Among other things, watering, light, soil, and fertilizing are all the basic tasks in growing indoor and outdoor plants.
In this post we will discuss the role of houseplant fertilizer in keeping your indoor and outdoor plants healthy.
We’ll also take a look as to why you need to add houseplant fertilizer and when and how. In the following article, we’ll take a look at how and when you should feed your houseplants.
Table of Contents
- 1 Why Fertilize Houseplants?
- 2 When to Fertilize Houseplants?
- 3 Active Ingredients in Houseplant Fertilizer
- 4 Types of fertilizers
- 5 Conclusion
- 6 References
Why Fertilize Houseplants?
One of the reasons why you should be feeding your houseplants is because, like any other living thing, they do get hungry.
This is especially if they’ve been in the same potting soil for a while. Over time, watering eradicates nutrients, and since the plants are in containers, they cannot spread their roots for more indoor plant food
Signs of distress include stunted growth, yellow leaves, chlorosis, which is yellowing in the leaf veins. So to avoid this from happening, fertilize indoor plants to give your plants a boost.
However, before doing this, check to see that the problem isn’t to do with something else like a disease, insects, or improper watering.
Once you eliminate the other possibilities, you can go ahead and get your plants back on the road to good health using fertilizer.
The first three fertilizer attempts should be made at half the recommended strength. Use half the amount suggest on the label, especially if it’s a granular product.
If it’s a liquid plant fertilizer, mix it at half the strength.
This ultimately feeds houseplants at a time when they are starting to gear up for active growth, and they don’t yet need large amounts of nutrients to fuel healthy and prolific growth.
When to Fertilize Houseplants?
In most cases, feeding houseplant can be just once a year. is limited to just once a year.
However, this rule is often broken. Too much fertilizer weakens the plants, and any additional growth is likely to be stunted, and this is ultimately something that you’re trying to avoid.
So while there are different opinions about when to feed potted plants, the rule of thumb is that they should be fed minimally as possible.
One of the methods to feed indoor plants is called fertigation.
It is a method where a certain amount of food is included in the watering system. It is recommended to be done once a month.
The idea is to feed indoor plants during their growing season.
If you’ve got a second going through intent, give it fertilizer treating that time.
However, if your indoor plants are experiencing stunted growth or looking weak, then fertilizing them again in early summer may perk them up.
Do some research into the type of plant you have to learn how to take better care of them.
When it comes to fertilizing different types of houseplants, it’s hard to generalize because it varies from species to species.
So, as a rule of thumb, you should fertilize them in early spring when growth begins to pick back up.
Summer is a good time as well. However, if you have species dormant during the winter, then you shouldn’t bother to fertilize them in this time.
You should only have to fertilize your plants a few times a year sp space it out by a month or so during the growing seasons.
Another important note is that you should never fertilize them when the soil is dry as it could cause your plant to be burned.
Instead, mix the fertilizer into the water before watering your plants or add them in after you have already watered.
Active Ingredients in Houseplant Fertilizer
Household fertilizers usually contain a mixture of macro and micronutrients.
The three primary macronutrients are nitrogen, potassium, and phosphorus that are found in a container of fertilizer and listed as a ratio on the front of the bottle or bag.
Consequently, the ratio of these macronutrients in a tomato fertilizer or lawn fertilizer will be different than the ratio found in a house plant fertilizer since each of these groups has different nutritional requirements.
Therefore, you should specifically use a fertilizer that is formulated for house plants. And this should be the first thing that you look for in a house plant fertilizer.
So take a look at the packaging at the front or back, and it should say “for houseplants” somewhere on the bottle. Phosphorus is also essential for flowering.
Therefore houseplant fertilizer for flowering plants should have a slightly higher amount of phosphorus included in the ingredient list.
However, the houseplants that don’t produce flowers should have a higher concentration of nitrogen. They should also contain a bit of each of these nutrients.
So typically, you should use one house plant fertilizer for your flowering plants and a separate one for non-flowering plants. Lots of fertilizers also contain secondary macronutrients such as magnesium and calcium.
They may also contain micronutrients such as zinc, iron, and boron. Ultimately, you need to be sure that your house plant fertilizer contains even a small amount of these nutrients.
Types of fertilizers
Liquid Houseplant Fertilizer
Liquid houseplant fertilizers need to be used more frequently than granular fertilizers; however, organic fertilizers seem to be quite popular amongst gardeners.
Most liquid plant food contain ingredients derived from plants and animals as well as mined minerals.
Liquid fertilizers come with a decreased risk of fertilizer burn.
Another bonus of using fertilizers made from naturally occurring ingredients is that they also act as growth enhancers in addition to providing your house plant with nutrients.
Liquid fertilizers have dozens of micronutrients, vitamins, amino acids, trace elements, and plant hormones, each of which plays a vital role in the health of your house plants.
Solid (or Granular)
Granular houseplant fertilizer (or solid fertilizers) are found in two specific types, which are granular pellets or compressed fertilizer spikes.
The pelletized granular fertilizer is sprinkled on the surface of the soil. The compressed fertilizer spikes are pushed into the soil to come into close contact with the plant roots.
The best of these granular solid house plant fertilizers are made from naturally derived ingredients.
This includes dehydrated worm castings, blood meal, sulfate of potash, bone meal, rock phosphate, limestone, and animal, mineral, and plant-based ingredients.
Synthetic or chemical-based granular fertilizer is also available for houseplants.
However, if you are more into using organic fertilizers, then you should avoid them.
One way to tell a synthetic fertilizer apart from an organic one is that the synthetic fertilizer will not contain an ingredient list at all.
Liquid Organic Houseplant Fertilizer
Organic fertilizers are plant food that is made from ingredients such as fish emulsion, liquid kelp, compost tea, bonemeal, plant extracts, rock phosphate as well as human acids, to name a few.
The bonus is that you don’t need to go out and buy organic fertilizers because you can create your own. In nature, the decomposition of organic matter will create a natural fertilizer.
Ultimately, these natural ingredients that can be decomposed into the soil improve the quality and texture of the soil as well.
It also increases the soil’s ability to hold water, reduces erosion from wind and water, and decreases compaction and crusting of the soil, all while raising the soil’s pH.
This indoor plant fertilizer is also known as time-released fertilizers. They are made from a synthetic source of nutrients, and the nutrients are encapsulated in a coating.
Ultimately, this coating breaks down slowly and releases in low doses over a long period of time.
So what it actually means from a practical point of view is that you will be fertilizing your plants less frequently.
So that’s convenient; however, one of the drawbacks is that they’re not made from eco-friendly ingredients.
Houseplant fertilizer myths
There are lots of myths surrounding fertilizers, such as mineral fertilizers are not natural.
So it’s important to distinguish what is meant by organic and mineral, natural and synthetic. Organic fertilizers contain carbon.
Some are natural such as manure, and others are synthetic such as compost.
Mineral fertilizers, on the other hand, maybe organic and can be synthetic such as man-made fertilizers like urea.
However, they can also occur naturally in the environment, such as phosphate rock and potassium chloride.
Another common perception is that mineral fertilizers poison the soil, and this, of course, is not true; however, the excessive rates of mineral or organic fertilizers can cause severe environmental damage.
It’s also another common misconception that fertilizers deplete the soil of organic matter. However, according to scientists, mineral fertilizers actually increase crop biomass.
So as you can see, using organic fertilizers may work in some areas where the land is already nutrient-rich. And in most cases, this is a product of decades of mineral fertilization.
In areas with poor or depleted nutrients, such as sub-Saharan Africa, it’s not practical or wise to rely solely on organic farming.
Provided you use fertilizer correctly, it’s quite a simple and affordable way to get the best out of your plants.
There are lots of fertilizer options available to feed houseplants.
Which means you can be as picky as you want, choosing a fertilizer and feeding schedule that perfectly suits both you and your plants.
Specialist blend and synthetic fertilizers can always be purchased by house plant growers and gardeners who know in-depth what their plants require.
Whereas casual house plant owners can keep things simple by selecting a general all-purpose plant food, plant food spikes, or a smart release plant food.
Ultimately, it helps to improve the health and growth of most indoor houseplants, including tropical plants, without making things complicated.
Provided how simple fertilizers are to use, the upside of healthy growth, there is no reason not to use them.
- Erler, E. (2018). Fertilizing Houseplants. University of New Hampshire Cooperative Extension.
- University of Maryland Extension. (2021). Fertilizer for Indoor Plants. University of Maryland, College of Agriculture and Natural Resources.
- UConn Home and Garden Education Center. (2016). Houseplant Fertilization. University of Connecticut Home & Garden Education Center Perennials Guide
Lindsey Hyland grew up in Arizona where she studied at the University of Arizona’s Controlled Environment Agriculture Center. She continued her gardening education by working on organic farms in both rural and urban settings. She started UrbanOrganicYield.com to share gardening tips and tactics. She’s happy to talk about succulents and houseplants or vegetables and herbs – or just about anything in a backyard garden or hydroponics garden.