Plant Care Basics: Water
Knowing when and how to water a houseplant is an incredibly important aspect of plant care. This knowledge helps to fight one of the leading causes of death for houseplants--root rot!
There are a few factors that determine the rate at which a plant consumes water:
Most importantly, light drives water consumption. If a plant is not getting adequate light, it will not consume the water at a fast enough rate. This can lead to your plant’s roots sitting in soggy soil for too long!
Houseplants that are in pot sizes that are too big will take longer to dry out which could cause root rot.
Outside weather and the time of year (season) may also determine the frequency of watering. If it’s been a particularly overcast week, your plants may not be getting enough light to drive their usual water consumption. The season may also impact watering schedules as the summer has much longer days (more volume of light) than the winter does.
How to determine it’s time to water:
In general, water a plant when the first two inches of the soil are dry (there are a few exceptions that can be found in individual plant genus care instructions).
Place your finger or hygrometer into the soil about two inches deep. Only water the plant if you can detect no moisture.
Rather than following a schedule, follow this guideline! Plants may not necessarily be dry every 7 days like many care instructions advise. So rather than using time as an indication of when to water, go actively check the moisture in the soil!
How to water your houseplant:
Once you have determined it’s time to water your houseplant, you may do this by either top-watering or bottom-watering. We’ll get into the pros and cons after explaining how to execute each.
How to top-water your plant:
Your plant pot should have a drainage hole.
Bonus step: Gently aerate the soil with a chopstick before watering. This allows the water to be evenly distributed throughout the soil.
Bring your plant over to the sink so that there is a place for water to run off.
Using the sink faucet or watering can start by saturating the top of the soil (this allows the rest of the soil to get ready to receive the water). Wait a minute or so for the water to be absorbed.
Now thoroughly water the plant until water begins to come out the drainage hole. When it rains it pours!
Let your plant completely finish draining before putting it back on its saucer or in its cash pot. **Root rot can occur if this step is skipped since your plant will be sitting in water.
How to bottom-water your plant:
Your plant pot must have a drainage hole.
Bonus step: Gently aerate the soil with a chopstick before watering. This is an especially important step if your plant has tightly compacted soil.
Set your plant into a tray filled with water a few inches high.
Leave your plant in the tray until the soil is moist throughout. The plant will absorb through the drainage holes the exact amount of water it needs. This can take anywhere between 15 minutes to multiple hours depending on the size of the plant. **Note: if bottom watering in a terracotta pot, it may take longer because the porous nature of the terracotta will cause it to also absorb some water.
If you notice that the plant is not absorbing water after some time, the soil may be hydrophobic (repels water). This can often happen to the soil if it has been left to dry out too long. Just add a little water to the top of the soil so that the water below has something to be attracted to (this is called cohesion!)
You can check that the plant has taken up all of the water it needs by placing your finger a few inches into the soil. If the soil is holding moisture, you can take it out of the tray of water.
Let it drain for a few minutes before placing it back on its saucer or cash pot. **Root rot can occur if you do not give it these few minutes to drain.
So should you top-water or bottom-water? There are pros and cons to each, but the answer may be both.
Top-Watering:
When a plant is top-watered excess salt and minerals that build up in the soil are able to be flushed out. This is very important for the plant’s health, so top-watering should be done at least once a month. Another factor is that most plants in nature receive the majority of their water from rainfall. Mimicking the conditions of nature can only be a good thing!
Bottom-Watering:
In a way, bottom watering can be much easier, especially if you fill a bathtub with water and do multiple plants at once. A word of caution in regards to this: if one of your plants is diseased or has a virus and shares the same tub of water as other plants, it could easily infect these other plants.
Bottom-watering is also a great fix for a plant that has severely compacted soil due to infrequent watering. Done correctly, this method fully saturates the soil in a way that top-watering cannot.
Root Rot
How to get root rot:
Overwatering- This means that you are watering too frequently. It’s important to let the top two inches of soil dry out between waterings.
Massively Underwatering- This means you are watering much too infrequently. Underwatering can shrink the roots of the plant so that when you finally do water, the roots are not ready to accept the water and will rot.
Your plant is in too large of a pot. Pockets of soil that do not contain roots will have too much moisture retention and could create an environment of root rot or soil pathogens.
Humidity
Most plants would prefer higher humidity than the average home can provide (since they are tropical plants), but many plants will do just fine with the humidity in your home. Some plants need humidity more than others, so it’s a good idea to look at individual plant care instructions. In our opinion, the best way to increase humidity is by putting plants under glass, using a humidifier, or grouping plants together. Whenever humidity is increased, you should make sure that the plant is receiving proper air circulation in order to ward off viruses and mold. It’s also important to note that increasing humidity may mean that you have to water less often. So be sure to check the soil before watering any plant! Let’s bust a myth: Misting your plants will not increase humidity and can even cause viruses/diseases.