Organic Fertilizing: Healthy Soils = Healthy Plants


Question From a Gardener: I’m an organic gardener in the western Rocky Mountains and realize that all mountain gardens are lacking nitrogen. I would rather not use chemical fertilizers and wonder how to solve this dilemma using organic fertilizing. What’s the best way to do this?

Answer: You’re correct in your assessment of Rocky Mountain soils. They are rich in minerals because so much of our soil started out as rocks which are composed of minerals like phosphorus, potassium, calcium and magnesium. But our soils are also the remains of the sedimentations left from the mountain building periods of volcanoes and earthquakes. These sedimentations are devoid of organic materials and nitrogen or iron which is the necessary ingredient for rapid, greener growth that we like in our lawns.

Organic fertilizers are also soil conditioners that improve the soil as well as feed the plants. These fertilizers are the composts, manures and mulches that add beneficial bacteria to the soil. Organic fertilizers are non-burning and slow feeding and also include dried alfalfa pellets, bone meal, coffee grounds, grass clippings, peat moss and worm castings. It’s interesting that lightening is also an excellent organic fertilizer. Note: Manures often contain excessive amounts of salts so go easy on manures since Western soils are typically salty.

Chemical fertilizers contain mineral salts that furnish a “quick fix” for plants. The salts do not provide a food source for the important soil microorganisms and earthworms, and over time the soil will lose the living organisms that are found in quality soil. Eventually, soil will require increasing amounts of chemicals to stimulate growth as soil structure and water-holding capacity declines. The positive side of chemical fertilizers is that they are easy to broadcast, but must have moisture to activate and will burn both plants and roots without being watered in.

Nitrogen is the most important ingredient needed in high mountain gardens because our soils suffer from an iron deficiency. Lack of iron causes iron chlorosis which usually occurs in alkaline soils and the fine particles of clay soil. Nitrogen is always the first number on a bag of fertilizer and in the west should be the highest number when purchasing fertilizers. The pros and cons of which fertilizer to use are the choice of the gardener after getting the results of a standard soil test but never exceed the average recommended one-pound of nitrogen per one-thousand square feet of gardens per year, for in chemical fertilizers, less is better.

Recommended Methods of Organic Fertilizing

Bacterial Compost:

When thinking about organic fertilizing, start by thinking about how Mother Nature fertilizes. The most common form is compost. When leaves fall off from leaves or plants, those leaves decompose, becoming new soil. Take all of the scraps from your garden and compost them to make further nutrition for your garden, or visit a local green waste facility to purchase compost that has been created using organic matter from other people’s yards and gardens.

Fungal-dominated compost:

You need a balance of bacterial and fungal compost in your garden. Fungal-dominated compost is created using wood chips and time, or a fungal source such as mushrooms to break them down. It can be purchased commercially.

Worm Castings:

Worm-castings are the waste that worms create when they chew through the compost in your garden that could include everything from fruit and vegetable scraps to grass clippings. You can purchase worm castings commercially, or if you are a particularly devoted organic gardener, you can even create a worm bed in your garage or laundry room and produce your own worm castings.

Earthworm castings - organic fertilizing
Photo: Wikimedia Commons

Other Organic Fertilizer Options

A healthy soil will be full of microorganisms and microbes. Create a compost tea to add them back into your soil. Dried alfalfa pellets, bone meal, coffee grounds, grass clippings, and peat moss are all good organic fertilizing options.

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