Watering Guide

How to keep your house plants happy and healthy.

Words Craig Miller-Randle. Photography Mark Roper



Tangible Media



Plants need water the same way that we humans do. Much of their structure contains water and they use it along with minerals and sunlight to produce energy to grow. Plants have evolved in their natural environments to utilise water both in its liquid form, as rain, and as a gas in the form of vapour or humidity in the air, so where a plant comes from dictates what kind of moisture levels it needs. In the home environment, plants are completely dependent on you to give them the precious H2O that they require to flourish. More than any other area of plant care, watering causes the most grief for people, and it’s easy to understand why. Water too much and your plants will quickly weaken and die; water too little and the same thing will happen. When the soil becomes waterlogged, water fills the spaces where air would usually be, encouraging bacteria that rot the roots and essentially su ocating the plant. If a plant doesn’t receive enough water it simply dehydrates, stops growing in an e ort to conserve moisture and eventually keels over in protest. But the good news is that it’s actually not that hard to get it right. Surprisingly, it’s one of the easiest areas to master, especially if you don’t mind getting your hands dirty – well, your fingertip to be exact. The key to watering any plant properly is learning to monitor the moisture in the soil by the way the potting mix looks and feels: moist to wet soil appears darker and feels cooler, while dry soil looks lighter and greyer in tone and feels warmer. The trick is to dip your fingertip into the top layer of potting mix to get a clear idea of what it looks and feels like 1-3 cm down. Using this method is fast, e icient and accurate. You can wear gloves if you prefer – you’ll still be able to feel the moisture in the soil wearing the thinner latex type, though gardening gloves will only allow you to see the colour of the soil – but for me nothing beats touching the soil directly (then again, I’ve had my hands in the dirt since I was a four-yearold). It’s important to dip into the potting mix because the surface dries quite quickly and relying on sight alone is not enough to accurately judge if a plant needs watering or not. If you want to avoid the fingertip method altogether, you can use a soil moisture meter instead. There are a few di erent types available, including portable ones that you can move from pot to pot and fixed ones that stay with one plant. The downside of these meters is that measuring with the former is slow and investing in the latter is expensive, especially when you have more than a few plants. It’s also di icult to gauge how deep you are inserting the meter into a pot, especially if the pot is large. I have found them inaccurate and gimmicky in the past, although the technology appears to be getting better. Still, for me, the human touch wins hands down, and I encourage you to try it first. Why can’t I just water once a week? Why is monitoring the moisture of the soil in indoor pot plants important? Why can’t we simply water all of them once a week? Well, plants don’t need the same amount of water all year round – in fact, their water needs can vary from week to week and month to month. Factors such as whether the plant is actively growing and the temperature and humidity levels will have a big impact on a plant’s water needs. This is why it’s a big mistake to have a regular watering day when you water every plant regardless of the moisture level of the soil. Many