leaves, as a top or side dress to make sure the plant has the nutrients it needs, or in combination with the organic matter you are using.  

Bone Meal 

Bone meal is exactly what it sounds like- ground up bones. Usually it comes from bovine bones that have been steamed and cleaned so it is perfectly safe and disease free. It is an excellent source of phosphorus and calcium which supports the plants flowering and root growth. 

It is considered a slow release fertilizer and works best when the soil ph is less then 7. Because phosphorus combats the high nitrogen levels from heavy composting, it is ideal to use bone meal in combination with rotted manure. It is also considered organic matter and therefore feeds the soil microbiome as well. 

How to use bone meal

  • Add to the soil when planting fall bulbs for better root growth resulting in better blooms
  • Use it during the growing season by gently working it in, being careful not to disturb the roots. 
  • Use sparingly, as excess phosphorus in the environment is what triggers the algae blooms that cause problems. 
  • It can be toxic to dogs, so be sure to work it in well and keep the bag in a place where it is out of reach. 

While application recommendations may vary according to the manufacturer, here are some basic guidelines.  

  • 2 tablespoons per planting hole
  • ½ cup per cubic foot of potting soil
  • 10 pounds per 100 square feet of garden bed
  • 1 pound per 2” of trunk diameter 

You can find a selection of bone meal here.

Blood Meal 

Blood meal is also exactly what it sounds like- dried ground up blood. This also typically comes from a bovine or swine source and is a very concentrated source of nitrogen. It is also considered a slow release fertilizer that can raise the ph of the soil. It is ideal to use blood meal in combination with compost that is high in carbon.

How to use blood meal

  • Because of its high concentration of nitrogen, too much can prevent flowering and fruiting and even kill the plants. 
  • Green leafy vegetables will love blood meal because the the leaves are used for food, not the flower or fruit. 
  • It is specifically useful to plants that prefer a higher ph like squash, peppers, radishes, and onions.  
  • Plants that are weak with yellow/pale and/or wilted leaves will benefit from the nitrogen in blood meal. 

While application recommendations may vary according to the manufacturer, here are some basic guidelines. 

  • Mix in soil at the rate of 1 cup per 20 square feet of garden bed.
  • Dilute with water to use as a liquid fertilizer at 1 tablespoon per gallon. 

You can find a selection of blood meal here.

Worm Castings 

In plain terms, worm castings are nothing more than worm poop. But it is incredibly nutritious for plants and an excellent amendment for garden soil. It is rich in both macro and micro nutrients- nitrates, phosphorus, potassium, calcium, manganese, magnesium, copper, zinc, cobalt, borax, iron, and carbon. It also contains the minerals plants need for healthy growth.

Maybe more importantly is the fact that it contains bits of organic matter, beneficial bacteria, and earthworm eggs as well.  It typically has 50% more humus than is found in topsoil. 

The presence of earthworms in the soil is an indicator of healthy soil and using earthworm castings can help increase how many are in your garden, therefore greatly increasing the fertility of your soil. 

Worm castings are also considered slow release but it is available for the plants right away when applied to the soil. It will never burn your plants. 

How to use earthworm castings 

  • It is known to enhance seed germination rates. 
  • It is helpful for plant growth
  • It encourages fruit production 
  • Is immediately available to plants when applied. 
  • Has a neutral ph 
  • It truly amends the soil as it increases the soils ability to produce nutrients not just adjusts nutrient levels. 

While application recommendations may vary according to the manufacturer, here are some basic guidelines. 

  • Use ¼-½ cup per 100 square feet worked into the top few inches of soil. 
  • Make a tea with 2 cups of worm castings per 5 gallons of water left to sit overnight before use. 

You can find a selection of worm castings here.


Egg Shells

Used eggshells don’t have to go in the garbage!  They are very useful in the garden providing calcium in the form as calcium carbonate, which is the same thing as lime. It consequently has the same ph lowering effect as lime. Calcium supports healthy cell walls which affect the structure of the plant and it’s leaves.  

It is not only useful for feeding the plants, but it can also be used to deter pests because of the sharp edges of the shells when crushed and spread around the base of the plant. 

How to use eggshells in the garden 

  • Worked them into the soil in the fall and leave to breakdown over the winter
  • It is also acceptable and helpful to mix into the soil in the spring, too. 
  • Eggshells can be used as pots for starting seeds and can be planted in the ground right with the seedling. 
  • The shells help add air the soil. 

While application recommendations may vary according to the manufacturer, here are some basic guidelines. 

  • The crushed shells can be spread on the top the soil around the plant and can be worked into the soil. 
  • Up to 20 shells can be added to boiling water and left to set overnight creating a potassium and calcium rich tea. 


Coffee Grinds

Both used and fresh coffee grounds can be used in the garden but each provides a separate benefit and are used for different things. Used grounds have a neutral ph and can be used to add nitrogen and organic matter to the soil. Fresh (unused) coffee grounds are acidic and raise the ph of the soil which are great for using around plants that need an acidic soil like blueberries and hydrangeas. 

It is considered a slow release fertilizer but it is not immediately available for the plants. The nutrients become available as the grinds begins to break down. Coffee grounds are also considered organic matter which makes them excellent worm food. 

How to use coffee grounds in the garden. 

  • Spread fresh (unused) grounds around the base of acidic loving plants. 
  • Work used grounds in the soil to improve water holding capacity. If left on the top of the ground it will do the opposite and for a barrier preventing water from absorbing. 
  • It is considered green compost material so make sure your grounds are getting added to your compost pile as well. 


Epsom Salts

Epsom Salts are an excellent source of magnesium that can be used in the garden. Magnesium plays an important role in blooming, the chlorophyll production that creates the enhanced green color of the leaves, and it promotes bushy growth. Epsom salts is made of both magnesium and sulfur which help the plant take up nitrogen and phosphorus. 

While magnesium is not a macronutrient, it plays a large role in fruit development for tomatoes.  If you continually struggle with blossom end rot,  the bottoms of tomatoes rotting before or as they ripen, then adding this to the soil will really help you conquer this problem. 

How to use Epsom salts in the garden 

  • Tomatoes and peppers love magnesium. Use a tablespoon at planting, when the plant is blossoming, and again when fruit is set. 
  • Avoid using it around beans, leafy veggies and plants that prefer low magnesium levels. 
  • Roses appreciate the foliar spray applied in spring as the plant begins to leaf out and again after flowering. 

While application recommendations may vary according to the manufacturer, here are some basic guidelines. 

  • It can be sprinkled on and mixed into  the soil. 
  • A foliar spray can be made with 2 tablespoons or Epsom salts per gallon of water.  

You can find a selection of Epsom Salts here.



According to,  milorganite is a substance “composed of heat-dried microbes that have digested the organic matter in wastewater.”  It is considered a slow release source of nitrogen and iron that doesn’t burn plants or cause excessive root growth. It is a soil amendment and is a source of food for the beneficial bacteria and critters in the soil. It also helps hold moisture in the soil. 

How to use Milorganite

  • Typically this is used with lawn care but it can also be beneficial in the garden also. 
  • Work it into the soil at root depth at planting along with 2-3” of organic matter. 

While application recommendations may vary according to the manufacturer, here are some basic guidelines. 

  • Use 4.5 pounds per 50 square feet of garden bed 
  • Work a  ½ cup into the soil around each plant. 

You can find a selection of milorganite here.

The best fertilizers not only feed the plants but amend the soil so that the soil can produce the needed nutrients independently. A truly fertile soil that has a variety of organic matter consistently added to it will not need outside nutrient additions or help fighting pests and diseases.  

As you are beginning your gardening journey or if you are experiencing less than optimal results, it is wise to order a comprehensive soil test through Cornell Cooperative Extension or a private lab yearly to really understand what your soil needs. This is the fastest way to identify and correct potential nutrient problems that may prevent success in your garden. 

Gardening is the journey of creating fertile soil and our results are the proof of progress on our journey.  Your efforts to work with nature will most definitely be rewarded with greater nutrition for your body, less gardening problems, reduced work time in the garden, and a greater satisfaction with your efforts.  

What is your favorite organic fertilizer or natural way to feed the plants in your garden?  Tell me in the comments  below!

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