How to Flush Marijuana Plants Before Harvesting

how to flush marijuana

“Flushing” is a word you may not be comfortable with when you start out as a weed grower. While frenzied thoughts of trying to push a cannabis plant down a toilet growing come to mind, flushing is when you avoid feeding nutrients to the plants and instead of giving them water. In fact, the procedure sounds as simple as that; however, learning exactly when and how to flush marijuana plants is always a more sophisticated ability. Once it comes to harvesting the pot crop, many people believe everything matters is the time and the actual processing process. Furthermore, several other things do come into play, to tell the truth. One such thing is pre-harvest flushing.

The Purpose of Flushing Before Harvest?

Flushing is a free and simple technique that will enhance your cannabis buds’ consistency and smoothness before harvest. Sounds sweet, doesn’t it? Naturally, it is! Yet farmers do need to be vigilant about pre-harvest flushing because if you do it too early, you might potentially damage your output (and your yield as well)!

The flushing process means only giving the plants pure water and no nutrients for a while before harvesting. For growers who usually give their plants water with nutrients in it, using the same sort of water that you currently use, you can water your plants as usual, except you don’t add any nutrients. The method changes depending on the setup of the plant, but growers most commonly flush their cannabis play this way, ranging for a few days up to 2 weeks. Flushing may be vital and is not too hard to do. That being said, pacing can be tricky because it can turn the end product into something awful or amazing.

How to Flush Marijuana Plants

Flushing is more than simply splashing water on the pot plants. In fact, there should be almost no water blasting. Flushing weed, once again, literally means pumping liquid water through the soil or the medium you use. By excessively watering the plants with water that has a pH range between 5.5-6.5 (hydroponics setup) or 6.0-6.8 (natural soil), perform a flush when attempting to avoid a nutrient lockout or when swapping nutrients Saturate the pots full, and repeat for 15 minutes. The flush will remove any impediments and unnecessary elements. It will break any stalemate growth and make way for your new feeding cycle.

Instead, just spray the pot plants with pH-neutral water at the moment you would usually feed them. This might just be water from the tap that hasn’t been processed at all, so you certainly should test the pH level of this water to make sure it’s safe to feed your plants. The good news is that most water from the tap applies in the United States, but it’s still worth testing again because using the wrong pH and feeding it to the plants could have any significant harmful effects.

You should also buy a TDS meter to calculate the total dissolved solids, especially when it appears dusty or discolored. The average TDS of normal drained water (the “absolute dissolved solids”) is 1300ppm. You will use this meter to keep flushing the pot plants until down to 50 ppm is the water flowing out.

You may use a TDS reader to assess how clean the water runoff is, to make sure a flush was successful. You want the TDS reading of the water that flows out of the pot to be similar to the TDS reading of the pure water from which you wash. This test would mean the nutrients were washed away from the soil.

How Long To Flush?

Flushing plants are usually recommended for a few days to 2 weeks. This is a pretty decent norm, I guess, to go into. When you grow in modified super soil, flushing without nutrients for more than two weeks is likely to stall the buds’ growth, which we don’t want at the flowering stage!

  1. Flush duration for Soil Growers: one to two (or more) weeks
    Growers of soil will have the longest wash, from 1-2 weeks. That is because a certain number of nutrients are already left in the soil. You don’t have to think about flushing for super soil farmers who haven’t used any nutrients from seed to harvest since you’ve been giving clear water from the beginning. Your soil microorganisms have, as needed, fed nutrients directly to your plants, and it is very unlikely that you will have some form of nutrient build-up.
  2. Flush duration for Coco Growers: a few days to a week (or less)
    Coco coir doesn’t hold a lot of extra nutrients, and only one or two waterings of normal water will flush out most nutrients. Hence growers use coconut coir can only flush their plants from a couple of days to around a week, depending on how quickly the plant turns yellow.
  3. Flush duration for DWC/Hydro Growers: a few days
    If a hydro or DWC grower switches their pond to plain water, the plants practically have direct access to almost zero nutrients. Despite this, to avoid early yellowing, a hydro grower will typically only flush their plant for a few days before harvest.

What Happens After Flushing?

You are taking the additional time after the bud is harvested to heal the bud to its full potential. Over the hard tip, a successful treatment will slash even more, eliminating things such as excess chlorophyll. You’ll be shocked at the difference this little effort will create with your produce. In the first inhalation of that silky smooth smoke, which reaches the back of your throat as soft as sugar, all of your hard work will show. It is smooth nature at its best. You can improve your cannabis output by simply adding water!

When Not to Flush Your Cannabis?

The only time you aren’t allowed to flush is when you expand in modified organic soil. That is because all the nutrients the plants need to survive already are in the soil. You will sweep out and destroy the fragile environment by draining the land, which you have worked so hard to grow itself in soil. Moreover, during waterings, such plants nearly always receive pure water. In this climate, plant uptake of nutrients is normal, abundant, and quick for the plant to absorb.


Although there is still some controversy among even seasoned farmers as to whether flushing is crucial, anybody who has ever tried to treat a weed crop grown with traditional plant foods or fertilizers has obviously discovered that flushing is important from personal experience. So it is a good thing to know how to flush marijuana plants. Flushing pot plants during growth stages, after nitrogen burning or lockout events, and enhancing plant safety and the consistency of growers’ goods before the final harvest.