Usually, the first question we ask ourselves when buying a plant is how often should I water this plant?
The Short Answer: Water Houseplants and Office Plants When They Need It
To keep it simple, the following five suggestions should help you avoid killing your plants.
- The biggest safeguard against problems with watering your plants is going to be drainage. Keep your plants in pots that have holes for the water to drain!
- Check if your plant needs water (by checking the weight or the soil) before simply watering on a set schedule.
- Most plants want to dry out at least a bit between waterings. It doesn't rain every day; so they don't need water every day.
- Ensure soil is fully saturated when watering (drainage is a good indicator). Your plant doesn't want a sip, it wants a full drink.
- Most plants can handle being watered once a week. Use room temperature water. We recommend leaving water out overnight to get rid of any harsh minerals.
The Long Answer: Watering Plants Correctly Depends on Lots of Factors
Most people recommend a set number of days between watering because it's easier to remember and follow. But, the correct answer is more complex - it depends. There are some considerations you have to think about when watering your houseplants.
An equally important question is how do I water houseplants and indoor plants. Many tried and tested ways to ensure that your houseplants or office plants are happy and thriving.
Three import questions to water correctly:
- How often should I water my plants?
- Is Toronto's tap water fine for my plants?
- Is it better to water from the top or let my plants soak up water from the bottom?
To help you become more intuitive with plant care, let's tackle some of the basics of plant care, starting with when and how often you should water your plants.
How often should I water my plants?
The natural habitat of a plant is unpredictable, so an unpredictable watering schedule is okay. The way to water houseplants is to think about their natural habitat.
Most houseplants we grow in our homes come from the tropics. With microclimates that range from deserts to rainforests, plants come from different places with varying conditions.
All we need to do in our homes is give them the amount of water they would have received in their natural environment. If they are potted correctly with sufficient light, most plants can be watered about once a week without causing damage as long as your pot has drainage.
Watering based on the plant's needs is recommended over a set schedule, but a schedule can be a handy guide for when to check on your plants! Since conditions vary from home to home (and season to season) monitoring your plant and checking before watering is the best practice.
Intuitive ways to water your plants:
Lift the pot. Does it feel light or heavy? When a plant is lighter than usual, the water has been used up. This is how most greenhouses water their plants. They lift the trays or hanging baskets and if they feel light, give them a drink.
Touch the soil. Is it dry to the touch? Is it dry a couple of inches deep? Are the drainage holes damp? While different types of plants prefer
different moisture levels, most plants like to maintain a level of wetness to their soil. Although some do prefer to dry out completely. Learn what your plant prefers and the soil will direct you.
Four factors affect how often you should water your plants:
- The type of plant
- The amount of light the plant is receiving
- The season and time of year
- The type of soil and pot you are using
What Type of Plant Do I Have?
Most indoor plants come from tropical regions. In the tropics, it rains hard and then stops. At times there can also be short droughts. Plants can withstand a lot more than we think they can. While some might lose leaves or have issues easily - most will recover when watered correctly.
Think about watering plants in three categories:
1. Plants that want to stay moist
Water when the topsoil is dry to the touch.
These plants are the most demanding; they require more frequent watering approx. every 3-5 days.
Examples: Boston Ferns, Staghorn Ferns, Peace Lilies.
2. Plants that want to dry out partially between watering
Make sure the first few inches of soil are dry before watering or that it is 50-60% lighter than when you last watered it.
These plants fall in the middle of the spectrum - not too demanding, but do not tolerate neglect. They like to be watered when soil is dry about 2 or so inches (aka when 25-50% of the soil has dried up).
Plants that need this watering schedule include: Fiddle Leaf Figs, Monsteras, Peperomias, Money Trees, and Begonias.
3. Plants that want to dry out entirely between watering
Wait for them to be completely dry before watering, when you lift them up the pot should feel pretty much empty inside.
These plants are the least demanding. They like the soil to dry out 100% between watering. Cacti, Succulents, Dracaena, Sansevieria, and ZZ plants are prime examples of this type of plant.
Factor # 2: How does lighting affect my watering schedule?
Ask yourself, how much water would you need (and want) to drink after a 30-minute run vs. a 30-minute walk?
The more energy our body uses, the more food and water we need. Similarly, a plant getting 6 hours of direct sun will need more frequent water than the same plant that's tucked away in the shade getting 1 hour a day. This is because sunlight and water have a strong relationship in photosynthesis.
Photosynthesis is vital to the survival of a plant. It transforms light energy into chemical energy. The amount of light the plant receives directly affects how much energy the plant produces. The more energy it produces, the more water it will need.
Factor # 3: How do seasons and time of year affect my watering schedule?
When the seasons change, specifically during the spring and summer, days grow longer, and the sun becomes more intense. This increase in sunlight means your plant will likely need more frequent watering to support growth. You'll begin to notice that the soil dries out faster as plants go through the growing season, which starts in the spring.
The rule of thumb is water more frequently in the spring and summer and less frequently in the fall and winter. Keep in mind the types of plant you have and how much moisture the plant prefers, and you'll do just fine.
Factor # 4: How does the soil type affect my watering schedule?
The type of potting soil affects watering. Plants come in different soil types. Some potting mixes are fast-draining, while others retain moisture. If you have a plant that likes to dry out and is in a growing medium that retains a lot of water, you will need to adjust your watering accordingly.
Larger plants in a smaller pot will need more water than a smaller plant in a larger pot. When your plants grow into the pot, they will often use more water over time.
The potting mix you use can significantly impact how well your plants do, and they also affect how much moisture your soil retains. We typically recommend adding some perlite or other amendments to encourage drainage when possible.
Watering Techniques - Two Ways to Water Plants
Generally, when you water your plants, you want to make sure to saturate the soil thoroughly. Water your plants until you are sure the soil is moist. There are two ways people typically water their plants.
- Top watering - pouring water over the top of the soil until the soil is saturated.
- Bottom Watering - Letting your plant sit in a tray of water until the soil soaks up enough water to be saturated.
How to Top Water Your Plants
Water your plants until water comes out of the drainage holes.
Ensure that the entire container gets saturated with water to help promote plant growth. This is important during the growth period when roots develop and grow. To water deeply, water slowly across the soil's surface.
Once the water has drained through, empty any excess water within 30 minutes to an hour. Do not let your plants sit in a tray of water for multiple days. This leads to root rot, and it can attract fungus, mold, and pests that might kill the plant.
Try to make sure you saturate the soil and not the plant or its leaves. Some plants, including the Pass it On Plant and many Peperomia won't be happy with getting water on their leaves.
What if my pot doesn't have drainage?
Based on our experience, we strongly suggest using a nursery pot along with a non-draining pot. Excess water might pool at the base if you use a non-draining pot and are not careful with watering. This increases the risk for root rot that might kill the plant.
If you insist on potting directly into a pot with no drainage, your watering schedule will be less frequent. We would also recommend using a moisture meter to avoid overwatering your plants.
Generally, we strongly encourage the use of pots with draining holes. Drainage holes reduce the chances of fungus gnats and root rot - one of the most complex plant diseases to take care of.
How to Bottom Water Your Plants
Bottom watering (butt chugging!) is when you put a plant in a container/tray with water so that the water can soak up through the bottom of the pot to saturate the soil.
To do this, you need a container to hold water, and you put your plant in that container. Bottom watering allows the soil to absorb the water from the container through capillary action. When bottom watering, you want to be careful not to leave your plants in for more than a couple hours; otherwise, you could risk the chance of root rot.
While bottom watering takes a bit longer, it offers some advantages over top watering:
- Reduces the chance of fungus gnats (which are attracted to the moist upper layer of soil)
- Increases the soil's moisture retention (especially helpful for plants that are root-bound or hydrophobic, AKA have trouble absorbing moisture)
- You can simultaneously water multiple plants using one big container!
We almost exclusively bottom water our Peace Lilies because we find it's the easiest way to get them to perk up. When multiple plants need watering in the shop, we fill a plastic bin with water and let the plants sit in while we do other things. After an hour, we then take them out when the soil is evenly moist.
Watering Techniques - Tips and Tricks
How to protect your container plants from chemicals in tap water
Tap water is chemically treated, containing traces of chlorine and fluoride. When your plants absorb water, they also absorb these chemicals. Over time, these chemicals will lead to discoloured leaves. It's pretty easy to make sure your tap water doesn't negatively affect your plants' growth.
Don't water directly from the tap. Pour your water into a vessel - ideally, a watering can - and leave it out for 24 hours before using it to water your plants.
Most chemicals in your water will evaporate during that time, and your plants will thank you for it.
Some plants will show signs of this issue almost instantly. Dracaena Marginatas are sensitive to fluoride, and they will produce yellow tips relatively quickly when watered straight from the tap. Other plants that can be sensitive to tap water include Calatheas, Palms, and Spider Plants.
What do you do when you water your plants, and the soil stays dry?
Have you ever poured a bunch of water into a planter only to lift it out of the planter and see that the soil was still dry? Sometimes, the soil can get so dry that it doesn't retain moisture when you water it; the water runs through the pot. This is called hydrophobia and happens to plants that don't require frequent watering.
When the soil dries out, it can also become compacted and hard to absorb water. Often, you need to water the plant multiple times and let it sit in the water that drains through into the tray.
We had an issue with some resilient Corn Plants at the end of 2020 because we forgot to water them, and once we did water them, the soil wouldn't retain much moisture. We bottom watered these and poked holes in the soil to aerate and create some gaps for water to be absorbed.
Should I use a moisture meter to gauge how moist my soil is?
A moisture meter is a tool used to measure the water content in the soil. It's beneficial for plants that require frequent or infrequent watering, as it can help you avoid overwatering them.
Moisture meters are available at most garden stores and typically cost around $20.
When using a moisture meter, insert the prongs into the soil and wait a few seconds for it to give you a reading. Read the scale to see what level of moisture your soil has, and where in the pot the soil is still damp or dry.
If you're not sure if your plant needs watering, stick the prongs of the moisture meter into the soil and give it a reading. If the number is high, then your plant doesn't need water; if the number is low, your plant needs water. A moisture meter can be helpful, but it's not a necessary tool - you can also use your senses to determine if a plant needs water.
What about watering outdoor plants?
This guide primarily focuses on watering indoor plants. Watering your container plants outdoors isn't much different. However, when plants are directly in the ground, they can pull moisture up with their roots.
So when it comes to watering your plants in containers outside, you should take the above advice. Because the light is more intense outdoors, you likely will have to water these plants more often, but you should be just as diligent with making sure your pots drain.
Plants in a garden are a bit different. When it comes to outdoor and landscaping plants, you should look at what they each need. There is a massive difference between watering your tropicals outside and growing fruits and vegetables. Lots of edible plants, herbs and flowering perennials require much more moisture than tropical plants.
Bringing it all together - the final answer on how to water your plants
It still depends on a number of factors, of course. No two homes are the same after all. Hopefully, this guide provides you with the knowledge and skills to make your plants thrive in your home.
Still, have questions about plant care? We're happy to answer them - just fill out this form.