When it comes to watering out houseplants, it’s just not as simple as “you should water your plant every 7 days”. Although it’s not that complicated either, once we understand how to do it.
In my article Plant watering: don’t kill your plants with over watering – here’s how you do it I mentioned that watering frequency is affected by numerous factors. So, to understand the watering frequency it’s important to understand the factors that affect it.
How different factors affect watering frequency?
Type of plant pot
Generally I would classify the type of pots into 2 groups – porous and non porous pots. There are many different materials from which pots are made, but the most common ones are plastic and terracotta.
Terracotta pots represent the porous group. This means that the pot is breathable, enabling better air circulation and water evaporation through pores.
Non porous pots
Plastic pots, also called nursery pots, are non porous and they will retain moisture for a longer period of time and won’t allow good air circulation through the soil.
If you have a plant in a terracotta pot, the soil will dry out more quickly than the soil of your plant that’s in a plastic pot. So if you have plants that are sensitive to dry soil, it’s good to keep them in plastic pots.
By repotting them in a terracotta pot you’ll always need to look out and be careful that the soil does not dry out. It’s easier to keep them in a plastic pot. We have to make our lives easier whenever we can so we can focus on more important things, right?
Beside this type of plants (that like constant moist soil) I generally like to have all my other plants in terracotta pots.
Check out my article – Plastic pot vs. terracotta pot | Which one is better for your houseplant? where I talk more about the pros and cons of each type of pot.
Type of soil
The type of soil will also affect your watering frequency.
In stores you can find general houseplant potting mix, cactus and succulent potting mix, orchid potting mix and others.. all these actually differ due to the drainage amount.
Cactus mix is a potting mix with really good drainage, with a high percentage of perlite or sand, whereas common houseplant potting mix usually retains more moisture and is predominantly made of peat moss.
Size of plant pot
Bigger pots fit more soil, right? So by pure logic, if you have a bigger pot there will be more soil that retains water.
Read about repotting in my article – Repotting for beginners. This one is really important because I explain why is important to go up only 1-2 sizes when repotting, instead of potting in a big pot right away!
Size of plant
You’d think that this is the same as the small pot-big pot situation, but it’s not.
The bigger the plant gets the bigger is its root system.
Roots have to become bigger in order for the plant to grow bigger.
But what does this mean in terms of watering frequency?
The bigger the root system is, the plant will absorb more water. So if you have a large plant that is, almost to completely, root bound – it will absorb water more quickly than a plant that is in the same pot size but not even nearly root bound.
You’ve for sure heard that you need to water your houseplants more often during spring and summer, and reduce the watering during fall and winter.
In the spring and summer the plant goes through the growing season.
This means it pushes out new growth and grows bigger roots, and it does all that pretty fast. On some plants you can see a new leaf popping out every 5 days! Because of that, your plant will inevitably consume more water. Additional to that, summer is a dry season, which will contribute to faster water evaporation.
The opposite of that is winter aka the non growing season for the majority of houseplants.
The plant does not need that much water and because of the increased humidity levels during winter, the water will evaporate more slowly.
But you should be aware that if you live in a drier area and/or your house has low humidity levels because of the heating, you’ll need to water more often than someone who has higher humidity levels in their home.
Plant spot in your home
Additional to the changing seasons, the placement of the plant in your home can cause the water to evaporate more quickly.
Placing a plant on a south facing window that gets many hours of sun will lead to a more frequent watering.
Plants in areas of your house that don’t get that much sun, like a north or east facing window, will need less frequent watering.
Also, if you have plants that like dry areas and high heat placed on a window with a radiator, those plants will need to be watered more often in most cases.
As I mentioned earlier, some of you may have low humidity levels in your homes due to the heating and some of you may have higher humidity levels in spite of that.
In any case, the humidity levels in your home will also affect the watering frequency.