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DOs and DON’Ts of Fertilizing Your Organic Garden

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Do test Your Soil
The best-planned garden will not be successful if your soil doesn’t contain the proper nutrients in the correct proportions. Soil tests are important to determine if enhancements are needed in your garden. These tests include measures of pH, nutrients, organic matter, and salt content. The results are useful in determining if enhancements are needed and if so, the proper amendment mix for optimal results. You can purchase do-it-yourself testing kits or submit soil samples to your local cooperative extension office for a small fee. You can find the cooperative extension office in you state by visiting the USDA's website. The advantage of using an extension service is that they interpret the results for you.

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The pH level affects the rate at which fertilizers become soluble and can be absorbed by plants. Most garden crops grow best when the pH is slightly acidic, between 6.0 and 6.9.

Don’t Forget Your Vitamins
Fertilizer bags usually contain three numbers, the percentage of nitrogen (N), potassium (P) and potassium (K) included in the mixture. These numbers do not add up to one hundred percent because the remainder of the material in the package is inert.

Plants use nitrogen to grow leaves and stalks. If excess nitrogen is present, the plant will have soft tissue, be generally weak and susceptible to disease. There will be a flush of vegetative grown at flowering time, but flower and seed formation will be slowed. Blood meal, made from the dried blood created as a byproduct of animal processing at slaughterhouses contains high amounts of nitrogen.

Phosphorus helps plants bloom and enhances flowers color and fragrance. Poor growth often is the result of a phosphorus shortage. Bone meal, created from the sterilized bones of slaughterhouse animals, contains phosphates and calcium.

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From the Organic Authority Files

Potassium promotes strong stalks and stems and help roots to be come well developed. It is necessary for good tulips, gladiolas, dahlias, firm potatoes, juicy carrots, and beets. Excess potash results in watery plants that are unable to resist drought and have delayed maturity. Kelp meal, made from dried seaweed, contains potassium, amino acids and potash. Potash is the common name for potassium carbonate and other compounds that contain the element potassium in water-soluble form.

Don’t Over-do It
Too much of a good thing applies to fertilizer. So get your soil tested and see what you need before applying nutrients haphazardly. Don’t waste time, money and energy on unnecessary fertilizers.

Take this advice and you should have a successful gardening season. You’ll have done the right things to start off your garden with organic plants and improved your soil with the nutrients it is lacking.

Country Journal, “Planting Seeds”, March 1999, p.34.
Flower & Garden Magazine, “The nitty-gritty of soil tests”, Feb – March 1994, p.20.
Flower & Garden Magazine, “Why good gardeners soil test”, May 1984, p.54.
Garden Guides,, “Natural Garden Fertilizer Ingredients“
Mother Earth News, “Seed starting basics”, Dec 2005, p.64.
Mother Earth News, “Start your own seeds”, Dec 2001, p.52.

Maureen Farmer is a master gardener and has loved plants all her life. She enjoys growing most of her own produce in raised beds. She is the owner and founder of The Farmer’s Garden, a free surplus backyard produce trading service available across the United States.

Related Articles:
Maureen Farmer's 7 Easy Steps to Get Your Organic Garden Started
The Dirt on Fertilizer - Organics vs. Synthetics
Organic Gardening: Fertilization Tricks of the Trade

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