The plant kingdom is vast and diverse; from tiny mosses and lichens to giant redwoods and sprawling aspen groves, plants come in all shapes, sizes, and environments. But there are two things that all plants need: light and water. They are the minimum requirements of keeping a plant alive and they can be darn tricky to figure out, especially when keeping them in houses with different exposures, humidity levels, and temperatures.
While each plant type requires it’s own tailored watering schedule, there are a few general guidelines anyone can follow, at least when starting out, to help make sure your plants get all the moisture they need without risking drowning. I’ll go over some basic rules for all plants to help you acclimate any new green friend to your particular home environment.
Basic Plant Watering
Whenever you bring home a new plant, you should consider the first month or two as a trial period to help you establish the best watering schedule for that specific plant. There are a number of factors that can affect how frequently a plant should be watered that have nothing to to with the plant itself: how dry the air is, the light exposure it receives, the temperature, the particular potting mix it is planted in, etc. All these factors will affect the speed at which the water evaporates from the soil regardless of how much of the water is drunk by the plant, so even if you receive plant-specific watering instructions, you should also consider location-specific instructions when figuring out how often and how much to water. It is for these reasons I recommend that for the first little while, regardless of what you’re told in terms of frequency (the number one question we receive for plants is “how many times a week?”) you do your own monitoring of the soil moisture by checking it every two or three days to get familiar with how quickly it dries out in your particular environment.
The next general piece of advice is that depending on the type of potting medium, whatever the volume of soil in the pot, use 1/3 to 1/4 that volume in water. This is generally enough to saturate the soil throughout the pot without causing too much run-off or leaving dry patches. Again, this is only a general rule of thumb and depending on the previously listed causes of evaporation you may need to use more or less. Test out the amounts you use during the first-month-testing period to fine-tune the amounts. Plants that require higher humidity such as ferns are likely potted in highly absorbent, peaty substrate which will take more water to saturate, so aim for closer to 1/3 volume water. Succulents and cacti, however, like to dry out and come from sandy, arid regions where the soil is fast draining. They are typically potted in a less-absorbent medium so closer to the 1/4 volume rule would be more appropriate. If when watering you find that the water never reaches the bottom drainage holes, you may need to use a bit more, alternatively if you find a lot of water runs out the bottom, use a bit less. Ideally you would have a few drops run out the bottom to let you know it reached that far. Most plants prefer a thorough, deep, water that is then allowed to dry out to a certain dryness; ferns should be watered again before the surface soil goes totally dry (the soil should be soft to the touch, but not super moist), whereas cacti prefer to completely dry out and then some.
With all plant types, with very few exceptions (like maybe a papyrus), plants do not like to have wet feet. Let me repeat (this is very important): Don’t let your houseplants sit in runoff water! In many cases, when using enough water to saturate the whole of the pot, some runoff will occur into the decorative pot or saucer. If it is enough to pool around the drainage holes it’s very important to empty this extra water as it can lead to root-rot. Even plants that enjoy being “evenly moist” such as ferns, would much prefer to be watered more frequently to maintain that moisture level, rather than be sitting in a puddle. This is why we generally recommend keeping your plant in the plastic pot that has drainage and sitting that in a decorative pot, rather than potting directly in something without a drainage hole. While you can do this, you need to provide a layer of rocks or broken pot in the bottom to create a drainage “reservoir”, but especially for beginners this can make it much harder to monitor the moisture level throughout the depth of the soil as you don’t really know how much may have collected in the reservoir. It may also be ok to do with succulents and cacti as long as you don’t tend to over-water; because you generally wait a long time between watering those ones, it’s more likely the whole of the pot has a chance to dry out.
I hope you find these tips useful, if you have any plant-specific questions don’t hesitate to call the store at 613-729-6911, all our designers are quite familiar with all types of plant care and would love to help!