Fertilizer spikes are a convenient and easy way to fertilize your plants and improve soil quality over time. They come in various options to suit all your plant’s needs and are especially useful because they last for a long time.
You can break up fertilizer spikes before use and use them a bit at a time. However, different spikes are available for different plants, and you can use as many as required instead of breaking them up. You might consider crushing the spikes and broadcasting them for an even fertilizer application.
In this article, I’ll explain what fertilizer spikes are, how you can use them, and how you can work around the disadvantages of spikes by using them differently, so read on!
What Are Fertilizer Spikes?
Fertilizer spikes, also known as plant food spikes, are compressed fertilizers that can be used to feed plants the nutrients they need.
These plant food spikes are slow-release fertilizer that is not entirely water-soluble. Fertilizer spikes release their nutrients into the soil incrementally, depending on microbial action, soil pH, and temperature.
The spikes have a lot of nutrition packed in, released in small amounts into the soil. This consistent availability of the macro and micro plant nutrients in small quantities helps plants grow evenly. Plants that grow steadily are healthier, without the dangers of shooting up too quickly, like being fragile and susceptible to pests and diseases.
Applying too much fertilizer at once, especially inorganic, fast-release fertilizers, can cause fertilizer burn. Fertilizer burn is caused when the mineral salts in inorganic fertilizers accumulate and draw out the moisture from plant tissues. Fertilizer burn leads to dehydration, yellowing, and browning of roots and leaves and delays yields until plants have recovered.
Fertilizer spikes or plant food spikes are a great way to avoid fertilizer burn as they only release the nutrients in small quantities, which is just enough for plants to grow. Since they are released with microbial activity, these spikes attract organisms to the soil, which improves soil health in the long term, making your plants healthier.
There are different kinds of fertilizer spikes with different formulations, which takes the work out of determining what ratio of macronutrients you need for your plants. You can get plant food spikes for indoor and outdoor plants formulated to meet their specific needs.
Plant food spikes are typically more expensive than other fertilizers because they are concentrated and last anything between a month and six months. Unlike other inorganic fertilizers, spikes can be used throughout the year, which helps keep plants healthy through their dormancy.
Using Fertilizer Spikes on Indoor and Outdoor Plants
Plant food spikes can fertilize both indoor and outdoor plants, and you can decide which ones to use based on their description.
Spikes are formulated for plants, shrubs, and trees separately, as each of these will require a different concentration of nitrogen, phosphorus, potassium, and micronutrients. Depending on the type of plant, growth status, and where they’re grown, you’ll need to calculate how many of the spikes you need to place into the ground.
How Long Do They Feed Your Potted Plants?
Fertilizer spikes are favored by hobbyists and home gardeners alike because they are so easy to use and come in so many formulations.
You can use fertilizer spikes in potted plants, and they feed your plants for up to 60 days. The spikes are placed into the ground, which releases nutrients directly to the roots, reducing the time taken for fertilizer to disperse to the root hairs.
Consider Breaking Them up to Avoid Fertilizer Burn
You can use too many fertilizer spikes as with all fertilizers except organic fertilizers like compost. No matter how slow-release fertilizer is, you will burn your plants with excess fertilizer if you use too much.
Potted plants are particularly susceptible to fertilizer burn, even if you’re using plant food spikes, because they only have as much soil as is available in the pot. The limited space makes it easier for fertilizer salts to accumulate in the soil and cause fertilizer burn.
Using as much as or less than the recommended amount on the packaging is a general rule of thumb when using fertilizers. You might consider breaking up the fertilizer spikes before use when it comes to potted plants.
However, one of the disadvantages of plant food spikes is that you won’t be able to tell when the nutrients are being released.
Try to assess how much of the spike you’re using, so you have an estimate of how long it will last inside the pot. For instance, if you’re using half of a fertilizer spike that lasts for 60 days, then they might last about 30 days in your pot. After 30 days, water your plants thoroughly, and refresh your plants with more potting soil before you add more spikes to your plants.
Here’s a step by step guide to using fertilizer spikes effectively:
Identify the Right Spikes for Your Plants
First, identify the right plant food spikes for your needs. Different plants will need different ratios of nutrients and will need them in different quantities at different times.
For example, tomato plants usually need more phosphorus when they’re flowering and more potassium when they’re fruiting. Adding too much nitrogen at this point can burn them, so make sure you get the right spikes for your needs.
Determine if Its Growing Season
The growing season is when plants use up a larger quantity of nutrients, particularly nitrogen, as they grow taller. For most plants, the growing season is during spring. You might need to add spikes more frequently to your plants during this time.
Calculate How Many You Need
You’ll have to calculate the number of plant food spikes you need depending on the size and type of plants you have. You’ll need about one spike for every foot of height. You’d use several spikes along one foot of a row for vegetables – about 6-8 spikes per foot (0.3 m).
When in doubt, follow the package instructions.
Break up the Spikes
You should break up your spikes if you’re worried about fertilizer burn. It’s easier to add more fertilizer than to help a plant recover from fertilizer burn.
For plants with fragile root systems or plants in limited soil like potted plants, break up the spikes and use less than the recommended quantity.
Decide Where to Put Them
Fertilizers are never applied right at the base of the plant to prevent fertilizer burn. Ideally, fertilizer spikes should be placed a little distance away from the stem or the trunk of your plant.
For potted plants, you can place the spikes about half between the stem of the plant and the edge of the pot.
Water the Ground or Pot Thoroughly
Watering the soil thoroughly before fertilization makes the ground more malleable and hydrates your plant. This will prevent any immediate fertilizer burn, as the plants have enough water to hold up to the mineral salts released.
Dig In and Place or Hammer Them
To place the spikes, you can dig holes into the soil and place the spikes in, or hammer the spikes in. Most people choose to hammer the spikes in, especially for trees and shrubs rooted in the garden soil.
Drawbacks: Uneven Fertilization and Too Slow Nutrients Release
Fertilizer spikes are best used in the way directed on the packaging, but they do have some disadvantages.
Here, I will list out two of the main ones and how you can adjust the way you use your fertilizer spikes to work around these disadvantages:
They Don’t Fertilize Evenly
Since fertilizer spikes are compressed sticks planted at specific points around the plant, they release fertilizer only at those points. The roots of the plants grow unevenly as the plant concentrates root growth at these points where the nutrients are released.
To work around this, you might want to break up or crush your fertilizer spikes and broadcast them evenly across the soil. You could choose to just topdress your soil with the crushed spikes. However, if you want to keep the advantage of the spikes releasing nutrients close to the roots, you can incorporate the spikes into the soil.
They Release Nutrients Too Slowly
Slow-release fertilizers have their uses, but if you want your plants to grow quickly, then they may not be the best option. However, if you find yourself stuck with a bunch of fertilizer spikes and need a quick-release fertilizer, you can put your fertilizer spikes in water.
They’ll take a while to dissolve and will need to be diluted heavily before use, but this homemade liquid fertilizer is useful in a pinch. The liquid medium will make the nutrients more accessible to your plants and help them receive the nutrients faster.
You can break up fertilizer spikes before use, and it is a good idea to do so for potted plants or to distribute your fertilizer more evenly through the soil. For the most part, simply using the spikes as they are doesn’t have any ill effects on your plants.
You can get the exact formulation and concentration of fertilizers you need for your plants easily.