Fertilizer Types, Ingredients and Knowing What Your Plants Need
Imagine walking down the aisle at your local garden center. You’re in search of a good fertilizer for your garden. You turn down the aisle and realize that picking out a fertilizer isn’t as simple as you previously thought. There are a ton of options… organic fertilizers, plant-specific fertilizer, water-soluble fertilizers, slow-release fertilizer. With all the options available, how do you know that you’re choosing the right fertilizer?
In this article we’re answering some of your most common questions. Choosing the right fertilizer doesn’t have to be difficult.
What is Fertilizer?
Fertilizer is a compound that we can add to garden soil to keep them healthy. At its simplest, fertilizer is added to soil to provide a source of nutrients for plants. It’s important to realize that plants must absorb nutrients from the soil to grow and produce blooms, leaves or fruit.
These nutrients aren’t always replaced after they’ve been removed from the soil. Fertilizer is an easy way to add these nutrients back to the soil.
What Are the Two Types of Fertilizers?
You can group fertilizers into two main categories: fast-acting and slow-release. Fast-acting fertilizers are available to the plant more quickly. These fertilizers are often water soluble and can be picked up by the plants quickly. Slow-release fertilizers are often pelleted or encapsulated. This covering or coating prevents the fertilizer from being released rapidly and instead allows it to be released gradually, usually over a few months.
We recommend using a blend of both fast-acting and slow-release fertilizers for the best results. At the beginning of the growing season, apply a slow release fertilizer and work it into the soil. This will produce a steady supply of nutrients, so even if you forget to fertilize, your plants will be well-fed. Use a fast-acting fertilizer to feed your plants during periods of heavy production: when plants are moved or transplanted, blooming or producing fruit.
Both slow-release and fast-acting fertilizers can be purchased as organic or inorganic.
What Are the Three Main Ingredients in Fertilizer?
Most fertilizers contain the three nutrients that plants need in the largest amounts. These nutrients are called macronutrients. The three macronutrients for plants are nitrogen (N), phosphorus (P), and potassium (K). When you look at a bag of fertilizer, these three nutrients are often shown in what is called the NPK ratio. If you’ve ever wondered what the three numbers separated by hyphens on a bag of fertilizer are, it’s the NPK ratio.
On a bag of fertilizer, the three numbers represent the concentration of nitrogen, phosphorus and potassium, respectively. For example, a fertilizer with these numbers on the bag: 30-20-25, indicates that 30% of the fertilizer is nitrogen, 20% is phosphorus and 25% is potassium. You can use these numbers to find the ideal fertilizer for your plant.
If you’re looking for a well-rounded fertilizer, be sure to check the nutrition information on the bag for more information about other nutrients that are included in the fertilizer.
What Is the Difference Between a Vegetable Fertilizer and a Fertilizer for Flowers?
Vegetable plants and flowering plants have different nutritional requirements. All plants need the 16 essential nutrients. However, the amounts of each nutrient that plants need will be determined by their growth patterns and whether they bear fruit. Nitrogen, phosphorus, and potassium are involved in many processes in the plant, but the lack of one of these in adequate amounts will affect growth or development.
Nitrogen is the nutrient most often required in largest concentrations. Nitrogen is involved in leafy growth and development. All plants have leaves and therefore need nitrogen. Plants that have heavy leafy growth will require large amounts of nitrogen. For example, lettuce and leafy greens will need more nitrogen.
Phosphorus is involved in root development. Plants that have complex or highly developed roots will need higher concentrations of of phosphorus. Vegetable plants that are grown as root crops will need large amounts of phosphorus to produce a healthy crop.
Potassium is involved in proper bloom development. Without potassium, plants will drop blooms. Vegetable plants that produce vegetables from blossoms, like tomatoes, cucumbers, and peppers, need potassium to help promote healthy blooms.
The difference between vegetable and flower fertilizer has to do with the differences in the needs between the two groups of plants. Most flower fertilizers have a higher concentration of potassium to help promote healthy, beautiful blooms. Vegetable fertilizers often have higher concentrations of all three nutrients to ensure proper leafy growth, root, and bloom development.
Is Compost or Manure the Same as Fertilizer?
Fertilizer is often sold as a concentrated blend of nutrients. Compost and manure are not the same as fertilizer, but all three options can feed your plants. Compost and manure have become popular options lately for replacing conventional fertilizers. Compost and manure are created by recycling plant matter and animal waste. Plant matter and animal waste are full of nutrients. When these are turned into compost and manure, they are nutrient-rich alternatives to fertilizer.
Compost can be created at home. Consider all the food scraps, paper and eggshells that you toss into the trash each week. These scraps can be placed into a compost bin or a compost pile, creating a rich replacement for your fertilizer. If you have livestock or chickens at home, you can also use their manure and add it to the garden. If you don’t have livestock or haven’t started composting yet, you can buy bagged compost or manure.
Do I Need a Plant-specific Fertilizer?
You may have noticed that there are plant-specific fertilizers available. Some of the most common ones are for tomatoes and roses. Although these fertilizers aren’t necessary, they are a wonderful way to boost your plant’s health or production. Roses bushes that are fed with fertilizer developed for roses often have deeper colored blooms, stronger fragrances, and a higher number or blossoms. Tomatoes are heavy feeders, which means they will go through fertilizer and nutrients rapidly. Feeding your tomatoes with a tomato fertilizer can produce larger yields, more flavorful fruit and more resistance to pests and disease.
Plant-specific fertilizers can also have added benefits. For example, the Tomato-Tone fertilizer includes the nutrients that your tomatoes need to thrive and an added blend of beneficial microbes that will help the plant better absorb nutrients.
My Plants are Lacking One Specific Nutrient. How Do I Fertilize Them?
Most fertilizer are a blend of the most needed nutrients. Not all fertilizers contain all of the necessary nutrients. You may find that even with proper feeding, your plants aren’t getting adequate nutrients. This can be caused by many factors, ranging from using the wrong fertilizer to your soil’s natural composition. In either case, you can find fertilizers that will replace one specific nutrient.
A common nutrient deficiency seen in vegetable plants is calcium deficiency. This often shows itself as blossom end rot. Peppers, tomatoes, and squash can develop a dark, rotten end. This is due to a lack of calcium. To treat this common condition, you can purchase calcium foliar spray and spray the leaves and blooms of the plant. This isn’t going to fix the issue in the long term, but it will spare your plants from blossom end rot.
You can find fertilizers that are one nutrient fertilizers. Urea is a fertilizer that can be used to add nitrogen to the soil. You can also find superphosphate, which is a source of phosphorus. If you’re looking to add a specific nutrient to your soil, you can find a fertilizer to do that.
There are soil additives that you can use to add specific nutrients to your soil. If you notice year after year that you’re dealing with blossom end rot, you should add an additive to the soil to stave off calcium deficiencies. Calcium nitrate, gypsum and dolomite are good sources of calcium. Gardens that are frequently low in nitrogen may benefit from using nitrogen-fixing cover crops in the off season. Plants like beans, clover or alfalfa can add nitrogen back to the soil and can be tilled into the ground as green manure in the spring.
