Building a better garden starts with a good nutrient regimen, and supplying your plants with an organic fertilizer is less of a hassle than you might think. If the words composting and manure just popped into your mind, followed by a delicate shudder, relax. There are many ways to supply your plants with natural nutrients, and many great products are available at your local hydro shop. A little basic information will take you a long way.
Why Switch to Organic Gardening?
There’s a big difference between organic and chemical fertilizers. Organic fertilizers come from plants and animals, often having undergone a natural process of decomposition that involves the activity of beneficial bacteria and insects. Organic fertilizers contain essential plant nutrients as well as abundant amounts of micronutrients.
Chemical fertilizers are inorganic, and their recipes are targeted to supply the essential elements plants need most, including the N-P-K on fertilizer labels (nitrogen, phosphorus and potassium). They can be formulated from a number of ingredients, including petroleum derivatives, and may or may not contain micronutrients. Unlike organic fertilizers that become water-soluble and available to plants gradually, chemical fertilizers are immediately available to plant roots.
In addition to providing nutrition, organic fertilizers also replenish the soil by increasing its porosity and oxygen content, and by supporting a rich network of beneficial micro-organisms. Chemical fertilizers feed plants, but organic fertilizers feed gardens.
Organic Fertilizer Products
There are lots of organic fertilizer products on the market. Some are designed to provide a few of the essential components plants need, while others are sold as complete fertilizers. Let’s take a look at some popular ingredients used by organic gardeners:
Blood Meal – A by-product of food processing, blood meal is animal blood that has been sterilized, dried and powdered. It adds easy-access nitrogen to the soil, which can be beneficial for depleted soils or for early spring planting when soil organisms are just becoming active. Without proper caution, blood meal can burn plants. It has an N-P-K rating of 12-0-0.
Bone Meal – Used as a source of phosphorus, bone meal is made of powdered bone matter, a by-product of food processing. It is safe to use and typically has an N-P-K of 3-15-0.
Corn Gluten Meal – A slow-release nitrogen fertilizer, corn gluten meal has an N-P-K of 9-0-0. Before it has a chance to completely decompose, which will take up to four months, this product may prevent seed germination.
Cottonseed Meal – A cotton industry by-product, cottonseed meal is a slow-release fertilizer that provides nitrogen and phosphorus. It has an N-P-K rating of 6-0.4-1.5. It’s on the acidic side, and is often recommended as a turf and acid-loving plant food.
Feather Meal – Another by-product of the food processing industry, feather meal is made from ground-up bird feathers. It’s a surprisingly good source of slow-release nitrogen at 7-12%.
Fish Emulsion – Made from heat and pH-treated fish waste, liquid fish emulsion is packed with micronutrients and offers an N-P-K of 5-2-2. This product is typically mixed with water. Although some gardeners prefer it, fish emulsion usually has an unappealing smell.
Fish Meal – Made from heat-sterilized fish waste, solid fish meal is a good source of nitrogen, with an N-P-K of 10-6-2.
Kelp – Seawater contains many of the dissolved micronutrients plants need. More than 70 known micronutrients are present in ocean water. Because kelp grows in this rich environment, kelp fertilizer delivers a boatload of micronutrients to plants. It contains negligible concentrations of macronutrients and is available in liquid and powdered form.
Manure – Animal waste is considered a slow-release fertilizer with multiple benefits. Nutrient concentrations in manure can vary, and may be difficult to quantify. With the exception of dog and cat waste, most types of manure can be added to the garden. This includes manure from cows, chickens, horses and sheep.
There are also household additives that can feed plants. They include:
Epsom Salt – A good source of magnesium and sulfur.
Molasses – Blackstrap molasses contains magnesium, potassium, sulfur, calcium and iron, as well as other micronutrients. You may have it in your kitchen to use in your baking, but it’s also available as a plant additive.
Wood Ash – Wood ash from fireplace wood (not pressed logs or coal ash) is a good source of potassium.
You may think there’s a big difference between fertilizer and compost, but that’s not necessarily the case. Both can provide nutrients to hungry plants. While composting has often been consigned to the role of soil conditioner, it can be a powerful source of plant nutrition, too.
Vermicomposting is an excellent example. If you haven’t heard this term before, it refers to composting using worms. Household and other kitchen waste is eaten by the worms and comes out as castings, or worm poop. Worm manure is considered one of the most natural and beneficial organic fertilizers around.
Worm castings are available by the bag at your local hydro shop, or you can create a vermicomposting set-up pretty easily either indoors or outdoors, and the process is fun and a great way to introduce kids to the wonderful world of friendly garden critters. Worms, often red wigglers, and composting bins can be picked up at a garden store. A quick online search will also yield extensive directions for vermicomposting DIYers.
Nature recycles through decay. It’s the process of breaking down one thing to turn it into something else. Composting is just a technique that speeds up the process a little by introducing heat. The trick to composting, whether it’s in a fancy rotary bin or in a pile on the ground, is to choose the right ingredients and use them in balanced proportions.
In return, the compost supplies the garden with macro- and micronutrients as well as soil conditioners. Ingredients like grass clippings (nitrogen), coffee grounds (phosphorus), banana peels (potassium) and eggshells (calcium) provide plant nutrition the way nature intended.
A compost pile needs organic matter, air and water to work its magic. It’s like setting the table for a banquet. If you have food, they will come. The “they” in this case are billions of critters in the form of bacteria, fungi and macro-organisms like worms and millipedes. You don’t need to buy them, they’re everywhere in an average garden, and adding good ingredients to a compost heap is like ringing the dinner bell.
To work well, the volume of organic matter in a compost pile has to be large enough to produce heat as the organisms break down the chemical bonds in the composted material. The internal temperature of an active compost pile can reach 150°F, indicating some serious biological activity is underway.
The high heat hastens decomposition, and has the side benefit of killing weed seeds and discouraging larger pests. That’s why pre-fabricated compost containers usually have a capacity of at least one cubic yard.
A compost pile contains two high-level ingredients: carbon and nitrogen. Carbon is energy food for the bacteria, and nitrogen delivers the protein necessary for growth and maintenance. If you provide these two ingredients in relatively equal quantities by volume, you won’t have problems. This may seem complicated, but it’s really not if you remember the color rule:
Green (nitrogen): Nitrogen-rich ingredients are green, like grass and freshly pulled weeds.
Brown (carbon): Carbon-rich ingredients are brown and relatively dry, like dead leaves and straw.
Other: Household compostables vary, but tend toward the carbon-rich end of the scale. When in doubt, guess carbon.
Beyond these essentials, a healthy compost pile needs to remain moist, but not wet, and loose enough to encourage good airflow. How long will you have to wait for fresh, nutritious compost? The timing will vary based on the size of the compost pile, its surface area and its specific ingredients. Turning the pile often, such as once every couple of weeks or so, helps speed up the process.
Best Types of Cover Crops
Some plants produce more nitrogen than they use, which can be a bonanza for your soil. One creative way to fertilize a garden is to plant these varieties, often as early spring or autumn crops, and then turn them under before planting vegetables, herbs or flowers in their place.
Green manure crops also help with soil conditioning and even control weed growth by crowding out undesirables. It doesn’t get much better than that. Crimson clover, an annual, is a popular green manure, but there are many others.
Now is the time to start planning your spring garden. Make this the year you decide a more organic approach to feeding your plants is the right approach.