Homemade Organic Fertilizers
By Bryan O'Hara
Photo by Getty Images/aluxum
This article is excerpted from his book No-Till Intensive Vegetable Culture (Chelsea Green Publishing), available below.
Vegetable growers traditionally bring large amounts of nutritive materials onto their land to improve soil and plant function. Although adding volumes of compost and mulch is still the basis of fertilizing vegetables, these are often supplemented by modern fertilization materials. If these materials are concentrated, they can supply nutrient needs through very small additions of a only few pounds per acre, or even less.
On our 3-acre property, Tobacco Road Farm, we’ve developed our own formulas for side-dressing and foliar application. These recipes have been created for our particular soils and environmental conditions, including high organic matter, loam soils under the influence of intense pollution, and a generally degraded ecosystem. Because of our growing situation, our recipes are relatively complex, and we frequently alter the ingredients based on our assessment of specific crop needs, or because of field conditions or availability of materials. Simpler versions may well work in other situations, including yours.
The following recipes are provided as examples to offer insight into how materials can be combined, and in what relative volumes. The ingredient lists are offered simply to help stimulate your own thought process. We use Stage II materials the most because, in our situation, there’s often more than enough growth force to provide for initial leaf growth (Stage I). However, we might still utilize a Stage I recipe for cabbage head sizing. You’ll also find a recipe for a fruit-sizing (Stage III) solid material to apply by side-dressing, but on our farm, plants are often so large and difficult to access at that stage of growth that we frequently choose to rely on foliar fertilization instead.
To apply the liquid blends, we combine the ingredients in 100 gallons of water in a fertilizer tank. Then, we adjust the flow from the fertilizer tank to further dilute the blend with irrigation water at a ratio of about 1-to-20.
We often use a liquid-blend formula when we’re irrigating newly seeded beds. In this blend, we choose to use a relatively weak liquid seaweed product; if we’re using a concentrated form, we cut back on the amount added. We include fermented plant extracts if they’re available; carrot and beet extracts are our favorite for seed treatment. (See “Korean Natural Farming Basics” for instructions on making fermented plant juice.) To gather vermicompost extract, we water the vermicompost bins about an hour or so in advance, collect the runoff, and immediately use it. Liquefied compost extract is a good substitute that’s easy to make: We put about 1 gallon of compost in a 5-gallon bucket and fill it with water, and then stir vigorously, strain, and use immediately.
Photo by Getty Images/jxfzsy
- 20 fluid ounces liquid seaweed
- 20 fluid ounces apple cider vinegar
- 10 fluid ounces fermented plant juice (recipe in “Korean Natural Farming Basics”)
- 20 fluid ounces carrot or beet plant extract (a type of fermented plant juice)
- 20 fluid ounces Epsom salt (magnesium sulfate)
- 5 gallons seawater (or 40 fluid ounces agricultural sea salt)
- 5 gallons liquid vermicompost extract
- Small amounts of other trace elements, such as molybdenum, boron, and sulfur (optional, if deemed necessary)
The quantities listed here will make enough liquid to cover roughly 5,000 square feet. We apply by hand via high-volume hoses with at fan-spray-pattern nozzles attached, covering the entire surface of newly seeded beds, at a rate appropriate to the soil condition, to bring the seed to germination.
Stage III Fruiting Solid Side-Dress
It can be logistically difficult to apply a solid side-dress alongside plants in the fruit-sizing period, but we’ve developed a recipe we can make use of when we can reach the plants. We use old compost material for this blend, often materials that’ve been left behind from our more active composting piles. Regular wood ash will serve, although we prefer to use high-silica ash from the burning of materials from the exteriors of plants.
Photo by Getty Images/alicjane
- 1 wheelbarrow of aged compost
- 1 quart bone meal
- 1 quart soft rock phosphate
- 1 quart raw milk
- 2 quarts dry seaweed
- 1 quart wood ash (high-silica content, if possible)
Foliar Spray for Fruit Ripening and Disease Prevention
We use this foliar spray for fruit ripening and disease resistance in August. Water for foliar treatments is probably best if it’s not treated with antimicrobial materials, such as those found in municipal water. Well water is our choice, although water from an active stream may be even better. Rainwater in our area is so highly contaminated that it may well be antimicrobial, but rainwater may work well in other regions. We often set the well water in the sun for a day before using it in our foliar sprays. This leaves the water in the best possible state for use in our conditions. About 15 to 20 gallons of foliar spray are applied per acre, so the appropriate number of 5-gallon buckets are filled with about 3 gallons of water apiece, and materials are then added in proper proportion. All the following volumes of materials are per 3 gallons of water.
Photo by Bryan O’Hara
- 1 pint seawater, or 1 fluid ounce mineral sea salt (SEA-90)
- 4 fluid ounces high magnesium-chloride seawater (SEA-CROP)
- 1 fluid ounce liquid seaweed (highly concentrated)
- 1 fluid ounce apple cider vinegar
- 1/2 fluid ounce vinegar eggshell extract
- 1/2 fluid ounce vinegar bone extract
- 2 fluid ounces fulvic acid extract
- 1/2 fluid ounce liquid soap
- 1/2 fluid ounce Oriental Herbal Nutrient
- 1 fluid ounce comfrey fermented plant juice (FPJ) (see “Korean Natural Farming Basics” for recipe)
- 1 fluid ounce nettle FPJ
- 1 fluid ounce plantain FPJ
- 1 fluid ounce purslane FPJ
- 1 fluid ounce rutabaga FPJ
- 1 quart horsetail tea
- 1 quart extracted indigenous microorganisms
- 6 fluid ounces raw milk
- 2 fluid ounces raw honey
- Dusting of Biodynamic 501 (ground quartz preparation)
Learn more about fermented plant juice in “Korean Natural Farming Basics.”
Stage I Leaf Liquid
We developed this formula for the first stage of plant growth, referred to as the “leaf stage.” It supplies a sugary nitrogen source for increased soil bacterial activity and nutrient release, along with some calcium and trace minerals. This gives plants a boost when they’re lagging in growth force (which is a relatively rare condition on our farm). We often leave out the liquid fish, and sometimes we prepare a simplified blend of molasses, seawater, and milk. Calcium nitrate or sodium nitrate can be substituted for the liquid fish. We apply this formula alongside the growing crops using flat-fan-spray-pattern hose ends, in a similar manner to the “Seed-Starting Liquid.” This volume of liquid will cover roughly 5,000 square feet of growing crops.
Photo by Bryan O’Hara
- 80 fluid ounces liquid fish (or other appropriate soluble nitrogen material)
- 160 fluid ounces molasses
- 20 fluid ounces vermicompost extract
- 160 fluid ounces seawater (or 10 fluid ounces agricultural sea salt)
- 20 fluid ounces hydrated lime (caustic material, careful handling required)
- 160 fluid ounces raw milk
Stage I Leaf Solid Side-Dress
Photo by Bryan O’Hara
Because of our environmental and soil conditions, solid side-dressing materials are all compost-based. They’re essentially compost piles specifically built for the various periods of growth. Often, they’re relatively small, contain many added minerals, and are mixed and used within short periods of time. It’s rare that we need to side-dress crops to promote leaf growth, but here’s a formula we’ve used for that purpose. The compost for this recipe is one that included a high percentage of cattle manure in the initial mix.
- 1 wheelbarrow full of manure-rich compost
- 1 quart molasses
- 2 quarts coffee grounds
- A splash of seaweed
We mix up this material a few days before use, but you can also mix and apply it immediately if necessary. Usually, we make a pile on the ground and hand-mix with pitchforks, but if a particularly large batch is needed, we assemble and mix it with a loader tractor. Then, we scoop the mixture into buckets, rake back the mulch alongside the plants, apply the side-dressing, and then return the mulch to its former place. Though application rates vary, a 5-gallon bucketful is usually enough to side-dress about 40 row feet. Water it in well.
Stage II Flowering Liquid
This liquid side-dress fertilizer helps bring a crop into flowering. It can also be applied once flowering has begun. The milk and rock phosphate provide increased calcium and phosphorus levels; the micronutrients encourage flowering, as does the phosphorus; and the molasses serves as a high-carbon buffering agent. The rock phosphate is very finely ground. With occasional stirring, it stays suspended in the liquid to some extent. We make a similar liquid to promote fruit sizing (Stage III), using the addition of ash from burning high-silica materials to provide a reactive potassium and silica source.
Photo by Bryan O’Hara
- 1 gallon raw milk
- 1 gallon molasses
- 8 fluid ounces liquid seaweed
- 1-1/2 gallons soft rock phosphate
- 8 fluid ounces soluble manganese sulfate
- 4 fluid ounces soluble zinc sulfate
- 2 fluid ounces magnesium oxide with 8 fluid ounces vinegar added to react
Stage II Flowering Solid Side-Dress
This is a solid material for side-dressing during the flowering stage. Our recipe uses compost and added mineral materials. Because this material is very rich in mineral amendments, we use it at a lower rate than the “Stage Leaf I Solid Side-Dress,” often about 5 gallons to 80 row feet. Prepare this blend a few weeks ahead of time and let it sit. We often use the loader tractor to assemble this material, and we apply it in the same way as the “Stage I Leaf Solid Side-Dress.”
- 1 wheelbarrow full of high-carbon compost
- 2 quarts soft rock phosphate
- 6 quarts gypsum
- 8 quarts diatomaceous earth
- 1 quart dry seaweed
- 2 quarts wood ash
- 8 fluid ounces molasses
- 4 fluid ounces sodium borate (Solubor®)
- 2 quarts vinegar mixed with 6 fluid ounces magnesium oxide
- 8 fluid ounces manganese sulfate
Bryan O’Hara has been growing vegetables for a livelihood since 1990 at Tobacco Road Farm in Lebanon, Connecticut. He works with natural systems to build a highly productive, vibrant growing system. This article is excerpted from his book No-Till Intensive Vegetable Culture (Chelsea Green Publishing), available below.
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