How To Flush Soil Without Overwatering the Plant

A soil flush is an excellent way to get any toxic or harmful substances out of your soil and give your plants a fresh start. Following a soil flush with composting, mulching, or other beneficial additions will also give your plant a new set of nutrients to begin absorbing. However, to get the results you’re looking for, it’s crucial for you to know how to flush soil without overwatering your plant.

Here is how you flush soil without overwatering the plant using the traditional method:

  1. Consider additive options. 
  2. Observe your pot. 
  3. Find a drainage spot in your home. 
  4. Add a drip tray to your plant pot.
  5. Pour water slowly over the plant.
  6. Let water flush the soil.
  7. Empty the drip tray. 

Each step may seem pretty straightforward, but there’s a delicate balance of what you should and shouldn’t do when flushing a plant to keep it from getting overwatered. At the end of this article, we’ll take a deeper look at what the process actually is and what are some alternatives that could give you the same, plant-thriving results.

1. Consider Additive Options 

First and foremost, you’ll want to consider whether or not you’d like to use an additive agent to flush your soil. This step isn’t as necessary if you want to use the dunking or bottom watering method, but you’ll still want to decide if you’d like to do it first because it becomes a non-option if you’re already in your tub flushing your plant. 

If you’re flushing the soil to remove unwanted minerals or eliminate salt buildup, I recommend using filtered or distilled water. These water sources are void of minerals, making it easier to leach the contaminants or minerals from the soil.

However, if you are flushing to repurpose your soil, you might want to be ready with some nutrient additives. If you’ve found your soil is hydrophobic, a wetting agent may be in order. Or, if you’re flushing due to fungus, you might want to look at a fungicide

If you decide to use this option, you’ll want to add these substances at the end of your plant flushing process, in an effort to add as many nutrients back into the soil as possible. Still, considering it firsthand can save you a trip to the store!

2. Observe Your Pot 

Once you’ve decided whether or not you’re interested in additives for your soil, you’ll want to look at your pot and see where the blockages are happening.

This step assumes that you are having drainage problems with your plant. Often, this could be due to rubble blocking the drain holes or compact soil at the bottom of your plant. Take a quick look at your drainage and ensure that nothing hinders water from getting out.

Compact or hydrophobic soil can make it difficult for water to drain through it, and the water will instead drain down the sides of the pot and out of the holes. Alternatively, it can compact your soil thoroughly.

Even if water is coming out of the pot, there’s still a chance water might be getting blocked. Try to loosen up any dirt at the bottom of your pot to the best of your ability so the flushing can take place. Otherwise, you’ll end up overwatering the top of your plant. 

If you’ve found some significant blockages during your observation, you may feel like the flush won’t be necessary anymore. You know what’s causing the overwatering, compaction, etc., and you might just want to move forward.

It’s still a good idea to flush your soil if this is the case, as your plant has likely not been absorbing nutrients as it should, hindering its growth process.

3. Find a Drainage Spot in Your Home

Flushing your plant will drain loose soil, toxins, salts, minerals, and other debris that have been holding onto your plant roots that you no longer want there. Some people leach or flush their plants as an alternative to repotting. Either can be a messy process, so the third step is to find somewhere you don’t mind getting dirt and residue all over

For leaching, what works best is a bathtub, a sink, or a shower. This way, your plant can drain all of its water without getting anything else soaked. 

In this video, rather than a shower or bathtub, a home gardener used a large plant pot to leach her plants:

This is also a viable option. You just need a place to provide your plant with enough space to drain and do its thing without getting water all over your house. This might be more or less difficult, depending on how big the plant you’re flushing is. 

4. Add a Drip Tray to Your Plant Pot

Adding a drip tray is an optional step, but you might consider it if you are worried or sensitive about your plumbing. You can capture a lot of soil and other minerals and prevent them from going down your drain if this is an issue that worries you. 

Drip trays can be purchased at most gardening stores or big box stores, as well as on Amazon. If you don’t have a plant tray on hand, a plate you don’t care much for, or a paper plate also works well. 

5. Pour Water Slowly Over the Plant

Now, you can begin the flushing process. With a pitcher of water or a detachable hose, you can slowly begin pouring room-temperature water into your plant. You’ll want to fill up your plant to about four times the pot’s volume and go as slowly as your soil needs.

How to Flush Your Plants

For example, you’ll need to use 1 gallon (3.8 L) of water for a 1-quart (0.95 L) plant pot. If your water starts pooling at the top and won’t go through your plant, this is a sign of the process slowing down. 

At the beginning of your water-pouring process, you can hold your plant above the tub, bucket, or sink if possible. Understandably, this might be difficult to do if you’re pouring with your other hand and you’ve got a hefty plant. 

Enlisting the help of a roommate or friend will help you better see how quickly the water is draining out of the bottom of your plant. If you’re pouring tons of water in and nothing is coming out, there might be some blockages or compaction at the bottom of your pot. 

6. Let Water Flush the Soil

This is the easiest step of the process. If you are holding your plant and pouring water in, you can set it down on the drip tray in the sink, shower, or whatever place you decided would be suitable for water run-off. 

Let your plant drain for several hours. Doing this step for less than two hours won’t allow enough water to drain through. Two to three hours is usually a good baseline, but you can let it do so longer if you have a busy day ahead. 

7. Empty the Drip Tray 

Once you’ve let the water flush, you can empty the drip tray and replace it underneath your plant. You’ll want this drip tray to stay underneath your plant for the next 24 hours or more while your plant continues to flush excess salt, minerals, and other substances. 

You can repeat this process every few months or as needed. 

What Is Soil Flushing?

A fellow plant enthusiast or gardener might have advised you to flush your plants. Their instructions might have been simple enough (take a plant to the bathtub, water it, enjoy) and not given you the why. So why does one partake in soil flushing?

Soil flushing is a practice that entails flushing out your soil to get rid of salt build-up or hard water minerals. This is also called “leaching.” Flushing can, therefore, fix overfertilization and soil toxicity.

If you’re using tap water to water your plants, there’s an especially high chance that there’s some excess mineral in your soil that you can get rid of. You’ll know it’s time to leach if you notice salt build-up, a white crust in your pot, or the tips of your leaves browning.

If you typically bottom water your plants, either because of their preference or size, you should periodically flush your soil to ensure all salt and mineral build-up is flushed out. 

Those of you who are more visual learners might benefit from checking out this video explaining the process in-depth:

Other Alternatives to Flushing 

Flushing your plants is a great way to get rid of salt and mineral build-up, and it can also help you solve any issues you’re having with your soil. Fungus, pests, or nutrient-deficient soil will be positively impacted by this practice.

However, if for any reason, you’re unable to carry through the flushing process, don’t worry. It’s not the only way to solve soil problems.

Depending on your soil woes, you could consider:

  • Repotting your plant
  • Adding new soil
  • Adding compost or mulch
  • Checking pH levels
  • Checking moisture, sunlight, and other variables

If you’re doing a flush as your first attempt at solving a problem but aren’t quite sure what’s going on, a thorough investigation might give you some more guidance on what to do next. 

Final Thoughts

Flushing is a great way to recycle soil and rid your plant of salt build-up. The process is relatively straightforward, but you have an opportunity at each step to use the above tips and tricks to make the process even easier. 

If you’re having problems beyond salt and mineral build-up, you might just need to repot your plant altogether or toss the soil and use a new batch. You can also sanitize your soil to get more use out of it.

Alexander Picot

Alexander Picot is the founder of and its lead content writer. He created the website in 2022 as a resource for horticulture lovers and beginners alike, compiling all the gardening tips he discovered over the years. Alex has a passion for caring for plants, turning backyards into feel-good places, and sharing his knowledge with the rest of the world.

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