Natural Fertilizers for Garden:15 organic fertilizer dosages & recipes

Currently, synthetic fertilizers for gardening are very numerous on the market. However, Gardeners are now focusing on more natural products for the well-being of your garden because organic fertilizers are biodegradable, renewable sustainable and environmental friendly. There are also lots of benefits use nontoxic organic fertilizer instead of chemical fertilizer.


15 Organic Fertilizer  for Organic Gardening

Natural fertilizers (organic fertilizers, mineral fertilizers) are made from vegetable matter, mineral, animal matter or animal manure.

Specific organic fertilizers are complete balanced mixtures, very rigorously dosed containing all the constituents necessary for the lifecycle of the plant.

Increasingly sought after in organic agriculture, natural fertilizers have many advantages. They promote the nutritive qualities of the soil by protecting it from erosion naturally. Also, these fertilizers are an ecological alternative to herbicides. They make it possible to avoid the development of weeds.

The nitrogen (N) contained in these fertilizers is of organic origin. The phosphorus (P) comes from phosphate rock. The beet vinasse usually provides the potassium (K).

Natural Fertilizers of Animal Origin

Blood Meal

Another organic fertilizer, consisting of water-soluble nitrogen with slow release, blood meal is an excellent 100% natural fertilizer, perfect for crops deficient in nitrogen. The dried blood brings nitrogen which acts on the growth and the color of the foliage. It is suitable for rosebushes and perennials at the beginning of the season. Its action is effective and durable, safe for the roots. Nitrogen promotes growth and even influences the color of the foliage! Of animal origin, its effect is fast and durable, without risk of burning for the roots.

Dosage:Trees: 12,50 kg / 100 m²
Vegetables, flowers: 75g / m²
Grass: 50 g / m²
Organic compost: 1,5 kg for 1 m3

Blood Powder is a quick-release “whiplash” fertilizer. It immediately stimulates the growth of plants; it will be used in the spring, from March to June.

Guano Organic Fertilizer

Guano is made up of seabird excrement. Guano offers a perfect balance of nitrogen, phosphorus, and potash. Also, it is rich in trace elements. Like blood meal, it is a quick-release fertilizer, good for greedy plants and turf. Guano immediately stimulates the growth of plants; it will be used in the spring, from March to June and September to November.

Dosage: 2 to 4 kg / 100m² or 20 to 40 g / m²

Bone Powders

This very light and soluble natural fertilizer. It is an organic fertilizer that can be used for the preparation of compost and the manure of the lawn.

Due to its progressive action, this powder acts on the growth of the roots. There are marine bone powders (see below) and others made with bones and meat. In this case, it is a fertilizer rich in nitrogen and phosphorus. It is used in complementarity with the compost. It can slightly increase the pH of the soil. It must be incorporated superficially.

Fishbone Meal

The fishbone meal is an organic fertilizer, rich in phosphorus, which fits all plants by acting on the root growth.

Due to its progressive action, it promotes flowering, resistance to cold, diseases and insects. It presents no danger for the plant.

Of marine origin, the ground bone powder stimulates the soil biology and acts on the growth of the roots; its action is progressive and durable and without risk of burning. Phosphorus and nitrogen are involved in the main physiological activities of plants. They promote growth, early maturity, and resistance to cold, disease and insects. It is suitable for all types of soil, even limestone.

Period of use: October to March
Dosage  : Tree 2kg / 100m² / Vegetables, flowers, grass: 100 g / m²

Horn Powder

Of animal origin, the dry horn powder has progressive action. It does not burn the roots.

It releases organic nitrogen very slowly and thus nourishes the plant throughout its vegetative cycle. It promotes the rooting of plantations or maintenance of trees, shrubs, bedding plants, and rock gardens.

It is used at planting time, whether in spring or fall, February-June and September-November

Dosage: Trees: 12,50 kg / 100 m² – or 100 to 150 g per foot
Plants of heather and rock plants: 50 g per m²
Fruit and ornamental trees: 300 to 500 g per subject
Vegetables, flowers: 75 g / m²

Natural Fertilizers of Mineral Origin

Phosphate as Fertilizer

Natural phosphate is fertilizer is recommended for acid soil and little limestone that is used as an alternative to fish bones.

Dosage: 2 to 4 kg / 100m² or 20 to 40 g / m²

Rock Powder or Basalt

This mineral fertilizer is a powder from a finely ground volcanic rock. Rich in siliconcalciummagnesium and trace elements, basalt powder allows the plant to cope with adverse climatic periods and strengthens it against certain diseases by increasing the resistance of its cell tissues.

According to agricultural engineers, we must avoid any nitrogen supply on young seedlings. Also, do not apply manure to plants that look sick and dry. Water first with water, then again a few days after application.

The rock powder, depending on the rock used, will bring calcium, magnesia, iron, or potassium to your soil and can thus enrich it in essential elements to its growth. The finely ground volcanic rock powder is also called basalt. It is rich in silica, which improves the resistance of plants, and in trace elements, to fertilize the soil.

  • The rock powder of rather coarse granulometry (0.5 to 2 mm) is used to soften heavy clay-type terrain.
  • The fine-grained rock powder (0 to 0125mm) serves as a sand-like draining element or as a spray on the foliage.

Fertilizers of Vegetable Origin

Nettle Manure

Nettle and its fertilizing virtues are no longer a secret.

Rich in minerals, trace elements, and vitamins, nettle manure is a real growth promoter for all plants. It is thus used as an insecticide or in the treatment of certain diseases.


Comfrey is a wild plant known since antiquity for its medicinal virtues used as a natural fertilizer.Less consumptive to nitrogen than nettle manure, comfrey has potassium, calcium, magnesium, copper, zinc, manganese, iron, and boron. It is used in the relay with nettle manure and will promote the flowering and fruiting of plants requiring a fertile soil.

Castor Cake

Castor cake is used all year round as an organic fertilizer and as a repellent against rodents.

Of vegetable origin, castor cake is obtained after trituration of castor seeds. Its action is progressive and sustained. It has insecticidal properties and a repellent effect on rodents, especially Norway rats and field rats.

Castor cake is a very good natural fertilizer for lawns: it is used as a primary fertilizer and maintenance, in the garden and on the grass. Caution: Castor cake presents a danger for domestic animals, well respect the recommendations on the packaging.

Dosage: in maintenance: 20 to 25kg / 100 m ² or 200 to 250 g / m ²
In fertilization of bottom: 40 to 50 kg / 100m ² or 400 to 500g / m ²

Dried Green Algae

These green marine plants, once harvested and dried and reduced to powders, transmit beneficial substances for the plant that stimulate its growth and its resistance to diseases.

Before the Second World War, in Brittany, there was a practice of using specific varieties of algae as a fertilizer to improve soils, especially black shore weed such as Fucus Kalban, Ascophyllum Korreor Bezhin du. The coastal populations of northern Europe shared this practice of enriching soils with algae.

Algae were collected as early as April-May, then dried and stored, and sometimes mixed with manure to spread to the land after harvest. In order not to “burn” the land, too many varieties of iodine-rich algae (kelp) were avoided by respecting volumes per hectare (20 to 30 tons/ha).

Liquid Algae

Liquid algae are rich as fertilizer in minor elements and potassium. They also contain nitrogen, phosphorus, growth hormones, amino acids, natural antibiotics, and enzymes. They are used to stimulate the growth and flowering of plants and increase their resistance to pests and stresses (wind, cold, drought, transplantation).

They can also be used to restore vigor to diseased or weak plants and to meet the needs of the most demanding plants. Liquid algae are generally utilized in foliar fertilization, but they can also be mixed with water.  Dose: 10 ml / l of water.

Natural Fertilizers Against Potash Deficiencies

Potash (K) is essential for the formation of roots and tubers. A lack of potash is easily seen: dead leaves, soft stems, browned potato tops, beans that give little. Vegetables are poorly preserved. The top leaves of the fruit trees are thinning early. (To know more about potash as fertilizer)

Organic Potash

It is a plant-based fertilizer that is easy to mix. Potash comes from beet vinasse. This natural fertilizer is an excellent source of potash powder, easy to mix.

Dosage: 2 to 3 kg / 100m² or 20 to 30 g / m²
Period of use: from February to November

In the end, if none of these natural fertilizers suits you and you prefer to keep it simple, you can always buy liquid organic fertilizer, ready to use.

Natural Fertilizer for Geraniums

For geraniums, keep the stems and leaves of your geraniums when you clean them. Macerate in water for 10 to 15 days. Water your geraniums with the resulting decoction.

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