Why Does My Soil Dry Out So Quickly?

This post may contain affiliate links. Read the full disclosure here.

One of the most important things to learn when you’re first starting out with house plant care is figuring out what kind of plant caregiver you are.

Over watering is usually cited as being the most common cause of house plant death, but it’s not an issue for me, because I’m a plant neglecter.

It’s one of the many, many, symptoms of ADHD – I literally forget that my plants exist and need watering, even though it’s literally my job.

Soil drying out too quickly is a death sentence for my plants. It can’t stay too wet, because bacteria will start to flourish and I’ll get root rot, but if it’s drying out more frequently than once a week, I need to do something about it before the roots shrivel up and they die.

There are a few things you can do to stop your plant’s soil from drying out too quickly; just make sure you’re not going too far the other way.

If the soil is staying wet for more than two weeks* then you’ve gone too far in the opposite direction.

*I mean wet wet – as opposed to ‘not dry’. Like an 8 on the moisture metre rather than a 4

Your plant is in too small of a pot

Plants being rootbound isn’t that much of an issue to the plant, as long as you’re taking the time to soak it and feed it. However, if you’re a busy person that has a slapdash ‘pour a jug of water over the soil’ approach, then your plant may end up underwatered.

As plant roots grow, they’ll gradually displace the soil in the pot. Less soil means that when you do water, most of the water will just drain away, and the roots won’t have a chance to actually absorb the water.

The soil that does remain will dry out quickly because the roots will absorb any water quickly.

How to fix it

There are two approaches:

1 – You could trim the roots

I have an article on this here.

Root trimming gets a lot of hate in the house plant community, and I kind of get it. It’s largely unnecessary and can potentially lead to problems down the line unless you’re diligent about your plant care.

A certain-sized root ball can only support so many leaves, although that can be a surprisingly large amount if they’re cared for properly.

I don’t really advocate root trimming unless you don’t, for whatever reason, want to increase the size of the pot. I only put it first because I have more to say about repotting.

Root trimming is fine, but you can only get away with it for so long – eventually, the lower leaves will die of old age and you’ll either have a weird-shaped plant, or you’ll have to cut it right back.

2 – You can re-pot the plant

This is the approach I’d suggest you take because there’s only so long you can keep trimming the roots before you compromise your plant’s growth (unless you want to keep it at its current size and keep propagating it).

I have a whole article on repotting here, but it’s basically a case of moving your plant to a bigger pot and adding more soil.

Your goal may be to stop the soil from drying out too quickly, and up-potting the plant will definitely help with that BUT it’s important not to think ‘hmm how can I avoid EVER having to do this again?’ and buying the biggest pot you can find.

Putting your plant in too big of a pot will result in the soil staying too wet for too long and you risk root rot. It’s over-watering by proxy.

I can’t really say ‘increase the pot size by x-amount’ because it depends on how big the plant is – a large, established plant could handle a bigger jump in size than a baby one. So I’ll just say use your judgement.

If the plant is small, I generally go up one pot size (pot sizes are usually measured by the diameter of the pot across the top and go up in increments of a centimetre). Larger plants can go up a size or three.

Your potting mix doesn’t retain water

When I first got into house plants, I got a bit obsessed with finding the ‘best’ potting mix for my plants.

However, due to the way my brain works, I could only have one potting mix that worked for all my plants. Which automatically means that it was only ever gonna be the best potting mix for some of my plants.

A cactus and a fern could definitely thrive in the same soil but only if their caregiver was going to take that into account with her care schedule (rather than every month going ‘shit! The plants! And throwing a tonne of water at them).

How to fix it

Well-draining soil mixes are a hit with plants IF you keep up with watering them. Rather than figuring out the best soil mix for your plants, you need to figure out the best soil mix for YOU.

You can’t go super dense without risking damaging your plants, but there’s nothing wrong with regular, store-bought house plant potting mix. It’s a bit denser than homemade aroid mixes, but if you struggle to remember to water, it might be a good idea.

You have the soil in bright sunshine

Sunshine = hot. Hot = dry.

You could move the plant, but a lot of plants like to be in bright light (as long as they’re properly acclimated).

How to fix it

Rather than resorting to moving the plant, try covering the soil. Large pebbles or gravel work well, or even tinfoil.

For those of you with cats, there’s now the bonus that your little furry friend *might** struggle to dig in your plants.

*No promises here.

The soil has become hydrophobic

Hydrophobic soil is soil that doesn’t absorb water anymore.

It’s not always easy to tell if the soil has stopped absorbing water, because water can make its way into the tiniest crevices, making it appear that it’s being absorbed when in fact it’s just following the crevices through the soil and out of the drainage holes at the bottom.

Sure, you’ve added water to your plant, but the roots haven’t seen a drop of it.

How to fix it

A couple of options:

1 – repot completely

If you think that the soil is of poor quality, or that the plant is due for a repot, go ahead and change the soil.

Take care to remove as much soil as possible from the roots so that when they’re in the new pot they can get to work absorbing water without a layer of dry soil on them.

2 – soak the soil

One of the benefits of bottom watering is that the water is wicked up from below, reducing the chances of the soil getting compacted.

Even hydrophobic soil will wick water up over time, and as the water permeates, the soil will loosen up.

It may take a little while (even a couple of days) to thoroughly soak the rootball, but you can speed this up by putting the pot in a deep dish and having the water level nearly as high as the soil, so that the pressure of the water will naturally help it wick up faster.

You’re watering your plant too quickly

This is similar to hydrophobic soil but can happen to uncompacted soil.

Water always follows the path of least resistance, and if you water the plant too quickly, the water will just run through one crevice without touching the roots.

This often happens when we’re in a rush OR when we use something like a glass or mug to water.

How to fix it

  • Make sure you either use something with a long spout to water so that you don’t go too fast OR you’re especially mindful of going slow if you’re using a jug
  • Bottom water your plant every now and again
  • Use a chopstick to stir up the soil to reduce compaction

Your humidity is too low

Dry air will dry out your soil quicker. Er, that’s about it really.

How to fix it

Add a humidifier, try one of these non-humidifier tricks, or stick to plants that like to dry out and be in a dry atmosphere.

The soil has become compacted

If you exclusively top water, the soil can get compacted over time. As I’ve already mentioned, compacted soil doesn’t absorb water properly, and the water finds the path of least resistance, and the majority goes out of the drainage holes.

How to fix it

  • top water every now and again
  • reduce compaction by using a chopstick to break up the soil
  • repot – soil that’s very compacted is often older and less nutrient rich
  • Add soil amendments like perlite and orchid bark to reduce compaction

Conclusion

If you’re into a bit of casual overwatering, you might be happy that your soil is drying out quickly BUT it’s worth remembering that if the soil is too dry and compacted, the water may not be reaching the roots, however often you’re watering.

Leave a comment