When I was a child, my mother had many plants across the house and in the garden. As we lived in the colder climate of Belgium, some of my earliest memories are of her asking me to move her giant beautiful Yucca plants indoors at the end of summer to help them make it through wintertime. At age 27, I moved to the United States, and it didn’t take me very long to realize that I liked having plants around as well, so I went off and bought a few plants from IKEA to decorate my apartment with.
It was a harsh surprise when one after one, I seemed to be able to kill these plants with relative ease. I’d water them, but then forgot, or thought I was watering them just right, but they still didn’t make it. I remember trying two cane plants in a row, without realizing the things I did wrong, and sadly seeing each of them wilter and die.
What I came to realize is that there’s no such thing as an indoor plant. There are only tropical plants that live indoors where we live, but our environment is rarely similar to what they are used to back home. For instance, even with sufficient watering, our living rooms may not have the humid air they’re used to.
In this blog I’ll outline a few of the things I learned going through this growth experience, in the hope of saving you from a similar fate.
Having had many plants over the years, I learned there are four things which each plant cares about, and which all together form an “envelope of life” for the plant. If the plant lives in an area where each of its needs are met, it will thrive. If any of the areas either exceed or do not meet the minimum standards for the plant, it will slowly wither.
The key four characteristics of any space are:
- Humidity: what is the humidity of the air in the room where the plant sits?
- Sunlight: does the plant get direct or indirect sunlight? How many hours of sun does the plant get in a day?
- Draft: Is the plant at any point in time exposed to wind, either from a window or an open door?
- Water: How much do you water the plant and is the soil moist enough for it, but not too moist so its roots will not rot?
For each location in your home, these four characteristics create a different situation. You have the ability to influence each of these, for instance through watering in better ways, opening curtains, adding growth lights, or adding a humidifier. Every plant you buy is going to have some specific requirements.
Choosing the plant
If you’re not good with plants, you want to start off with some plants that are low maintenance. The ones I was most successful with initially were Peace Lily (Spathiphyllum), Dracaena Lisa, Chinese Evergreen (Aglaonema) and Snake plants (Sansevieria trifasciata). Each of these have in common that they thrive in low to medium light conditions, which is the most common situation for apartment living.
A benefit of the plants above is that each of them is recognized for their ability to improve air quality.
- Peace Lily: Appreciates temperatures above 60 F, keep them away from drafts, keep soil moist and don’t let it dry out, keep it closer to a window if you want flowers.
- Dracaena Lisa: Let the soil dry out on the top few inches if you keep it in a lower light area, but it can be exposed to higher light.
- Chinese Evergreen: Allow the soil to dry out on the top 1-2 inches between watering. Greener varieties need little light, red and orange tinted ones require more light.
- Snake plants: Allow soil to dry between watering, indirect light.
Other plants you’ll have an easy time with include Money tree (Pachira aquatica) and Ficus Benjamina. These are great additions near a window.
Measuring the four characteristics
Prior to modifying the characteristics. It’s helpful to take stock of what the situation is. Sunlight, water can all be measured using common tools such as an XLUX Soil Tester.
Draft can’t really be measured, but is easy to observe by checking whether there’s some soft wind activity. Even if it does not seem like much, if the air is of a different temperature than what the plant desires, such as cold air coming through a door or window, it can be quite destructive.
You’ll also need to get a separate device to measure humidity. This you can measure with any indoors weather station, such as a ThermoPro TP50 Digital Thermometer.
Another way to measure humidity is by simply looking at the type of construction you live in. I’ve found that if you live in a concrete building, such as a high rise apartment building, with lots of isolation, indoors will be pretty dry. If you’re in a wooden construction, humidity will be a little bit higher. If the windows routinely are wet in the morning on the inside, you know you’re in a very high humidity place.
When to modify the environment of a plant
An interesting part of growing plants is simply learning to observe them. While reading Peter Wohlleben’s “The Hidden Life of Trees”, I learned that the biggest difference between plants and humans is time. They simply live on a different time scale, and things happen significantly more slowly. As a result, we don’t always perceive small changes in how our plant reacts to its environment, and sometimes only see these changes when it’s too late. Things to look out for include:
- The color of leaves changing. Are they turning more green (which may indicate they’re getting too little light and more chlorophyl has to form), or less? Are they getting brown tips (an often ill of under- and over-watering, depending on the plan)? Are brown spots appearing, which may indicate illness or a fungus?
- Are there small insects slowly moving across the plant? This may indicates aphids or spider mites, or another type of attack on your plant which you may need to help it fend off.
- Leaves drooping; most often a sign that you’re not watering frequently enough.
- In some cases even smell can tell you something. When a dracaena has one of its unusual flowering moments, you may not even see the flower but can smell it all across your apartment – it’s an acquired taste! Though it depends on the plant, flowering can tell you a plant is doing really well.
Modifying the four characteristics
Now that we know what the state of our surface is, let’s dive in to how we can modify them.
Watering is one of the most challenging things to get right. Each plant has its own requirements, but most of the time you’ll want to strike a balance that allows the plant’s soil to dry out for the top inch or so, before watering. This ensures that the roots of the plant do not rot, but it also doesn’t dry out completely.
It’s very important to start off with a pot that has good drainage. If the pot is fully enclosed, you’ll want to be more conservative with watering than when it has a hole at the bottom and is resting in a place where it can allow excess water to escape.
I’ve found Hydrospikes to be the tool I most frequently use for watering. The spike draws water from a nearby reservoir (such as a water bottle) through a little hose, each time the soil is drier than the ceramic. Hence it provides regular watering without ever overwatering the plant. It’s easy to set up in minutes, but they do fail over time (which simply requires you to clean them and refill the reservoir), so it’s good to keep a close eye on the condition of the plant for first signs of underwatering. I often combine a hydrospike with irregular, once-every-two-week watering, just to make sure.
The Claber is my go-to device when I travel for more than two weeks. It’s a system of hoses and a small pump using a 9V battery. You connect the tiny hoses to each other using little “drippers”, which you hang over each plant pot, and configure the device to water on a regular interval with a simple knob. While you’re out, twice a day, the Claber will send a predefined amount of water through the hoses, watering each of the plants. To avoid accidents, I tend to use this system for smaller plants in pots that require regular watering, and I move all of them into the bath tub so they are close together and ready for the Claber treatment.
Another interesting tip for watering is that some plants are quite sensitive to some of the additives one would find in regular US tap water. While these rarely pose an immediate problem for the plants listed above, I like to regularly water my plants with distilled water I get from the grocery store. When I don’t have it available, I fill a jug of water and let it sit for 2-3 days while the container is open. Some of the problematic substances will evaporate and the water will be less harsh on your plants.
Lack of sunlight, outside of irregular watering, is the main reason why plants fail to thrive in an indoor environment. Many apartments simply don’t have sufficient light for plants to be successful. If you can’t put your plants by a sunny window, it’s best to stick with those that have lower light requirements, such as the Peace Lily or Dracaena.
However, there are ways to solve the light challenge. When you have small plants, you may want to consider a growth light. At one point in time, I bought many Fertile Earth Litestik’s (there an LSG for non-blooming, and an LSB for blooming plants), and eight years later I still happily use them. Results have been mixed but they seem to do the job. However, these are no longer for sale.
More recently, I’ve used an EnerEco growth light which has as additional benefit that it has three buttons with which you can choose the frequency of the light you send. This way, you can experiment and see what grows the plant best – typically blue light will assist in vegetative leaf growth, while red light will support a plant that is flowering.
Low vs Bright and Indirect vs direct light. You’ll often read that a plant prefers indirect versus direct light in addition to whether it needs bright or low light conditions. For a typical apartment, any location not located directly near a window will qualify as a low light condition. Indirect light typically means direct light from an Eastern facing window, or a few feet away from a window that is directed to the South or West. The only condition that really qualifies as Bright Light is a window that points to the South or West, and gets a full day of uninterrupted light. I found that most low light plants tend to tolerate higher light conditions relatively well, but in some cases you may start to see brown specks on the leaves, such as with Chinese Evergreen.
You can address humidity in three easy ways:
- You can put the plant pot on top of a tray wider than the pot that is filled with water and stones. As the stones heat up in the sun, they cause the water to evaporate, which then turns into humidity for the plant;
- You can move plants closer together. As they each transpire water from their roots to small pores on the underside of their leaves, they will evaporate the water and increase humidity around them. Groups of plants are typically happier than individual plants for this very reason.
- You can install an actual humidifier. The only place I’ve had to do this was a 26th floor apartment in Seattle, where even when the heater was off, heat would come in through the hallway door. Average humidity was between 35-45%, which isn’t comfortable for plants nor humans. With humidifiers I managed to get it up to 60%, which was no longer ideal for a human, nor my books, but greatly adored by my Dracaena!
Finally, you can also spray your plants with a little water sprayer. However, it’s important to note that this may cause diseases and fungi to form on the leaves, so I’d recommend only doing this with hardy plants such as a Peace Lily, and be careful with Yuccas and Dracaenas.
Draft is probably the least recognized issue with a plant’s location. However, it is crucial. Mike Sullivan, who wrote the fantastic book “The Trees of San Francisco” notes wind as one of the main reasons the London Plane Trees that line Market Street in San Francisco have not done so well. They are usually a lot larger and more beautiful in any other city you see them, such as London or Paris.
The easiest way to address draft is by moving your plant to a location that typically has less of it. However, you can also put a small shield next to the plant, such as a room divider. Another way of dealing with this issue is by putting plants closer together, so larger plants that are more equipped to deal with draft capture most of it and protect any smaller ones that may be more affected.
When you want to have success in growing plants indoors, it’s important to start off in the following way:
- Choose the location where you’d like a plant to sit;
- Choose the right plant for the location;
- Water it and care for it according to the instructions. If you have trouble consistently doing this, use some of the tips and tricks in this blog to reduce the plant relying on you, and make maintaining it more automatic, through automatic watering aids or by increasing environmental humidity;
- Monitor and watch closely to see if the plant reacts in negative ways;
- Take action based on the tools I’ve outlined in this article to make the plant happy again. Experiment with each of the four characteristics of the plant’s home to see how it responds. Most plants are pretty resilient and if you intervene quickly when things go wrong, they’ll happily work with you and grow healthy again.
Once you’ve got these down, it’ll be easy to upgrade to more difficult to manage plants, and you’ll have the tools to identify and address issues as they arise. Good luck!