Overwatering is the number one cause of houseplant death. Your plants are more likely to die from too much water than too little and can more easily be brought back from underwatering.
Watering your houseplants sounds simple enough, yet it's something many of us struggle with, knowing when to water and how much to give. Often if you buy a plant from a supermarket or garden centre the care instructions are minimal and sometimes just baffling symbols. That's one of the reasons I started Pure Plants and make detailed care labels for all of my plants so that people know how to care for their plants so that they thrive.
In this article I'll help you get a better feel for how to water your plants. Plus, tips on the best kind of water to use for houseplants and how to recognise the dreaded signs of overwatering. Hopefully, if you follow the advice your plants will thrive.
Best Water for Houseplants
Personally I prefer to use rain water as it's what plants would get naturally, so if you are able to collect it all the better. I appreciate this may not be possible and some houseplants can tolerate the chlorine in tap water better than others. Tap water also contains salts which can build up in the soil over time and eventually cause problems. One thing you could do is also allow tap water to sit overnight. This would allow some of the chlorine to evaporate and also the water to reach room temperature as cold water can shock a plants roots.
How much to Water
Not all plants need the same amount of water, so if you're not sure how much yours need, take cues from nature. Many popular houseplants come from tropical regions of the world where it rains regularly. These species usually have big leaves that use up a lot of water to look good. Plants like these will need more regular watering. Try making a habit of checking on your houseplants at least once a week in the growing season to see if they need a drink. The best way to tell if your plants need water is to stick your finger about an inch into the soil mix and if it feels dry, break out the watering can. If you detect dampness, check back again in a couple of days. For smaller houseplants, you can also pick up the whole container. If it feels light for its size, add water. Then lift it up again, and you'll get a sense of how heavy the pot should feel when the soil is saturated.
The time of year can make a difference, too. Many houseplants grow more during the spring and summer, but not as much in the autumn and winter when they go into dormancy. So reduce watering from late autumn when plants stop growing. Check the soil about every two weeks and allow the top 2 inches to dry out, test by pushing your finger into the soil up to the second knuckle.
Leave cactus and succulents dry unless you see succulent leaves starting to shrivel. Then give a little to barely moisten the surface of the soil.
Best ways to Water
You might be tempted to just dribble on a bit, so you don't risk overwatering. Unfortunately, this won't help your plants much at all because most of their roots aren't right up at the soil surface. It's better to pour enough on to fully soak the soil around each plant, continuing until water starts to run out of the container's drainage holes. If you catch the extra water in a saucer, sometimes your plant's soil will absorb a bit more while it sits in it. However, make sure to empty out the saucer after about 10 minutes, or your plant's roots may rot. Watering in the morning is preferable to evening. That way, any splashes on the leaves have a chance to dry and evaporate faster throughout the day when temperatures tend to be warmer.
Another option is to water from below. Fill a container with water and stand your plant in it so the water is absorbed through the drainage holes. Leave it for about 10 minutes initially. Then check the soil. For small plants this may be enough for larger plants you can keep it in for up to another 20 minutes. Keep topping up the container until the water no longer gets absorbed. This is the ideal method for watering certain plants such as cacti, succulents, and African violets that don't like wetness near their stems.
How to tell if you're Overwatering
There's a reason pots have drainage holes: too much water will literally drown your plants. That's because roots do need oxygen, or they will rot and die. Even with good drainage, keeping the soil constantly wet can make it hard for air to reach the roots. There are a few ways to tell if you are
overwatering your plants before it's too late to save them.
No new growth and yellowing leaves that are dropping off can be signs of overwatering. You may also notice wilting, which can be confusing because that is also a sign of too little water. The trick is to check the soil when you notice these problems: If it feels wet, you probably should go easier on the water. If the soil is dry, you may need to give your plant more water. If a drink doesn't improve things, you may need to adjust the temperatures or light levels your plant gets.
You can also use your nose to figure out if you've got an overwatering problem. Lots of moisture encourages fungi and bacteria to grow in the soil, which can cause unpleasant odours, especially when roots are rotting. If you think you've been overwatering, it doesn't necessarily mean your plant is doomed. Just let the soil dry out a bit before watering again. You could also soak up some of the excess by putting paper towels under the pot. Then start following the watering techniques above. If that doesn't help your plant bounce back, you can also try repotting it with fresh soil after cutting away any dead or mushy roots.
As with everything you learn by experience and you'll get to know what each plant needs.
My top tip is always check the soil by pushing your finger into it or using a moisture metre. If in doubt wait a few more days.