Updated March 8, 2022 by Mark Marino
Indoor houseplants, whether tropical plants, flowering plants, or any types of foliage plants grown in your home, have no access to nutrients other than what’s contained in their potting soil when you plant them and what you feed to them in the form of granular fertilizers, liquid fertilizers, or organic fertilizers. Most plants that are grown in your garden obtain their nutrients from your garden soil. While outdoor plants can benefit from periodic organic fertilizer or synthetic fertilizer, indoor plants rely on it for optimum health. Here, we’ll explore the ins and outs of houseplant fertilizers and how often to use them.
How Often Should I Fertilize My Indoor Plants?
Fertilizing too much or too little is problematic for your indoor plants. Most plants can benefit from some fertilizer, but it’s crucial to get the amount right. Too little fertilizer can lead to weak plants while too much can cause problems like brown leaf tips, which are emblematic of fertilizer burn. Unfortunately, it’s not always easy to determine when to fertilize your indoor plants because it might be anywhere from every other week to once every four months, depending on the type of product you use. It’s crucial to find out about your specific indoor plants and their nutrient needs in order to pick an appropriate product for them. Also, it’s important to read the labels of your fertilizer product and follow them as directed.
When to Fertilize Houseplants
Different houseplants have different needs when it comes to fertilizer. While it’s often easy to tell when to water your indoor plants because their leaves will droop or may even appear to be dried out, it’s not so easy to tell when your indoor plants need to be fed. Garden experts typically suggest forgoing houseplant fertilizers during the winter months when the plants become dormant. Most indoor plants only need to be fertilized during their active growing season.
If you’re unsure when to feed houseplants, you can rely on a few signs such as:
- Stunted growth of plants
- Discolored foliage
- Unusually small blooms from your flowering houseplants
- Delayed blooming of plants
On the other hand, these signs may not be present at all. Instead, it’s better to fertilize houseplants according to a schedule. Again, the time frame will necessarily depend on the specific needs of your plants and the type of fertilizer you choose, but generally speaking, your indoor plant care fertilizer routine might look something like:
- Begin to fertilize houseplants two months before the last expected frost. Even though these are indoor plants, they still respond to seasonal cues like the lengthening of days.
- When you fertilize houseplants at this time, opt for half-strength doses because the plants are only beginning to come out of dormancy; they are not in their active growth phase yet.
Your summer fertilization routine depends on the type of houseplant fertilizers you use. We’ll spend more time talking about the types of houseplant fertilizers later in this article.
- Liquid Fertilizers: a liquid fertilizer is associated with more frequent fertilization. Plan to fertilize houseplants with liquid fertilizers on a bi-weekly or monthly basis.
- Granular Fertilizers: these fertilizers require less frequent use. Fertilize your indoor plants using granular fertilizers every month or two.
- Slow Release Fertilizer: you can feed houseplants slow release fertilizer every three to four months.
- Begin to taper off your use of fertilizers about two months before the first expected frost. At this point, your plants are moving past their growing season toward the dormant winter period. You are unlikely to see any new growth so fertilization will prove less and less necessary as you head toward winter.
How to Fertilize Your Indoor Plants
How you fertilize plants depends on the types of fertilizers you choose to offer your plants. Essentially, you will simply follow the instructions on the labels of your fertilizer products. On the other hand, if you are using organic fertilizer or compost to feed houseplants, you may only need to apply it once or twice. In fact, if you choose a worm compost, which works well in conjunction with a plant’s roots, you only need to apply it to your plant’s soil once during the spring to create a healthy soil biome. To determine how often to apply organic fertilizers, you’ll need to consider what nutrients the ingredients contain and how much of those nutrients your plants need to thrive.
Types of Indoor Fertilizers
As mentioned, there are different types of fertilizers you can use to feed houseplants. These include:
Liquid fertilizers are easy to use providing you remember to use them. They’re associated with more frequent use. To apply these fertilizers to your indoor plants, simply dilute the fertilizer in water and then water the soil in your plant’s pot.
Granular fertilizer is sold, you guessed it, in granules or, rather, dry pellets. Although popular and inexpensive, granular fertilizers may work better for outdoor plants because they will ‘dump’ all their nutrients into the soil when you water your plant. This has the potential for offering too much chemical fertilizer to your plants. When it comes to fertilizer, less is better than more.
Organic fertilizers are made from natural sources such as plant, animal, and rock and mineral sources. These materials contain essential elements plants need to thrive. The plant and animal organic fertilizers may also contain helpful fungi and good bacteria that enrich the soil.
Slow Release Fertilizers
Slow-release fertilizer has become a popular option among gardeners for both outdoor and indoor plants. These types of houseplant fertilizers are easy to use. The fertilizer is contained in coated shells that slowly leech into the potting soil over time. For this reason, there’s less risk of over-fertilizing your plants. One application of these houseplant fertilizers is typically good for about four months; some products may last even longer.
Feed Houseplants to Avoid Nutrient Deficiency
Plants have nutrient needs just like other living things do. Just like too much water can cause root rot and too little water will cause plants to crisp, too much or too little fertilizer can also negatively affect the health of your plants. The key is to carefully follow the directions of your houseplant fertilizers. Use this guide to help you provide your indoor plants with the essential elements they need to support good health.