The One Step You Shouldn't Skip When Watering Your Plants

Soil aeration taking place before houseplant watering

The Spruce / Photo Illustration by Amelia Manley / Daryl Cheng

When it comes to caring for your plants, meeting their watering needs is a top priority. There’s one thing that you should be doing when you water your plants, and most plant parents don’t actually know that they should be doing it. If you’re wondering what we’re talking about, it’s soil aeration.

If you’re like us then you must have at least one plant that has super compacted soil. We’re talking soil that seems to be hard as a rock, and when you water it, it doesn’t seem like it’s actually absorbing any of the water. It’s just running out of the drainage holes of the pot. Soil aeration is the solution to this problem. We spoke to an expert to learn more about soil aeration, and the ins and outs of doing it for your houseplants.

Meet the Expert

Darryl Cheng is the author of The New Plant Parent.

Soil aeration is the process of providing an air supply into the soil. Cheng assures us that you don’t need to be aerating the soil each and every time you water your plants. But, there is a reason why you should be doing it every so often.

“In the wild, worms and insects are constantly shifting and breaking up clumps of soil around plants. Indoors, these critters are absent (usually, we hope) so houseplant soil tends to be rather stale except when we water it,” says Cheng. So how do you create pockets of air in the soil to keep it from clumping together? Manual soil aeration. 

How to Manually Aerate the Soil

Take a slim wooden dowel (Cheng uses a chopstick) and gently insert it into the soil. Go about half way down into the pot. Remove the dowel and reinsert it in another spot. Repeat several times or until you have broken up the significant clumps of soil.

Why You Should Aerate Your Plant’s Soil

“By loosening the soil gently with a chopstick [or wooden dowel], you'll break up the dry clumps of soil that naturally develop as the roots repeatedly absorb moisture, which mimics the action of worms and insects burrowing in the soil,” explains Cheng.

You've likely experienced this kind of hardened, dry soil, probably with small plants. As the soil dries out, it hardens into clumps. Sometimes it hardens and shrinks so much that a gap appears along the inner perimeter of the pot.

Clumpy soil might seem like a minor issue, but it really matters. As the roots grow and grow (because you’ve been taking care of your plant and in turn it has developed a healthy root system!), it’s important to make sure the soil is absorbing water so that the roots can too. 

Will This Hurt Your Plant’s Roots?

“The obvious question: Can it hurt the roots? Yes—it's possible to break a few roots here and there, but dry clumps of soil also hurt roots by isolating them from moisture and oxygen, suffocating them until they die off,” says Cheng. Plants are resilient so if some of their roots get a little bit damaged, it’s not the end of the world. However, Cheng reminds us to gently loosen the roots and avoid jabbing at the soil. 

Assessing Soil Dryness

“Probing into the soil also helps you assess soil dryness, although simply lifting a pot will also tell you how much moisture is in the soil,” says Cheng. If the stick you’re using to probe your soil comes out with no soil on it, your plant is definitely thirsty and will need a good drink of water. If it comes out with soil sticking to it, you probably don’t need to water it just yet. Remember that you don’t want to overwater your plants. If you end up doing that, you could cause your plant to develop root rot and that’s really hard to come back from.

Preventing Soil Clumping

There are a ton of different potting mixes and soil mediums out there. From coco coir to pon to perlite to LECA and beyond, the choices are extensive. Using different things like coco coir or perlite to aerate your soil can be really helpful if you have plants that like well-draining soil. However, it’s not great for all plants. Plants that like to stay moist won’t really benefit from adding in a medium that would minimize soil clumping.

“While this can prevent the dry clumps, you may also be watering on an annoyingly frequent basis as your planting medium will not hold as much water,” explains Cheng. So, if you have plants like ferns, peace lilies, or ivy, it’s best to stick to aerating your soil with a stick instead of using other mediums to do it.

How Often to Aerate

“There's no set rule. You will need to learn to assess soil compaction just like how you learned to assess soil dryness,” says Cheng. When it comes to caring for plants, there will always be a learning curve. And just how you took the time to understand the needs of your plants such as how much humidity or sunlight they may need, or how often you need to water them based on the conditions of your home, you’ll have to learn when to aerate the soil.

Each plant’s soil will compact differently depending on a number of factors. Look at the soil and if it seems that the water isn’t penetrating the soil, or your plant is drying out really quickly, give it a little poke around with a wooden dowel. Your plants will be happier for it.