Flushing Your Plants - Why Is It Important

Posted by Daniel Taylor on

Welcome to the first of our Native Growers blog from our team here at Native Hydroponics. In this blog series we aim to look at and explain as much as we can about growing either in a Hydroponics System or a Grow Room Setup.

We've all heard about how important flushing your plants is, whether you're an experienced grower or just getting started. But what exactly is flushing, what does it do and why is it important? Let's take a look.

What is Flushing?

Flushing your plants is the process usually done in the last 2 weeks of flowering before harvest where you remove any excess nutrients and mineral build up in your plants. If you don't currently flush your plants before harvesting, you need to start scheduling it into your plant's growing cycle. Flushing can be done with either plain water or with a flushing agent. We'll look at this in more detail in a minute.

Why is Flushing Important? 

Flushing your plants is one of the most important parts of your growing cycle because it gives your crops a natural and uncontaminated taste. By removing any nutrient or mineral build up in your plants before harvesting, you are ensuring the final crop tastes and smells natural without any foreign elements to interfere. When nutrients build up in your plant they can not only affect the end result but also cause your plants to have restricted uptake and use of nutrients and water. The same can be said for mineral or salt build up. 

Salt and mineral build up in soil
When your plants have excess build up they can't process nutrients efficiently as they are blocked, much like us when we have too much food in our systems. 
When to Flush your Plants?
Flushing your plants is normally done in the final 2 weeks of the flowering period before harvesting. If your plant has an 8 week flowering phase you would want to flush your plants from around week 6 to ensure any nutrients and minerals have been fully removed before harvesting in week 8.
Some experts also recommend flushing your plant in the transition period between the vegetative and flowering stage. This removes any nutrients and minerals aimed towards the growth phase so when you implement your flowering phase feeding the plant is clean and ready to absorb and use the new nutrients without hassle. 

How to Flush your plants?

Luckily for growers, flushing is one of the simplest parts of caring for your plants. There are really only two options for flushing your plants; flush with water only or use a flushing agent. 

Flushing with water is inevitably the most simple and cost effective way. All you need to do is fill your reservoir with clean water (don't forget to check the pH) and then simply flood your growing medium with as much water as it can hold to remove excess build up. Water until the medium is drenched and the water runs out of the bottom - it will look stained and dirty as the build up is removed. 

Flushing Agents can also be used during the final flush which are specially designed to help break down and remove any excess nutrients and minerals. Most experienced growers will use a flushing agent although some still prefer to just use water. The choice is completely down to you and your plants. We find that some plants need that little helping hand to ensure everything is removed, particularly if they have been overfed or have had a strong feeding schedule during the flowering phase. 

Here at Native we stock several Flushing Agents;

Advanced Hydroponics of Holland Final Solution - An organic flushing agent suitable for any type of growing medium

Grotek Final Flush - Available in 6 different scents this flushing agent can help remove excess build up as well as enhance flavour and taste.

Fox Farm Bushdoctor Sledge Hammer - An organic flushing agent that encourages water movement and removes build up during flushing

What is your take on flushing plants? Is it something you already do or have you yet to try it? Do you use water or do you use a flushing agent? 


Share this post



Newer Post →


  • Great blog ! I am impressed with suggestions of author. https://www.amazinghydroponic.com/product-category/hps-mh-light-bulbs-ballast/

    Amazing Hydroponic on

Leave a comment

Please note, comments must be approved before they are published.