Understanding houseplants and how to care for them

Houseplants are amazing! They make you happy, help you decorative a space and oxygenate your environment. What could be better?
While plants have specific needs, their ongoing care doesn’t need to be so daunting once you’ve understood the following concepts:

Jump to section:

Lighting
Watering
Fertiliser
Potting
Pest control
Humidity

Lighting

We all learnt about photosynthesis in school right? Well, all plants, whether indoor or outdoor, need light to grow and thrive.

Plants have different lighting requirements, which means that they could require:
Low light: positioned in rooms with south-facing or shaded windows.
Indirect light: positioned in rooms with east-facing windows or spaces that receive bright sunlight from a north or west-facing window.
Bright light: positioned in rooms with north or east-facing windows. Or spaces that get a least six hours of sunlight a day.

It’s important to research what each plant needs and position them accordingly.

If your plants aren’t getting enough light, they’ll start to drop their leaves or become ‘leggy’ (growing tall stems in search of light).

If your plants are getting too much light, their leaves will start to crisp up and develop brown patches.

Watering

If it isn’t already a given, plants need water to survive.

Unfortunately a lot of people overwater their plants when the reality is that most houseplants don’t mind being left to dry out a bit between waterings.

It’s important to only water your plant when it needs it. You can figure this out by sticking your finger down into the top of the pot to see if the soil is moist, or by using a moisture meter. Some soil substrates hold water for longer than others, so I prefer to use a moisture meter because it gives a more accurate read.

When its time to water your plants, it’s important to pour water evenly around the pot. You’ll also need to make sure you don’t let your plants sit and soak in water for long periods of time as this encourages root rot. Avoid this by removing any excess water from your drip trays/decorative pots an hour or so after each watering.

Are you an underwaterer or an overwaterer?

If you’re unsure, common signs of overwatering include: browning edges, yellowing leaves and soft and limp leaves. Fungus gnats can also be a sign that your soil is staying too wet. 
Signs of underwatering include: brown/crunchy edges, dropping leaves and an overall droopy sad-looking plant.

With a growing collection, watering many houseplants can become quite overwhelming. To keep this manageable, I break my house up into different zones and water plants (if they need it) on different days of the week.

My advice: invest in a moisture meter and cut back on your watering in Winter and all will be well!

Fertiliser

Light and water are key to healthy plants, but fertilising your houseplants in the growing season is just as important.

Plants extract nutrients from the soil. When we grow plants in pots (away from their natural habitat), we need to supplement their soil with fertiliser to ensure they get what they need.

Generally speaking, you get organic, non-organic, water soluble and slow released fertilisers that are sold and applied to plants in liquid, spray and granular form.

Each type of fertiliser has its pros and cons, but it really comes down to your personal preference of smell, price, and frequency of use. I buy an all-purpose organic liquid fertiliser which I dilute and water my plants with every two weeks.

In South Africa, common brands of fertilisers include Efekto Seagro, Biogrow, Wonderstix and I swear by Nitrosol because it doesn’t smell!

Potting

Houseplants have different soil needs and the potting mix that you use for your plants is REALLY important! Some plants require an aerated potting mix while others thrive in a sandier mix. I won’t go into too much detail about the different mixes here, but you can read about soil substrates and my go-to potting mix here.

Water needs to be able to pass through your potting mix, so it’s important to grow your plants in pots that have drainage holes. No drainage= root rot!
I don’t like the look of black pots and drip trays, so I usually just keep my pots in pretty, decorative pots and then just take it out when it’s time to water the plant.

It’s important to match the size of the plant to the pot you use. If the pot is too small, it will limit its growth, and if it’s too big, it will encourage root rot.

With time, potting mixes can become compacted. You’ll know this has happened when you water the plant and it just runs down the inside of the pot. To prevent this, I use a long toothpick to regularly poke holes into the soil to help ensure water drains through the soil and into the rooting system. 

Plants should also be repotted once a year or so, depending on the growth of the plant. If you see roots sticking out the bottom of the grow pot, it’s definitely time to repot the plant! When repotting, always use a slightly bigger pot to give the plant some room to grow.

Toxicity

Just a quick note that a lot of houseplants are toxic, so it’s to best to keep them away from children and pests. Rather be safe than sorry!

Pest Control

Plants get bugs, and this isn’t something we can avoid. Some plants are also more susceptible than others, but thankfully a wide variety of treatments exist to help keep things under control!

Mealy bugs, spidermites, scale, aphids, thrips and fungus gnats are the most common pests found on houseplants. They’re bad to have because they’re destructive and suck nutrients from plants and leave marks.

Mealy bug: are white, furry, sticky blobs that live in the crevices of leaves and stems.
Spidermites: are tiny red/white/black spiders that live on the underside of plants. They’re the most difficult to deal with and you’ll know you have them you see webbing on your plants.
Scale: look like raised little brown/black bumps that live on the stems and leaves of plants.
Aphids: are whitey/see-through bugs that group together on new plant growth.
Thrips: look like small greeny/black bugs that live on the plant.
Fungus gnats: are little black flies that fly around plants and lay their eggs in the soil. They’re not as harmful as other bugs, just more of an annoyance.

When it comes to pest management in houseplants, it’s best to live preventatively. You can help prevent pests by isolating new plants when you get them, checking under stems and leaves regularly, rinsing plants in the shower and pruning dead leaves. If you do find bugs on any your plants, it’s best to isolate the ones affected and repot them in fresh potting mix.

When treating the plants for pests, pesticides generally work as a systemic (kills pests over a few weeks as the solution is absorbed by the plant) or as a contact solution (kills pests upon direct contact). And again, it all comes down to personal preference as you can go the organic or chemical route. I have lots of plants and usually go the nonorganic route when I treat for pests.

Examples of organic substances include neem oil, hydrogen peroxide, soap or garlic sprays or diatomaceous earth.

Examples of inorganic substances include Rosecare spray, Efekto systemic granules and Makhro plant care.

Humidity

Humidity refers to the relative amount of water vapor contained in the air. A lot of houseplants originate from humid, tropical jungles, and we need to find ways to mimic this environment if we want to grow them in our homes.

Most plants are happy in a home environment of 40–60% humidity. However some plants need 60% or more to stay happy. Signs of low humidity in plants generally include curly, dry leaves and brown leaf tips. If you’ve noticed this on your plants, you probably need to increase the humidity of your space!

Here are some ways you can do that:

• Give your plants a good misting in the mornings. There is a lot of debate around misting plants, but I can confirm that it has definitely helped me in the past! Misting in the morning is key as it gives the plant a chance to absorb the moisture over the course of the day.
• Invest in a humidifier. Humidifiers work wonders and have health benefits for humans too! There are many different brands available in South Africa like as the Elektra Platinum or the Clicks ultrasonic humidifier. I group my fussy plants together near my humidifier and have it on daily.
• Put your plants on a tray of water with pebbles or stones. This method helps increase the humidity of the area around the plant.
• Group plants together! Grouping plants together looks great and increases the humidity of the environment around them too.

While the goal is often to collect as many plants as possible, the reality is that some plants won’t thrive in your care. Some plant relationships just don’t work, and that’s okay! Our propagation club gives you the space to learn, grow your collection and find what plants work for you and which plants don’t.

I’ve recently culled some of my plant collection so that I can focus on the plants that I really enjoy and know I can care for. It’s important to be realistic about your time and space, and find plants that match that!

Got any questions? Feel free to ask below.