I remember the day when I bought my first houseplant for my own apartment. It was back in 2014. I chose a Dracena Marginata and I named it Frank. I didn’t know anything about it, literally anything. So I asked the saleswoman how often should I water it and she gave me a straight answer: “Water it every 20 days with 750ml of water”.
Back then I liked plants, but I never had the need to buy any. I knew I wanted just one bigger plant to give more life to my apartment. Back then I also thought that there’s an exact amount of days for each plant after which I have to water it.
So at that point I had one Orchid and Frank. I was told that I need to water the Orchid every 7 days and now I had Frank that needed watering every 20 days, so without questioning I followed that “rule”.
Let me get to the point of this little background story… 99% of the time people will tell you “you should water your plant once a week” or “every 15 days” and other similar advice. Long story short, these kind of advice can kill your plant! – as I did with one of Frank’s stems (I got it with 3 stems like they are usually sold, and the smallest one rotted).
Over watering can lead to root rot and that can be deadly for your plant.
But why this advice doesn’t make sense? Because there are numerous factors that affect the watering frequency – drying of the soil.
- Type of plant pot
- Type of soil
- Size of plant pot
- Size of plant
- Placement of plant
- Home conditions
Let’s take Frank for example..
He’s in a 20cm plastic pot. I have another Dracena (Frank Jr.), a smaller one that I bought in Ikea in 2017. Frank Jr. has less soil than Frank because the pot is much smaller (10cm pot).
Because Frank has more soil, Frank will retain more water and it will take longer for that soil to, at least partially, dry out. Keep in mind that Frank and Frank Jr. are the same exact type of plant.
So maybe it’s true that Frank will need water every 20 days but what about Frank Jr.? He’ll definitely need water sooner than Frank.
There’s also the difference between plastic pots and terracotta pots, for example.
If you’re interested to read more about how all these factors affect your plant check out my article – 7 factors that affect your houseplant watering frequency. In this article I go more into detail about how each factor affects watering frequency.
You can see how many different factors can affect how much time will pass between watering.
Fortunately – there is a general rule that is OK to follow for 95% of houseplants, and that’s “the finger rule”.
GENERAL RULE – “THE check the soil with your finger RULE”
Generally, if you are not sure when you should water your plant or maybe you don’t remember when’s the last time you watered it, go with the simple “finger rule”.
Stick your finger into the soil as deep as you can and try to feel if the soil is dry or moist.
If the first few cm (couple of inches) are dry, it’s time to water your plant. If you can feel that the soil is moist, wait for a couple more days and then go back and check.
Depending on all the factors mentioned above, some plants will need watering as often as every other day, and some only maybe every 6-8 weeks!
But, there’s always an exception to the rule, right?
Some plants like to dry out between watering, and on the other hand some plants will never forgive you if you let the soil to (even partially) dry out.
In my experience, here’s a couple plants of both extremes:
Likes to dry out between watering: Pothos, ZZ plant, Monstera Deliciosa, Sanseveria, Dracena Marginata, Dracena Janet Craig, Kalanchoe (like succulents and cactus in general)
Keep in mind that I’m talking about watering and not the humidity conditions because some of these plants, although they like that the soil dries out between watering, also like humidity. These kind of plants I mist every couple of days!
Letting the soil dry out doesn’t mean that you should keep the soil dry for a long period of time!!
Likes moist soil: Maranta, Calathea, Stromanthe, Mainden Hair Fern (usually most types of Fern also), Fittonia