Like all living things, plants need energy and nutrients to carry out their bodily functions. Since plants don’t actually eat as we do, or like our pets do, it’s easy to forget that vitamins and minerals for plants are essential for health and growth!
Plants require minerals to grow leaves, stems, and roots. Proper nutrition is essential for seed, flower, and fruit production. Plants also need minerals to produce chlorophyll and carry out photosynthesis, the process by which they convert sunlight into usable energy. Vitamins and minerals are absolutely necessary for water absorption and circulation. Plants even need these nutrients to facilitate nutrient uptake. (Yes, plants need nutrients to get nutrients!)
The proper balance of vitamins and minerals for plants is essential for growth, reproduction, and general survival, so this is something you’ll need to pay attention to as a houseplant owner. In this article, we’ll review the reasons why vitamins and minerals are so crucial, which vitamins and minerals your plants will need, and how you can supplement these vitamins and minerals to keep your plants as healthy as possible.
Let’s get to it!
Table of Contents
Why Do Plants Need Minerals and Vitamins?
Plants require vitamins and minerals—as well as energy they produce from sunlight—to carry out every bodily function. This includes respiration, photosynthesis, cell formation, enzyme and hormone production, water and nutrient uptake and transportation, etc. Even with energy from the sun, plants cannot function properly without vitamins and minerals. All living things, both plants and animals, require vitamins and minerals for optimal health and growth.
If your plant is suffering from nutrient deficiencies, you might notice yellowing leaves, slow growth, smaller and/or fewer leaves, and thin, flimsy stems. These issues can have other causes, of course, such as improper watering, insufficient light, insect infestations, or disease, but if you don’t notice other signs of these problems and you haven’t fertilized or repotted in a while, your plant might need a nutritional boost!
Vitamins and Minerals in Potting Soil
In nature, organic plant and animal material break down into the soil, which makes it rich in nutrients and provides a steady supply of vitamins and minerals that plants can absorb as they grow.
Potted plants rely on the nutrients present in their potting soil. This isn’t a lot of soil to draw from, and a plant can easily use up the nutrients in its pot within a few months. Since organic material isn’t constantly breaking down, it’s important to add nutrients to potting soil.
In potting mix, nutrients can come from materials like worm castings, compost, guano, fish meal, manure, etc. Pellet or liquid fertilizers are also important for keeping nutrient content high and providing plants with a steady supply of vitamins and minerals.
It’s also a good idea to repot your plants every once in a while so your plant has access to fresh, nutrient-rich soil every year or so. This also prevents soil from becoming old and compacted (hardened), which can restrict root growth as well as water and nutrient absorption. Going up a pot size also gives your plant’s roots more room to grow!
Which Vitamins Do Plants Need to Grow?
Like humans and animals, plants need a variety of vitamins and minerals for optimal health and growth. Here are a few key nutrients that support different areas of the plant, and that every gardener should know about!
Plants typically need larger amounts of some nutrients and smaller amounts of others.
Vitamin C has been shown to aid in plant growth. Vitamins A, E, and a range of B vitamins can help protect plants against disease and even some household pests.
Most fertilizers will contain various vitamins appropriate for plants, and repotting your plant every year into a nutrient-rich soil should also provide a steady supply of these vitamins to your plant’s root system.
Best Vitamins for Plant Foliage
Nitrogen is the most crucial mineral to support plant growth, leaf formation, and chlorophyll production. Most fertilizers will contain plenty of nitrogen, so you won’t have to specifically check for it on the label. Magnesium also encourages plants to produce chlorophyll, which creates their green coloring, but most fertilizers usually contain that as well.
Since leaves are crucial for plant health and growth (they are primarily responsible for photosynthesis, after all), most fertilizers are geared toward encouraging foliage growth and increasing chlorophyll.
Best Vitamins for Flowers
Not all plants produce flowers, and not all flowering plants will flower indoors due to factors like decreased light. But if you do want your plant to flower (or if you have something like an African violet that is meant to bloom frequently), your fertilizer choice can encourage or discourage blooming.
Phosphorus in particular is responsible for supporting flower growth, so flowering plants may do best with a fertilizer that has a higher phosphorus content. (Again, do your research before you buy!)
Can You Give Human Vitamins to Plants?
Humans require some of the same vitamins and nutrients that plants do in order to be healthy. You might see a lot of recommendations online to crush human multivitamins and add them to plant water or to throw expired vitamins into your garden, and we’re not saying that’s bad advice. However, not all vitamins are created equal, and there’s no way to tell how a particular human vitamin supplement will affect your plant.
We believe you’ll get better results from using fertilizers and supplements made specifically for plants. You’re less likely to over- or under-fertilize when using a fertilizer as directed than when you’re adding a bunch of random, manufactured stuff to the soil!
Minerals for Plants
Minerals are naturally occurring substances that are made of one or more elements. Unlike vitamins, they’re inorganic substances, even though they’re found in organic as well as inorganic material. These are found pretty much everywhere in nature—in plants, animals, soil, rocks, etc.—and are essential for carrying out bodily processes in plants and animals.
What Minerals Do Plants Need?
The most important minerals that plants need in the largest quantities are nitrogen, phosphorus, and potassium. Nearly all fertilizers will contain plenty of these (aside from possibly some specialty fertilizers). The ratio of these nutrients is represented on the label by a three-digit code called the N-P-K ratio, which indicates each mineral’s percentage by weight. For example, a fertilizer with an N-P-K ratio of 20-20-20 means that fertilizer contains 20% nitrogen, 20% phosphorus, and 20% nitrogen.
Sulfur, magnesium, and calcium are also crucial in smaller amounts, along with trace amounts of zinc, copper, and manganese.
Different plants require different balances of these nutrients, so it’s worth it to do a little research before choosing a fertilizer for your houseplants. Overall, a fairly balanced fertilizer should work for most of your plants, but it never hurts to Google it and have a few options on hand to keep some of your fussier plants happy.
When your plants get all the nutrients they need in the right amounts, you’ll notice much more vibrant colors, stronger stems, thicker and healthier foliage, more flowers (for flowering plants, obviously), more fruit (for fruiting plants), and faster growth overall.
Nitrogen
Nitrogen is necessary for chlorophyll production and for growth in the early life stages. Without nitrogen, plants will appear yellow and sickly.
Phosphorus
Phosphorus is primarily responsible for the growth of stems, flowers, leaves, and roots, as well as transferring energy through the plant. It also plays a role in metabolism and nutrient uptake.
Potassium
Potassium plays a critical role in plant respiration, water retention, and flower formation. This nutrient is important when your plants are about to bloom!
Calcium
Calcium plays a role in cell wall formation and overall plant structure, much like how it helps us build strong bones.
Magnesium
Magnesium plays a key role in the production of growth enzymes and in photosynthesis. Plants only need this in small amounts, but it’s a nonnegotiable nutrient!
Sulfur
Sulfur is important for allowing a plant to use nitrogen to produce chlorophyll, and also for supporting growth.
Manganese
Manganese assists with the production of growth enzymes and in metabolism. It’s only required in tiny amounts, but a little goes a long way!
Zinc
Zinc is responsible for metabolism and hormone production that prompt a plant to grow.
Copper
Copper is key in the production of fruit, flowers, and seeds because it assists in cell growth.
Iron
Iron is crucial for the production of chlorophyll and in moving oxygen around the plant, but plants don’t need a lot of it. The trace amounts in most fertilizers will do the trick!
Boron
Boron is important in small amounts because it aids in seed production, cellular health and development, and the transport of sugars (energy) throughout the plant.
How Does a Plant Get Minerals?
Minerals are present in both organic material from plants and animals and in inorganic material that breaks down into the soil and is later absorbed by a plant’s roots. This is why it’s so important to add minerals to your houseplant’s soil and keep the pH balanced to aid—or at least not inhibit—the uptake of these materials. You can add minerals with actual fertilizer or by adding mineral-rich natural substances to the soil.
Supplementary Vitamins and Minerals for Plants
Fertilizer is often mistakenly referred to as plant “food” (we’re guilty of this too, but “plant food” just sounds better than “fertilizer”!), but plants actually get all the food, or energy, they need from sunlight. Vitamins and minerals, however, are completely different requirements that come from the soil.
Think of it this way: you can eat empty calories from foods like donuts and soda and get lots of energy, but you still need vitamins and minerals from more nutrient-dense foods like vegetables, or from supplements.
Fertilizer is basically a multivitamin for your plants, much like the vitamin pill you might take every morning or the gummy you give your kids with their breakfast!
How to Use
Plant fertilizers typically come in two different forms: solid (pellets, sticks, etc.) and liquid that you can dilute in your plant’s water.
Different gardeners have different preferences, and both forms come with advantages and disadvantages.
Solid fertilizers last longer and have to be used less often, but it’s also difficult to control how many vitamins and minerals your plant is getting, which can lead to over- or under-fertilization.
Liquid fertilizer is easy to use and allows you to have greater control over how much nutrition your plant gets, but it must be used more often. Remembering a fertilization schedule can be tricky, so sometimes this can lead to under-fertilization if you forget to fertilize your plants like I used to!
Each fertilizer will be a little different, so it’s critical to read the instructions and follow them exactly. If you’re using a solid or pellet fertilizer, be sure to follow the recommended measurements and schedule. If you’re using a liquid, make sure to dilute properly, or you risk chemically burning your plant’s roots!
How Often to Apply
This will also depend on the specific fertilizer you use. Solid fertilizers will need to be applied less often, sometimes as little as every six months, while liquid fertilizers will need to be used as often as weekly, or with each watering. Again, read the label.
In general, you’ll need to fertilize more often in the spring and summer when most houseplants are actively growing and less often in the fall and winter when some plants may become dormant.
This isn’t a hard-and-fast rule, however. Since the climate in our homes stays relatively steady throughout the year, your plants might grow in spurts year-round instead of having long periods of growth and dormancy.
The Perfect Vitamin and Mineral Supplements for Plants
We know that vitamin and mineral supplementation is crucial for growing healthy houseplants. After all, there’s only so much nutrition available in a pot of potting mix.
But getting the right balance and remembering when and how to apply fertilizer can be a pain. And we know you have enough on your plate as it is!
I kept forgetting to fertilize my plants, and as a result, some of my poor houseplants developed nutrient deficiencies, which showed up as browning and yellowing on the leaves as well as slower growth than what I wanted. As a busy mom juggling childcare and a business, I just didn’t have the brain space to remember a fussy fertilization schedule. And I knew I wasn’t alone!
That’s why we developed Indoor Plant Food: to take the guesswork out of fertilization so you can grow the healthiest, more beautiful houseplants with the least amount of effort. After all, the best fertilizer is one you’ll use!
We formulated Indoor Plant Food to be well-balanced and suited to just about any type of plant you’d keep indoors. The N-P-K ratio of 3-1-2 ensures a good balance of the major necessary nutrients, and this formula also contains small amounts of the micronutrients plants need for strong structure and steady growth.
It’s not absolutely perfect for every plant (we have some specific articles and sites to help you care for some of the fussier varieties that might have additional vitamin or mineral requirements), but nearly all houseplants will do very well with this fertilizer. That way, you only have to use one fertilizer for everything instead of mixing a different solution for each plant! (We don’t recommend using this for succulents, but they don’t need much fertilizer anyway.)
Indoor Plant Food is also gentle enough to use with each watering without risking chemical burns on your plant’s roots. We wanted you to be able to just work this into your regular watering routine instead of adding an extra, irregular step that’s easy to forget.
If you’re new to fertilizing your plants or if you just want an easy solution that will nourish your plants without a lot of guesswork, Indoor Plant Food is perfect for you! Get it on Amazon here.
It’s also common for commercial fertilizers to be low or completely devoid of some essential trace nutrients like boron and zinc, and contain no vitamins whatsoever. Fertilizer helps, but sometimes you need just a little something more.
Houseplant Multivitamin was created to fill in the gaps left by most fertilizers. If you really want to make sure you have your plant’s nutritional bases covered, give it a try! It is completely organic and contains no urea or other harmful ingredients that may cause chemical burns to your plants. Get it on Amazon here!
Supplying your plant with enough vitamins and minerals, in the right amounts, is a crucial part of houseplant care, just like watering, pruning, and making sure your lighting conditions are ideal. Luckily, it doesn’t have to be hard or complicated! You have plenty of options for fertilizer, ranging from precise and dialed-in to quick and easy. Pick the solution that works best for you and your plants.
