If your plants need a boost in addition to the compost you already use to feed and build your soil in the lawn or garden, choose from one of several organic fertilizers.
Nutrients Required for Healthy Plants
Plants require three major nutrients for healthy growth: nitrogen, phosphorus, and potassium. Nitrogen is vital for chlorophyll production, so nitrogen-deficient plants appear yellow and stunted. Phosphorus helps plants grow healthy root systems. Without adequate phosphorus, plant growth tapers off and leaves develop a distinct blue coloration. Potassium is necessary for flower and fruit development. Organic gardeners will be sorely disappointed in plants lacking potassium, for the plant's flowers are sparse and fruits underwhelming.
Additionally, there is a range of trace elements that plants need in small quantities to flourish. The most important trace elements include boron, copper, iron, manganese, molybdenum, and zinc. Although only a few organic fertilizers contain the trace elements, a liberal top-dressing of compost should meet all of the plants' needs for these nutrients.
Organic or Chemical Fertilizers
Botanists may argue that plants don’t distinguish between organic and inorganic fertilizers. Whether the plant gets its nutrients from compost and handfuls of organic meals, or whether the plants receive weekly dousing with chemical fertilizer, the plants will grow. However, chemical fertilizers do nothing to enhance the biological activity of the soil. Furthermore, the production of chemical fertilizers can yield toxic by-products, such as ammonia. Finally, the production of chemical fertilizers uses significant amounts of fossil fuels.
Bone Meal
Commonly used as a fall bulb booster
Rich in phosphorus
Stimulates root growth
Blood Meal
Releases nitrogen quickly into the soil
Use early in the season to prevent tender growth that could be damaged by early frosts
Relished by carnivores, so don’t use if digging dogs or cats are problematic
Beware of inorganic formulas, which contain added potassium
Hoof and Horn Meal
Excellent source of slow release nitrogen
Apply early in the season to allow time for decomposition and plant absorption
Liquid Manure
Make at home by filling a burlap sack with barnyard manure and soaking in a 50-gallon drum of water for one week
Use as a foliar feeding spray
Supplies the full range of trace elements
Liquid Seaweed
Readily available in several easy to use formulations
Provides the full range of trace minerals
Strengthens the immune system of plants, helping them to ward of diseases
Contains growth hormones that aid in photosynthesis and protein production
Rock Potash
Maintains its activity in the soil for long periods
Provides ample potassium, difficult to find in many organic fertilizers
Sewage Sludge
Gardeners can get it free or at low cost from municipality treatment plant
Work into the soil to reduce odors
Source:
Hamilton, G. (2004). Organic Gardening. DK Publishing, London.
The copyright of the article Choose an Organic Fertilizer in Organic Gardens is owned by Jamie McIntosh. Permission to republish Choose an Organic Fertilizer must be granted by the author in writing.