Not everyone has an innate green thumb. Luckily, you can easily develop a green thumb by understanding what plants need and how to care for them. Knowing what the essential ingredients are for a happy plant life is more than a good start to keep your houseplants thriving.
The primary factors that all plants need to survive and grow are water, light, and air, as well as nutrients from the soil, an adequate temperature, space, and time.
In this post, I will share what functions all of these factors have for plant life, and what happens when they go missing, as well as some helpful tips to get started right away with making your plants happier than ever.
What Plants Need: The 7 Essentials For Happy Plant Life
There are seven essential factors without which almost no plant can live, no matter where and how it lives:
- Light
- Water
- Soil (= nutrients)
- Air
- Space
- Temperature
- Time
It is important though to note that each plant species has developed its own specific needs for growth, health, and reproduction adapted to their natural habitat. Even though almost all plants need these essentials to live, different species, therefore, require different amounts of each of these essentials.
There are plants that are used to very low temperatures and do not need much water to grow, whereas others thrive in tropical, humid climates and require lots of water, nutrients, and light to grow well.
Some plants have also evolved in specific ways that enable them to do without some of these essentials, such as parasitic plants. Parasitic plants grow on a host plant and “steal” nutrients from its host. A common example of a parasitic plant that you will probably know is the mistletoe (Viscum).
Important Note: How much of each of these essentials a plant needs always depends on what plant type it is. Each plant species has developed its own specific needs which you should consider when caring for houseplants.
It is always helpful to have something visualized to understand it better. Here’s a good children’s video I found that explains (simply but very well) how the different factors essential for plant life combine and what the plant needs them for:
1. Light: The Energy Giver
Light is the primary energy source a plant needs to live. Through photosynthesis (which I will explain in the next paragraph on water), a plant is able to convert light energy into an energy source in the form of sugar (glucose).
More specifically, it is the green pigment called chlorophyll that does the trick of converting energy. Chlorophyll is situated in the chloroplasts, a part of the cells of plant leaves, and they are aptly also called the power station of plants. Hence, only the green parts of plants can take in and convert light energy.
Typically, plants use sunlight to do photosynthesis but also artificial lights work if they cover the right wavelengths of the light spectrum.
Want to know more about what artificial lights you can use as grow lights for plants? Here’s the link to a post where I explain what specifications artificial lights, especially LEDs, need to be used as plant lights.
2. Water: The Driving Force of a Plant’s Metabolism
Just like our bodies, most parts of plants’ bodies are made of water. For one, plants produce their own sugars (glucose) through a chemical process where carbon dioxide (CO2) and water (H2O) react through the energy of light. This process unique to plants is called photosynthesis and is billions of years old.
You sure have heard of photosynthesis before but maybe it was years ago in school and you wouldn’t mind a quick update on how it works, check out this Youtube video which explains it decently:
Water also transports nutrients up from the roots to the leaves and glucose down from the leaves to the rest of the plant’s body. It is the driving force in a plant’s metabolism and plants simply can’t do without it.
Good To Know: Water is not just water. What type of water you use for your plants can make a big difference to their well-being. Get to know more about what type of water is best for indoor plants and how to prepare it in my post linked right here.
3. Soil: A Plant’s Diet and Root Support
The soil provides the plant with the majority of nutrients as well as the necessary support for its root system enabling a plant to grow tall. Healthy soil is rather loose and lets water run through seamlessly while keeping in lots of moisture and providing a good amount of oxygen through air pockets.
As for the nutrients, you can think of the soil as the plant’s grocery store where it gets its balanced diet (adding to its own food factory through photosynthesis).
What are the major nutrients a plant takes in from the soil? The main nutrients a plant relies on are:
- Nitrogen (N): Key element in plant growth
- Phosphorus (P): Promotes transfer of energy from sunlight to plants, stimulates early root and plant growth, and speeds up maturation
- Potassium (K): Promotes transport of nutrients in plants, boosts metabolism, and increases vigor and disease resistance
These nutrients are often referred to as NPK which is often labeled on fertilizers and similar plant products.
Other nutrients a plant needs on a less regular basis are calcium (Ca), magnesium (Mg), and sulfur (S) as well as some trace elements such as iron, manganese, zinc, copper, boron, and molybdenum.
Do Plants Need Soil To Grow?
A commonly asked question that I would like to quickly address here is whether plants need soil to grow. You might immediately nod when hearing the question but the answer is not as obvious as it seems!
In their natural habitats, most plants grow in soil. Though when kept as indoor plants, you can substitute the functions the soil has in nature by other means:
- Hydroponics: You can either grow plants in just water which is called hydroponics. As the roots cannot support the plant when in water, you need to give the plant support by some sort of frame that holds it in place such as a growing pole. Furthermore, you have to provide the plant with all nutrients by using appropriate fertilizer.
- Growing substrates: Instead of soil, a substrate such as expanded clay serves as the soil in which the plant grows. With this method, the root support is given by the substrate, though balanced fertilization is necessary here, too.
Good To Know: Not only using adequate soil makes a difference! If excess water can’t properly flow out of the pot, the soil will be overwatered and your plant’s roots cannot do their work at all. Learn more about why plants need drainage and how to create it in my post linked here.
4. Air: Plants Breathe Just Like We Do
Plants need air to filter out carbon dioxide (CO2) which they use for photosynthesis. What is often forgotten is that plants do not only “breathe” in carbon dioxide but the roots of the plants actually breathe in oxygen (O2) to do their work and take in nutrients.
Another important factor that air brings along is its humidity. Most plant species prefer a more humid environment than our indoor spaces can provide, especially in wintertime when the heating is on. Using a humidifier in winter can prove very beneficial to your plants’ well-being.
Some plants also filter out certain toxins from the air such as formaldehyde, benzene, toluene, xylene, and carbon monoxide.
Do Houseplants Purify the Air? They do, though our living circumstances do not make it easy for them. Read more in my post linked right here about what NASA and other more recent studies say about air purification through plants and which plant types are purifying pros!
5. Space: Above And Below The Surface
Plants physically exist and hence need space to grow.
Similar to when we think of an iceberg, we tend to forget that below the surface, the root system of a plant makes up about half of the plant’s biomass. It is not just the stems and foliage but equally the roots that need space to grow.
Let’s think of a tree: Its root system takes up just as much space as its stem and foliage. This enables the tree to take in enough nutrients from the soil and gain access to groundwater but also to give the stem enough support by embedding it firmly into the earth.
Out in nature, plants try to avoid competition from nearby growing plants by leaving enough space between them. For your indoor plants, this mainly means that to grow well, they need a pot that suits their size. Also, indoor plants preferably get a pot each. Otherwise, the plants will compete over the shared pot’s resources very soon.
How Do You Know If Your Houseplant Needs More Space? Check if there is a lot of overgrowth of roots at the bottom of the pot. That’s a clear sign that the plant needs more space. Also, if you take the plant out of the pot and the whole soil seems to be one big lump tightly clogged together by a dense root system, it is time to repot the plant, too.
6. Temperature: Guiding the Life Cycle of Plants
Given their evolution in a certain natural habitat with a distinct climate, each plant species follows a certain life cycle that is related to temperature. It will germinate, grow, bloom, and propagate given a certain temperature (among other factors).
Kept as indoor plants, this cycle is obviously somewhat distorted, though important to consider if you want to keep them healthy.
Most plants have a dormant and a growth phase while the former is activated by fewer daylight hours and colder temperatures and the latter by more daylight hours and warmer temperatures. Your plants grow more in the summertime and go into a dormant phase in winter.
You can help your plants get proper rest by making sure their spot is a little cooler in winter and by not placing them right next to a heater.
7. Time: Plants Don’t Grow Overnight
All good things take time to grow. This applies to plants just as much as it does to most things in life. Even though some plants are champions at growing fast, such as Golden Pothos, it takes time for plants to adjust to changes in the environment.
As a plant owner, this means you need to be patient with your plants and give them the time they need to adapt to changes you might make to their living conditions.
It also means that it is best not to give into hasty decisions about your plants. Did you move your plants and aren’t sure if the new light conditions are better? Did you repot it but it doesn’t seem to grow more than before? Just sit back and give your plants some time to adjust before you make any further changes.
What Are Limiting Factors for Plant Growth?
Now that we have covered what factors enable a healthy plant life, you should also know about what can limit a plant’s growth and be damaging to its health.
Scarcity Of The Essentials: No Plant Life Without Light, Water, Nutrients
In biology, a limiting factor is usually an ingredient that is missing or scarce for the plant in its environment.
This means that if any of the above-mentioned seven factors are scarce where the plant lives, it will be limiting its capacity to grow and thrive. If one of these factors lacks completely, it might cause the plant to die off. It cannot live without them.
But even if those factors aren’t ideal for a specific plant to grow, it can still manage somehow to keep alive. Also, some of the factors are more important than others, such as water and light.
Example: Let’s say one of your houseplants has long outgrown the size of its pot but you are not repotting it. The plant’s growth will decrease but the plant doesn’t necessarily die due to lack of space. Instead, if a plant gets not a lot of light and sits almost in complete darkness, it will die pretty fast as it can no longer feed itself through photosynthesis.
Of course, all plants have a certain limit of tolerance and if conditions get too harsh for them, they won’t be able to survive. Though generally, plants are pretty tough survivalists and can make it even under dire conditions just to thrive again when the good times are back!
Other limiting factors that we have not yet touched upon are:
Competition Among Plants: Survival Of The Fittest
In densely packed spaces where a lot of plants, especially a lot of the same plant types, grow in the same spot, this will increase competition among plants for all of these essentials such as light, water, nutrients, and so on.
If plants of the same type grow next to each other, they are competing for the exact same composition of nutrients and living conditions whereas plants of different types have varying needs and can better get by next to each other.
Plant Fact: To avoid competition among plants of their own species, many plants have evolved with special propagation techniques that will make sure their offspring don’t grow right next to them. For example, plenty of trees distribute their seeds through the air, letting the wind take them further away from where the mother tree grows. In scientific terms, this method is called anemochorous seed distribution.
External Environmental Factors: Soil Conditions And Natural Disasters
Other limiting factors for a plant to live healthy and grow well can be external factors caused by the environment, such as recurring natural disasters like bushfires, volcanic activity, or landslides. Also, poor natural soil conditions such as a poor rooting depth can be problematic for plants.
Obviously, these external factors won’t be playing a big part in your houseplants’ life as they are well-sheltered and cared for in their pots at home.
Short Wrap-Up: Keep Your Plants Healthy By Meeting Their Specific Needs
Now that you know what plants generally need to thrive and stay healthy, it is important that you know what type of plants you have at home and what their specific requirements are considering these essential needs.
Don’t fret if you don’t already know what type of houseplants you actually have. There are plenty of great plant identifier apps as well as plant care apps to help you figure out what each of your plants needs in terms of water, light, soil, temperature, and space requirements.
I have reviewed the best five plant identifier apps in my post linked right here, check it out to find the app that suits you.
If you prefer to have an app that doesn’t only identify plants but also gives you exact care advice as well as the option to set yourself reminders, check out my reviews of the seven best free plant care apps. I am sure you will find just the one for you!
Related Questions
How To Know If My Houseplants Are Healthy?
It is not always easy to define whether your plant is healthy or what issues it might have. Usually, one starts to acknowledge that something is wrong when leaves start yellowing or the plant is wilting altogether.
I recommend doing regular health checks on your plants. Some simple steps can easily be integrated into your watering routine and will help detect any issues such as diseases or pests early on.
Read more about what steps a plant health check should include as well as helpful first aid tips for your plants in my post linked right here.
How To Water Indoor Plants?
We all know that water is essential for happy plant life. However, knowing how to water your houseplants is not as easy as it sounds. Especially overwatering is a common mistake among houseplant owners.
Learn more about how to water your indoor plants appropriately in my complete guide linked here where I explain what to pay attention to when watering your houseplants.
Do Plants Like Music?
What else makes plants happy? Some experts claim that exposing your houseplants to music can promote better growth and health in plants.
Intrigued? Find out what types of music promote growth and what to keep in mind when listening to music with your plants in my post linked right here!