There are a lot of things to remember when you’re a houseplant parent! It’s surprising to learn that houseplants don’t cry when hungry or uncomfortable, unlike human babies. Their responses to their environment differ greatly from ours, and are far more subtle. No matter how long you’ve been growing house plants, it can be challenging to know when to feed them. I would like to take the time today to explain the basics of houseplant fertilizer and tell you when and how to feed your houseplants.
When to feed houseplants
In the absence of water, houseplants wilt. Their leaves grow lean and pale when they are exposed to little sunlight. A low humidity can make them crispy, whereas a high humidity will cause them to rot. It is much harder to know when your houseplants need to be fertilized. Your plant doesn’t give you any clear signals that it’s time to eat. It is unlikely that they will notice any significant changes, other than perhaps slowed or stagnant growth, which is not uncommon for houseplant parents. To avoid waiting for the plants to give you a signal about fertilization, you’ll have to take matters into your own hands and use houseplant fertilizer on a schedule that matches their growth cycle.
While each houseplant may have slightly different requirements when it comes to fertilizer amounts and frequency, it’s not necessary for the process to be overly complicated. While you could do your best to learn about the specific nutritional requirements of each species of houseplant you care for, the vast majority of common houseplants have fertilizer requirements that are comparable enough that treating them the same way will more than suffice. It’s true that some houseplants are heavier feeders than others. Nevertheless, a houseplant fertilizer schedule such as the one found below provides a good balance that satisfies both heavy feeders and those houseplants that don’t require excessive amounts of fertilizer.
The following fertilizer schedule is recommended for most common houseplants. It is a result of the changing seasons, which, even though houseplants grow indoors where temperatures are more consistent, are impacted by the same rhythm that affects outside plants.
The best houseplant fertilizer schedule
The following is a brief overview of different houseplant fertilizer products mentioned here and how they are used, but here’s when these products should be used.
Spring houseplant fertilizer schedule
- Start fertilizing houseplants about 8 weeks before the last expected spring frost. For example, in Pennsylvania, the danger of spring frost typically passes by May 15th. As a result, I fertilize my houseplants beginning in mid-March. At this time, the days begin to lengthen and houseplants transition from a semi-dormant state to one of active growth.
- The first three fertilizer applications should be made at half the recommended strength. A granular product should be used half as much as the label suggests. If you’re using a liquid fertilizer, mix it half strength (we’ll discuss these two types of fertilizers next). The nutrients feed houseplants at just the right time when they are gearing up for active growth, so they don’t need larger amounts of nutrients yet in order to expand prolifically.
Summer houseplant fertilization schedule
Summer is the ideal time to implement a regular fertilizer program for your houseplants.
Depending on what type of fertilizer you use, determine how often you should apply it in summer.
- The frequency of liquid fertilizer applications can vary from biweekly to monthly, for instance.
- The use of granular products is less frequent, maybe once every two months or so.
- A slow-release fertilizer releases its nutrients gradually, in small amounts, over an extended period of time. For the most part, these products last for three to four months per application.
Two exceptions to these rules:
- Keep your houseplants fertilized all winter long, but do so with half the strength and frequency of your summer applications if you live in a climate that does not receive regular winter frosts. Light levels more than temperatures are responsible for this.
- In tropical climates, where it’s always warm, you can fertilize your houseplants all year round with summer fertilizer.
What’s in houseplant fertilizer?
There is often a combination of macro- and micronutrients in houseplant fertilizers. There is a ratio on the front of a fertilizer bottle or bag listing the three main macronutrients, nitrogen, phosphorous, and potassium. Known as the NPK ratio, these numbers indicate the amount of each of these nutrients in a container. In tomato fertilizers and lawn fertilizers, for example, macronutrient ratios will differ from those in houseplant fertilizers, because each of these groups of plants requires different nutrients. For this reason, a fertilizer designed specifically for houseplants must be used. If you’re buying houseplant fertilizer, that should be your first consideration. There should be a label on the packaging that says “for houseplants.”.
In order for flowers to bloom, phosphorus (the middle number on the container) is necessary. For flowering plants, houseplant fertilizers should contain a higher amount of phosphorus (1-3-1, for example). If you want to use them on green houseplants without flowers, you should use slightly more nitrogen-rich things. In addition, they may contain a balanced ratio of nutrients (5-3-3 or 5-5-5, for example). One houseplant fertilizer is usually sufficient for flowering types of plants, whereas another one should be used for other types. There’s no need to do this unless you’re growing flowering houseplants such as African violets, begonias, and gloxinias.
In addition to primary macronutrients, like calcium and magnesium, fertilizers often contain secondary macronutrients, such as iron, zinc, and boron. Even though these nutrients only contribute a small amount to plant metabolism, they still play a huge role. In addition to these nutrients, you should also look for a small amount of them in your houseplant fertilizer.
Ingredients in houseplant fertilizers
The best houseplant fertilizer will be derived from naturally derived sources of these macro- and micronutrients and not synthetically made. Even though those blue, water-soluble fertilizers are often recommended, they aren’t the most eco-friendly source of nutrition for plants and do not have micronutrients. If you want to feed your houseplant babies, you should use a liquid or granular houseplant fertilizer made from natural ingredients.
Types of houseplant fertilizer
Now that you know when and what nutrients to feed houseplants, let’s take a look at some of the different types of houseplant fertilizers available to decide which one is right for you.
Liquid houseplant fertilizer
Organic liquid houseplant fertilizers require more frequent application than granular fertilizers, but I find them to be the best choice. In addition, liquid fertilizers don’t burn as easily as solid fertilizers. The use of liquid fertilizers made from naturally-occurring ingredients has another advantage because they not only provide your plants with nutrients, but they also encourage them to grow. Several micronutrients, trace elements, vitamins, amino acids, and plant hormones are contained in them, all of which are essential to your houseplant’s growth and health. There are several types of organic liquid houseplant fertilizers. They contain liquid kelp, fish emulsion, compost tea, worm tea, liquid bone meal, rock phosphates, plant extracts, and humic acids, for instance.
Granular houseplant fertilizer
For houseplants, granular fertilizers are available in two forms: loose granulated pellets and compressed fertilizer spikes. Natural ingredients are the most effective in pelletized and compressed granular houseplant fertilizers. The ingredients include dehydrated worm castings, bone meal, blood meal, potash sulfate, limestone, rock phosphate, and other animal-, mineral-, and plant-based substances. For houseplants, you can also get granular fertilizers made of synthetic chemicals. I, however, avoid using them. On the label, you will find a list of the ingredients that are used to make the fertilizer. In the absence of an ingredient list, it’s a synthetic fertilizer.
Slow-release houseplant fertilizers
Slow-release fertilizers are made from synthetic sources of nutrients, and are also referred to as time-released fertilizers. There is a coating around the liquid nutrients. Nutrients are released slowly from the coating over a long time period during the slow breakdown process. By using products like these, you’ll need to fertilize less frequently. The products are very convenient, but be aware that they are not made from eco-friendly ingredients.
Houseplant fertilizer in a nutshell
It is not necessary to fertilize houseplants in an overly complex way. Your houseplant family will experience optimal health and happiness if you use the right products and apply them on a seasonal schedule.