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A Beginner's Guide to Flushing Cannabis

A Beginner’s Guide to Flushing Cannabis

Imagine this: You’ve harvested your first beautiful buds from your plant. You’ve dried them, cured them, and they’re ready to smoke. Then when you try to spark up, you’re a little disappointed. Your joint won’t light well, and when it does, you end up coughing and spluttering. The taste is far from what you imagined.

Often, the unpleasant taste results from nutrients and minerals that most growers use to aid production. By flushing cannabis plants, you get rid of the additives to maximize your experience and enjoyment.

If you’re new to the world of growing cannabis, you may not be familiar with the term flushing weed. Don’t worry. We’ve put together the ultimate guide to know why, when, and how to flush marijuana plants.

What Does Flushing Cannabis Mean?

We use this technique to rid the plants of nutrients and minerals accumulated during the growing process. Flushing marijuana is straightforward, and all you need is water.

Be warned. You’ll have to keep on top of the process and perform it regularly during the growing period.

What is flushing weed?

The best way to flush your plants is by allowing large amounts of water to pass through the soil and then drain regularly. This process lets all the minerals and nutrients in the dirt wash away over time, leaving it nice and clean. You could try flushing cannabis with molasses or some other similar substance, however, for this article, we will mainly focus on good, old-fashioned water.

In many circumstances, we get told it’s the importance of removing minerals and nutrients. It might seem damaging, but it increases your yield and harvest quality a great deal. Because by removing these nutrients, you force your cannabis plant to use everything it has left,  leaving nothing to taint the bud before harvesting.

Why Is Flushing Cannabis Necessary?

Many experts consider flushing marijuana plants as an essential step. Failure to do so could affect the flavor. Of course, some believe the opposite and state that it’s counterproductive and doesn’t benefit growth.

Using this method can make a massive difference. Read some of the benefits below to help you decide.

Preventing a Nutrient Lockout

While you want your soil to be nutrient-rich, there’s such a thing as too many minerals, which results in ‘nutrient lockout’. This problem occurs when there’s an abundance of minerals in the soil that prevent the plant from soaking up more.

If you know how to flush weed properly, you can prevent a lockout and keep your cannabis healthy.

To Transition Between Growth Stages

Just as humans go through different growth changes, so does your cannabis. With each stage, your plant’s need for nutrients differs. During the vegetative stage, your weed will require different minerals than when it’s flowering. Flushing marijuana plants between the phases is necessary, boosting it to continue its journey.

When to Flush Cannabis Plants

There are three occasions when flushing weed works best and will have the most significant impact on your final product:

  • Nutrient excesses: When there are too many nutrients present
  • To Amend nutrients between growth stages
  • Around two weeks before you harvest your plant

Nutrient Excesses

However much we try to avoid a nutrient lockout, it’s something that happens. It can be the result of overfeeding your plant, not monitoring pH levels, or other stresses.

Whatever the cause, you need to put things right quickly because your plant isn’t getting the minerals it needs.

When to flush cannabis plants
A flush will help to wash away excess nutrients.

Ensure any soil is dry before watering weed again, so your plant has time to breathe and to avoid root rot. You can use a cannabis flushing solution to help rid your plant of additional salts and other minerals.

To Amend Nutrients Between Growth Stages

To help give your weed the boost it needs to kickstart the next development phase, perform a cannabis flush by clearing out old nutrients to make room for the new.

By removing all the old food from your plant, you’re clearing the path and making way for further development.

Two Weeks Before Harvest

The most crucial time for flushing marijuana plants is during pre-harvest. The timing here is essential. If your cannabis doesn’t use or break down the nutrient reserves, it can harm the flavor.

Even if you forget to flush during the rest of your plant’s life, don’t neglect it now.

Cannabis Plant Ready two Weeks before Harvest
Start your flush as soon as you see that all or most of the trichomes are cloudy.

Although flushing time for soil is two weeks, other mediums require less:

  • Rockwool or coco needs one week
  • Hydroponics needs one week or less

One of the biggest mistakes growers commit is flushing too early. This error can stunt the plant’s growth, cause lower potency because of fewer nutrients, and affect the bud’s appearance.

How to Flush Weed Plants 

Once you know when to start flushing cannabis, you’ll need to learn the process. Ensure you follow each step below to get the best results.

1. Prepare pH Amended Water

Cannabis flushing entails running pure water through the plant’s soil or another medium.

You’ll need to check the pH level of your H2O, though, to ensure that it’s between 5.5-6.5 for Hydroponics and 6.0-6.8 for soil.

This effort helps prevent a nutrient lockout and gives your plant a boost during growth transitions.

. Prepare pH Amended Water
Check the pH level of your H2O ensure that it’s between 5.5-6.5 for Hydroponics and 6.0-6.8 for soil.

2. Water Your Plants With No Nutrients

The idea of a cannabis flush is to wash away any excess nutrients. It only makes sense that you water your plants without any. Tap water is generally adequate to use as there are no added minerals, but be sure to test the pH whenever possible.

You need to fill the soil with as much water as possible, let it drain, and then repeat.

Water Your Plants With No Nutrients

3. Monitor Plants for Signs of Nutrient Problems

While your plants are growing, you’ll need to monitor them regularly to spot any issues early. Nutrient deficiencies can occur, but you can usually avoid this problem by feeding the plants promptly during the beginning of each growth stage.

You might also see yellowing signs on the leaves pre-harvest, which is nothing to worry about and is completely normal. Don’t let them go yellow all over, as this will hinder the plant’s ability to photosynthesize.

There’s not much point in adding more nutrients just before harvest to avoid yellowing leaves. All you need to do is carefully remove any yellow leaves as soon as possible.

4. Use a TDS Meter to Check Water Run-Off

If you want to ensure your marijuana flush was successful, you can use a TDS reader to test the water runoff’s purity.

You should compare the TDS reading of the pure H2O you’re flushing with to the water draining out. This way, you’ll see whether all the nutrients are washing away.

5. Harvest Your Plants 

Finally, it’s time to harvest your bud. Take time to cure your produce to its highest potential to reduce any harshness even further. Check for chlorophyll and make sure it’s all broken down; this can make a big difference.

Here you can find our step-by-step guide to harvest your cannabis plants.

All that’s left is to enjoy the silky smooth hit on the back of your throat. See if you notice once you try the well-flushed weed.

Flushing Cannabis in Soil and Hydroponics

Knowing how to flush cannabis plants is essential as the process differs from soil and hydroponics. The latter is much more straightforward.

Hydro growers need to drain their system and then replace the liquid with pH-balanced water. The process is also much quicker, often taking just two or three days.

This shorter timeframe is because once you switch the water supply, there’s no soil for nutrients to hang around, meaning the plant doesn’t have access to them.

Beware, though, that hydro growers’ plants can still be susceptible to root rot, which is where flushing agents for cannabis can come in handy. These contain beneficial root bacteria that can protect your weed right up until harvest.

Do You Actually Need to Flush Marijuana Plants?

There’s a bit of a debate between experienced weed flushers when it comes to answering this question. Some say that it doesn’t make much of a difference and is a cannabis flushing myth.

Plenty of growers have experienced nutrient lockout or root rot and could have benefited from a thorough weed flushing.

Cannabis buds

Some might deny the difference in taste, but it’s difficult to doubt the positive effects of flushing marijuana plants. It prevents nutrient lockout, helps boost transitions between growth stages, and gets your cannabis ready for harvest.

You can significantly improve your weed health when you know how to flush plants in soil, hydroponics, and other mediums.

When to Avoid Flushing Marijuana

It’s essential to note that there’s one instance when you need to avoid flushing, which is when you’re growing weed in amended organic soil. This type of dirt already has all the nutrients your plant needs for a healthy life cycle.

When you flood this soil, you can damage and ruin the complex ecosystem you worked so hard to develop. Your plants almost always get pure H2O when you water them, and they take in all the nutrients they need naturally in this growing environment.


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