What Kind Of Fertilizer is Best For Organic Gardening?

People that are new to natural gardening frequently assume that organic garden plant food is just an additional kind of plant food in a bag. That is most certainly not the case, there is more that goes into organic gardening than what you feed your plants. We will discuss the three main ways you can deliver fertilizer to your garden soil, the benefits and draw backs of each so you are better informed on what to use.

There are many types of fertilizers you can use in your garden. Not just the NKP ratio but also what makes us the material in the fertilizer. The NKP ratio, or Nitrogen to Phosphorus to Kalium (latin for Potassium) will dictate the ratio of one to the other and the concentration of each in a given quantity of fertilizer. A 10-10-10 is a fairly common mix and as it states has an equal mix of each at a concentration. In this case you would need 10 pounds of fertilizer to add 1 pound of each nutrient to your soil. When the lix is say 10-5-5, you then have twice as much nitrogen as phosphorus or potassium and 10 pounds of fertilizer would add 1 pound of nitrogen but only 1/2 a pound of the others to the soil.

Why Organic Fertilizer

Organic fertilizer is made from natural material found in nature. The materials came from nature and can be broken down and returned without harm to the soil, water supply, animals, or most importantly, you! Not only are most commercial fertilizers made from some chemical process but the method to obtain them is very resource rich. The “mining” of some of the materials that are used to create the synthetic fertilizers can end up in the waterways and cause havoc on the local ecology, such as the case with some accidents involving phosphate mines here in Florida. For all these reasons, organic fertilizers make the most sense, and are equally effective.

Liquid Fertilizer Organic

There are many good reasons to use liquid organic fertilizer, and probably the one most like is the ability to spray it on your plants or vegetables. It is a super simple and convenient way to apply your organic fertilizer. All you need is to buy the solution then depending on how you are set up, just spray on the plants as uniformly as you can for the desired amount of time.

The other good reason to use liquid organic fertilizer is the short amount of time it takes for the fertilizer to make an impact on your plant growth and health is very short, usually within a few days to a week. That makes sense as the fertilizer itself has already been dissolved and can be more easily absorbed by the plant to use.

Though that is not the end of the story. While the convenience of delivery and fast acting nature can be a plus, there are a few shortfalls with liquid organic fertilizer. The first being that spraying is inevitably more wasteful. You will end up spraying fertilizer all over an area, some will not land on your plants. Another issue is, when spraying most of the liquid organic fertilizer ends up on the leaves and not on the roots. While the leaves will absorb the liquid the better route is through the roots up to the leaves. Liquid organic fertilizer does little to create soil health. Maintaining and when fertilizing, building up soil health is the most important aspect. So in this main area, liquid based fertilizers fall short.

Granular Organic Fertilizer

Far more readily available at your local garden store or big box store than liquid organic fertilizer, organic fertilizer in granular form comes in bags or boxes of various sizes. You can expect to pay between $10-$20 for a 5lb box or bag of organic fertilizer depending on the quality. This can be applied to soil itself and mixed in, which is what you would normally do when starting a new planting, or by side dressing when you are amending the soil as your plant grows. When mixing into your soil before planting, apply 5lbs of organic fertilizer per 100 square feet. As the plant sprouts and then if growing, apply about a handful around each plant. I find that the same 5lb box will allow me to side dress around 50 plants.

Granular organic fertilizer doesn’t require any special equipment to apply it. All you need is a glove and a walk with the bag. It stores well so long as you keep it out of the sun and away from moisture. The best reason to use this method of delivering fertilizer is that it promotes and builds up soil health. When your soil is well balanced with a high mix of all essential nutrients your plants will thrive. Most non-organic fertilizers focus on just NKP, and if you read the labels that is all they really add to them. You can also find granular organic fertilizer in slow release formulas which is highly recommended.

There are many producers of granular organic fertilizer and as mentioned are easy enough to find locally. My favorite brand to use is Down to Earth. They make specific blends for various applications, such as vegetables, roses, citrus, acid loving fruit trees, and they also sell the base ingredients. Kelp meal, bone meal, langbeinite, bat guano, and a bunch more for when you need to specific in what you need to be specific on what you add.

Garden compost

Any list what be incomplete if it didn’t have organic compost. When talking value nothing beats good compost. Of course if you make it yourself it will be near free, but that takes time and effort that most won’t want to do. If you buy and have delivered a yard of compost in my area it costs $130, if you equate that per bag it would be less than $3/bag. A very affordable price for a whole lot of compost. By its nature compost is already a slow release medium. It also adds organic matter back to your soil that is lost while it breaks down from the sun, rain, and plant demands. You can of course buy compost in bags at your local garden or big box store, they range in price from $8-$15 per bag depending on the bag size and quality of the compost.

If you garden often then you know it’s tough to be successful without compost. You would need to be buying new soil every season if you aren’t amending with compost. Which also means it becomes that much more expensive and less productive. So consider this a necessity. Creating your own isn’t hard, many have created their own compost even in urban areas. Though it does take time to breakdown and you will need some space away from your home as decomposing organic material will give off odors and attract critters. Which again is why many don’t even bother.

One thing about compost, depending on if you make your own or buy it, is that often it isn’t going to be well balanced. Especially if you are creating it yourself, that would take skill and knowledge that most don’t have and don’t have time to learn. So you will still need a fertilizer to balance it out. But armed with a good compost containing good organic matter and valuable nutrients couple with a high quality fertilizer you will have great success growing plants or vegetables in your garden.


All these different materials bring a different mix of proteins, minerals and various other nutrients to your soil and plants. Choosing the right one or combo is going to depend on many factors. I consider myself a serious gardener and year after year I rely on my soil to be able to produce beautiful flowers and edible vegetables. In my case i have good quality organic compost delivered twice a year and use Down To Earth products to amend my soil as I go during the season. Happy growing!

Posted by Amaral Farms

HI and thanks for visiting my blog. I guess I would say I have always been a gardener at heart. My parents gardened and I helped them from a young age. As an adult I took to the organic movement and began gardening using almost exclusively organic methods. My focus has shifted the last decade to add heirloom gardening to the mix. By no means an expert, I do enjoy it and spend at least a few hours a week dedicated to it. I hope you enjoy and gain some value from my blog. Check out my tips for growing tomatoes in pots.