Have you ever found yourself on the fertilizer aisle at your local garden center, trying to decide what type of garden fertilizer you need to use for your plants? There are so many options available that it can quickly overwhelm you if you don’t know what to choose. The wrong fertilizer can do more harm than good. Not only will the wrong fertilizer be unable to give your plant what it needs, it could actually harm your plant by creating toxicities. Let’s talk about how to choose the best fertilizer for your plants, every single time.
What’s in garden fertilizer?
Fertilizers are a blend of nutrients for plants. You probably know that your body needs specific nutrients to be healthy. You need nutrients to grow, replace old or cells, heal, fight off disease, digest food and so much more. Plants are the same way. They need a constant supply of nutrients to stay healthy. Plants will use their roots to pull nutrients out of the soil. Unless the soil has a way of replenishing the nutrients that the plants have pulled out, the soil will eventually become depleted of nutrients. When this happens, your plants will develop toxicities. If you’ve ever had vegetable plants with yellow leaves or dropped blooms and fruit, it could be from a lack of nutrients.
Garden fertilizers can be broad or they can be specific. They can be sourced with organic materials or synthetic ones. So how do you know which fertilizer is best to use?
You’ll want to use a fertilizer that provides the nutrients that your specific plants will need. The front of the fertilizer bag will give you a big clue as to whether a fertilizer blend is right for your plants or not. Plants have 16 nutrients that they need to be healthy. These nutrients can be found in fertilizers. The three most important nutrients are nitrogen, phosphorus and potassium. When you look at the front of a fertilizer container, you’ll see three numbers, separated with hyphens.
For example, the FoxFarm Happy Frog® Tomato & Vegetable Fertilizer bag has these numbers on the front- 5-7-3. These numbers let you know what percent of the fertilizer is nitrogen, phosphorus and potassium. The first number is nitrogen (N), the second represents phosphorus (P) and the third represents potassium (K). These numbers are commonly referred to as the NPK value.
Nitrogen is the most important nutrient for most plants because it’s needed in large amounts. Nitrogen helps to promote leaf growth especially, although it’s involved with numerous other parts of plant growth. Phosphorus is important for healthy flower production and root development. Potassium helps in many functions of plants, including fighting off disease or pests and staying healthy during drought.
Choosing the Right Garden Fertilizer
Now that you know a little bit about fertilizers and the nutrients in them, how do you choose a good fertilizer for your plants?
Do my plants have any deficiencies that I can identify? (Signs of deficiencies include slow growth, lost fruit or blooms, discolored leaves, etc.)
Will my plants produce blooms?
Are you growing leafy vegetables?
Do your vegetable plants produce both blooms and fruit?
Are you growing root vegetables?
Do your flowers have a bulb?
Are you growing organic?
It can be tempting to buy a general fertilizer, like Miracle Gro, and apply it to all of your plants. You’ll get the best results though if you buy a few tailored fertilizers to use with different plants rather than a broad spectrum fertilizer. If you’re growing organic, you’ll have just as many options for organic fertilizers as you will synthetic fertilizers. Simply choose a fertilizer that is organic and well-suited for your plants.
Best Fertilizer for Vegetable Plants
Most summer vegetable plants need to be fertilized in a way that will promote healthy leaf growth, while also supporting healthy bloom and fruit development. If you’re not careful, you could end up with a lush, beautiful tomato plant that doesn’t produce any tomatoes, or a cucumber plant that produces more cucumbers than the few leaves it has can support.
The Espoma Organic® Garden-tone® Herb & Vegetable Food fertilizer is perfect for growing healthy vegetable plants. The NPK value of this fertilizer is 3-4-4. The 3% nitrogen will help your vegetable and herb plants grow healthy leaves and support an overall vigorous plant. The 4% phosphorus will help promote healthy blooms, which leads to healthy fruit. 4% potassium helps to keep your plant healthy, no matter what kind of stresses it may have.
This fertilizer has a few extras that will help to keep your vegetable plants going strong. The Espoma Organic® Garden-tone® Herb & Vegetable Food also contains calcium. This helps to prevent blossom end rot, which is a common problem with many vegetables including tomatoes, peppers, and squash. You’ll also find magnesium and sulfur in this fertilizer, two more important nutrients that vegetable plants will need.
Lastly, this fertilizer contains beneficial microbes that help to keep your plant healthy. This fertilizer blend was originally developed for professional gardeners but is now available for all gardeners. Oh, and did we mention that this is an organic fertilizer as well?
For soils that are worked hard by vegetable plants, we recommend giving an extra boost of nutrients with the FoxFarm Happy Frog® Tomato & Vegetable Fertilizer. This fertilizer blend is similar to the Espoma Organic Garden-tone Herb & Vegetable Food blend, but with higher concentrations of nutrients. The NPK value of the FoxFarm fertilizer is 5-7-3. There is additional nitrogen and phosphorus to give your vegetable plants the nutrients they need to grow tons of vegetables. There’s also enough potassium to keep your plants healthy. This is also an organic option with beneficial soil microbes.
Tomatoes are the most commonly grown vegetable plant. You can find fertilizers specifically for growing tomatoes, which can really boost your crop yield. We offer three amazing options for tomato fertilizers. The first one option is the Tomato Fertilizer Spikes.
This is by far the easiest way to fertilize your tomatoes. Simply stick the spike into the soil near the plant and let it do the rest! The NPK value of this fertilizer is 8-24-8, so it’s packed with nutrients to produce high yields.
If you want to fertilize your tomato plants slowly and prefer to keep a closer eye on their nutrient intake, then check out the Espoma Organic® Tomato-tone® Tomato & Vegetable Food. This fertilizer blend has a lower NPK ratio of 3-4-6, so you won’t have to worry about burning your roots.
It also contains beneficial soil microbes. Looking for a liquid option? Check out the Espoma Organic® Tomato & Vegetable Food.
Best Fertilizers for Flowers
Flowering plants that don’t produce fruits and vegetables need nutrients targeted at healthy bloom development. You’ll see a difference in bloom quality and appearance when you fertilize your plants specifically for flowering. Park Seed has many options for quality fertilizers for flowering plants. Choose the best option based on the type of flowering plants you’re growing.
Roses are some of the most commonly grown flowering plants. Roses produce stunning blooms all summer long. The Jackson & Perkins® Dynamite™ Select Rose Fertilizer has an NPK value of 14-5-10. The higher values of nitrogen and potassium encourage maximum growth and bloom development.
This specialized fertilizer blend also contains trace minerals that help support rose formation like calcium 1%, magnesium 2.75%, sulfur 4.56%, iron 1%, manganese .80%, and zinc .06%.
If you want to grow roses and protect them from pests like aphids, Japanese beetles, thrips and borers, then choose a fertilizer that will both feed your roses and keep pests away. The Bonide Systemic Rose & Flower Care does both.
This fertilizer blend feeds your roses for maximum blooms with an NPK value of 8-12-4. It also contains an insecticide 0.22% imidachloprid, a revolutionary compound that gets absorbed in plants’ roots with the nutrients and protects the plant from the inside out for weeks, including everything from the roots to the new shoots of growth.
Flowers that grow from a bulb have unique nutritional needs. They need nutrients that will support healthy bloom development and root development at the same time. Since the plant is so dependent on the unique root structure in these plants, it’s important to fertilize the plant carefully to prevent root burn.
Root burn in a bulbing plant can kill the plant, preventing it from coming back year after year. The Espoma Organic® Bulb-tone® Bulb and Flower Food has a NPK value of 3-5-3 so that you can fertilize your sensitive bulb flowers without worrying about burning the bulb.
Like the other Espoma fertilizer blends, this blend contains beneficial soil microbes that help create a healthier plant.
This post was written by Shelby DeVore, the founder of Farminence. Shelby is a passionate gardener with 20+ years of experience gardening and growing food at home. She currently lives in West Tennessee on a 14-acre homestead with her husband, three children and too many animals to list.