So what is flushing? A lot of us know it’s what you do right before flowering and right before harvest, but what it does may not be well known. Sure, we hear flushing your plants helps take out the nutrients, but what does that even mean? To start, flushing a plant is the process of feeding you plants nutrient-free water instead of the nutrient-rich mixture it’s received most of its life. Flushing helps your plants use up, burn off, and get rid of salts and nutrients built up while growing. If you overfeed your plants and they get nutrient burn, flushing will help your plant use and/or waste the nutrients it needs so that it can keep growing properly. While flushing is helpful, it’s not going to breathe tons of life into your plants. Flushing alone won’t necessarily make your harvest taste or smell better. The overall quality of your harvest is going to be determined by how well the plant was grown and how well it is harvested, cured, and stored.

What Flushing Does (and Doesn't) Do

Some growers believe that flushing is absolutely 100% necessary for a smooth, clean, and aromatic harvest. However, in opinion polls from several growers around the world, some growers don’t flush a single time and their harvests are fabulous. What does that mean for you?
Watering plants
That means it’s up to you- not the community or fellow gardeners, but you- to determine whether you want to flush or not. If you’re thinking, “No duh, everything I do in my garden is up to me!” you’re completely right. What we mean is if you choose not to flush your plants be prepared to take extra care of them. Why? Well, there are a few reasons:
  • Flushing is helpful for growers who use lots of nutrients in their feeding regimen
  • Flushing will help clear out some of those nutrients and minerals your plant’s still storing
  • Flushing also helps the absorption of the remaining sugars in your plants, which will help their flowers and fruit health a little more before they’re chopped down.
  • Flushing’s also a good idea between the vegging and flowering stage to help free plants up to take in flowering nutrients
So while flushing can add to the overall health of your plant that will, in turn, make for a tasty harvest, it's not completely necessary A highly experienced grower who has very few- to no- nutrient deficiencies or overfeeding to correct usually don't flush because they know how much their plants can intake. Either that, or they honestly just don't want to because flushing will not add to the taste, smell, or effects of the harvest. So should you be flushing? If you’ve got your feedings down to a science and are careful not to overwhelm plants with nutrients, flushing isn't completely necessary. If you’re not pinpointing exact feedings or you use lots of additives and supplemental nutrients, you'll want to flush your plants.

When and How to Flush Your Plants

There are three main times you’ll want to flush your plants: 1) When a plant is overloaded with nutrients. When nutrient lockout occurs the tips of your leaves will turn yellow and brown, then dry up and possibly die. Indicative of overfeeding, you’ll want to flush your plants when there are simply too many nutrients for the plant absorb easily. 2) Between the vegging and flowering cycle. This will help prepare your plants to take in flowering nutrients by absorbing and clearing out those grow/vegging nutrients. While not 100% necessary, this will help transition your plants into a brand new feeding plan. 3) You guessed it- around harvest time. Now, this will be different from plant to plant and from medium to medium. Some plants are flushed within two weeks like soil plants, whereas other plants flush for only 2-3 days like when you grow hydroponically. No matter when your plants call for it, flushing them will help any nutrients left in your plants to be either absorbed or wasted.
Now, executing a flush can be done in one of two ways: either by using straight pH’d water or using clearing/salt leaching solution. While the goal of both techniques is the same, using a solution will help break down leftover minerals to use them or lose them. Using only water will help make nutrients in your plants available for absorption or waste. We should note that while the goal of flushing is to get everything out of your plant, understand that it’s virtually impossible to detect how much of a particular nutrient/mineral is present in a plant. That said, when you choose to flush, don’t break your back trying to get 0 ppm, just get as close to it as you can to assure that your plants have absorbed what they can and waste what they don’t.

1 comment

Anthony Williams

Very helpful explained well answered all my questions I been looking for in the past few days

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