Choose an Organic Fertilizer
Natural Plant Food Yields Healthy Lawns, Flowers, and Vegetables
Feb 19, 2008
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
Cottonseed Meal
- Contains all the major elements
- Releases nutrients slowly
- A good choice for feeding the organic lawn
Dried Animal Manures
- Contain all the trace elements
- Work well as a soil enrichment agent
Feather Meal
- Provides a slow release form of nitrogen
- Inexpensive, but not widely offered
Fish Meal
- Good source of nitrogen and phosphorus
- 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.
