Talking %^&* – Fertilizers

Plants need three things, sun (light), water and Nutrients. Nutrients come naturally from organic matter and elements in the soil. Nutrients will become depleted over time and will need to be replenished in the soil.

It is highly recommended you get your soil tested to see what your soil health is. Healthy soil creates a healthy plant. There are many self soil test kits available, and they are pretty in-expensive. A typical soil test tests for Nitrogen, Potassium and Phosphorous, as well as the Ph (acidity) of the soil and will give you a starting point for choosing fertilizers.

For plant growth, we tend to focus on the big three nutrients;

Nitrogen (N), Phosphorous (P) and Potassium (K).

Nitrogen (N) is essential for almost all aspects of plant growth and is the most used nutrient by plants.

Phosphorous (P)  strengthens the roots as well as seed/fruit production. It is also essential to photosynthesis. 

Potassium (K) is essential for roots and aids in fruiting, and essential to helping water move throughout the plant. 

The three-digit number (N-P-K ratio) on fertilizers represent Nitrogen – Phosphorous – Potassium in that order. The ratio gives you an indication of the nutrients present for use by the plant. 

10-15-20 = 10 percent nitrogen – 15 percent Phosphourous – 20 percent Potassium. 

Although Nitrogen is used throughout the plants’ life, it is essential for initial growth and expansion as it grows to maturity. The early season should see an increased need for Nitrogen in the soil and thus a nitrogen-rich fertilizer.

As the plant flowers and grows fruit, Phosphorous and Potassium are needed more, so an increase in the P and K ratio is in order.

Three other significant nutrients plants need are Sulphur, Calcium and Magnesium. These are considered micro-nutrients for plant growth.

Sulphur helps plants and crops resist disease, aids in seed creation (fruiting) and contributes to plant growth.
Calcium is needed to help plant cells develop, assist in disease resistance, and increase Nitrogen’s uptake into the plant.
Magnesium contributes to the “greening” and chlorophyll production in the plant.

Wheelbarrow with natural cattle manure on the grass

Organic Fertilizers

Composted manure has long been a source of nutrients for gardeners, but not all manure is created equal. All manure needs to be composted with no “smell”. Manure from different animals will produce varied NPK ratios as well as micro-nutrient content. Composted manure mixed pre or post gardening season directly into the soil should provide the nutrients for most gardens.

Cow manure is considered a Nitrogen-rich fertilizer with a 3-2-1 NPK ratio. It’s an excellent all-around fertilizer and can be applied anytime. It is the most commonly used manure.
Sheep Manure is higher in Phosphorous and Potassium, so it is an excellent addition for later stages and flowering/fruiting stages of its growth.
Chicken manure is very high in Nitrogen and contains a good amount of Potassium and Phosphorous as well. It is sought after for that fact. The high Nitrogen of the chicken manure could damage plants, so it must be composted thoroughly.

garden fertilizer on gardeners hand

In-Organic Fertilizers 

In-organic fertilizers are chemical fertilizers that have been created and contain very specific and consistent ratios of nutrients formulated for plant growth. These fertilizers are available in a wide range of concentrations and ratios, some are plant-specific, some are based on the stage of plant growth and others are general usage. Information on the specific uses for speciality fertilizers/ratios are usually documented on the package.

Pellet and liquid fertilizers all have an NPK ratio displayed and are much higher in essential nutrients than manures. A balanced fertilizer will have equal amounts of NPK (10-10-10). A 20-20-20 has the same ratio however has twice as much of each nutrient.

So what’s the correct NPK ratio for you? Well, it depends; I recommend getting your soil tested. That will tell you the deficiencies in your soil; If your soil is high in Phosphorous (common in the area), low in Potassium and moderate in Nitrogen, you could get something like 10-20-0. In most cases, manure or low NPK ratio fertilizers are suitable for most gardens. For more intense gardening like square foot gardening, I like to use a higher ratio fertilizer as the nutrients are used faster.

Micro-Nutrients

Micro-Nutrients are needed for plant growth. They may not be used by the plant as much as NPK; however, without the micro-nutrients, the plants will not grow well, if at all. Most micro-nutrients are available in most organic fertilizers as a natural product. You don’t need a lot of micro-nutrients; however, in intensive gardening, the micro-nutrients can become depleted over time.

Micro-nutrients, Sulphur, Calcium and Magnesium, can be found in some specialized fertilizers in varying amounts. Bone meal is an excellent source of Calcium.

Home Made fertilizer/Micro-Nutrient Solutions

A practical and inexpensive method of getting Calcium into your garden is eggshells. By saving your eggshells, baking them for 15-20 minutes and then grinding them up, you will create a perfect alternative to bone meal.

Magnesium is as easy as Epsom salts. Epsom salts are very high in magnesium, and they dissolve quickly in water. Sparingly spreading Epsom salts into the soil in the spring or even a light spray will replenish any depleted magnesium quickly. Tomatoes are highly susceptible to magnesium deficiency, significantly when grown in containers.

Another great use for coffee grounds is as a fertilizer. They contain a good amount of Nitrogen, Phosphorous and Potassium, as well as many micro-nutrients. Save your grounds and spread them in your garden.

Do your plants need a shot of Potassium? Bananas contain a large amount of Potassium. You can compost the peels; however, a more effective and quicker method is to place the peels in a jar with water for a week or so. This Banana peel tea will become highly concentrated in Potassium, which can be poured into the garden.

This article and many like it appear in the Nipigon Gazette and Terrace Bay Schreiber News. Subscriptions are available at nipigongazette@shaw.ca