Guide for flushing marijuana plants

Published Mar 5, 2019 01:55 p.m. ET

If you are new to growing than you may not have heard of flushing cannabis. The term itself sounds strange but what it means is to stop feeding your cannabis plants extra nutrients or fertilizer and only provide water for a certain period. This is done before harvest, in cases of a nutrient lockout, and in between growing cycles.

When to flush plants before harvest

There are three different scenarios in which a grower should proceed with flushing of marijuana plants.

If you are new to growing than you may not have heard of flushing cannabis. The term itself sounds strange but what it means is to stop feeding your cannabis plants extra nutrients or fertilizer and only provide water for a certain period. This is done before harvest, in cases of a nutrient lockout, and in between growing cycles.

When to flush plants before harvest

There are three different scenarios in which a grower should proceed with flushing of marijuana plants.

  1. Before harvesting
    Before you decide to harvest you should always be flushing marijuana plants for approximately 2 to 4 weeks. This is to rid the cannabis flower of any impurities including fertilizer that can affect the taste and toxicity of the end product.

  2. Transitioning through cycles
    There are three different stages of growth, and each one requires a transitioning of nutrients cycles or fertilizers. In between stages is when the least growth happens and is the best time to be flushing cannabis plants. By completely stopping all additional nutrients and watering slightly more than usual you will force the old nutrients out which will allow the plant to take in much more once you begin again and will enable it to use the extra vitamins more efficiently.

  3. Nutrient lockout
    Inadequate ph levels often caused by the over fertilizing of cannabis is the third time growers will be found flushing marijuana plants. Ph levels that are too high or too much salt will prevent proper nutrient absorption resulting in a nutrient lockout. Flushing cannabis can restore the plant’s ability to take in new essential nutrients and will also fix soil ph imbalances.

How to flush soil grown marijuana plants

Flushing marijuana plants is relatively simple. It is just using water to give your plant a fresh start or clean ending as needed.

  1. Before harvesting
    To perform a cannabis flushing before harvest, you will completely stop giving any additional nutrients or fertilizers to the plants for at least two weeks. During this time you will continue to water generously every single day. Each time you water you want to thoroughly saturate the soil and then do the same thing again 15-20 minutes later.

  2. Transitioning through cycles
    No matter which nutrient or fertilizer you choose there will be a transitioning period where the feeding schedule you follow will change. Performing marijuana flushing once a day by completely soaking the plant’s soil once, and then again 15-20 minutes later twice a day will push old nutrients out of the cannabis plant’s system. Allowing it to be able to take in and flourish off of the best nutrient for its current phase of growth.

  3. Nutrient lockout
    A nutrient lockout is when a marijuana plant begins to refuse any new nutrients. Usually caused by overfeeding and over fertilizing creating a toxic environment for the plant. Flushing cannabis using water containing a ph balance of 6.0 to 6.8 is most efficient for treating a nutrient lockout. Flushing marijuana plants twice a day for one or two weeks should be enough to restart your plant’s growth. Setting it on a much healthier path with better chances for the future.

How to flush hydroponic plants

Hydroponics require a shorter flushing cycle but are essentially the same thing.

Before Harvesting- Flushing for hydroponics before harvesting is as easy as removing any added nutrients from your daily feeding regimen for seven days. Since hydroponics is a water-based growing method, removing the majority of your water and replacing it with fresh additive-free water is necessary once a day for seven days.

Transitioning through cycles

Transitioning through cycles with hydroponics is also fairly straightforward. Withhold all fertilizers and nutrients for seven days while flushing marijuana plants twice daily with new water.

Nutrient lockout

When faced with a nutrient lockout you will need to be flushing cannabis plants with 5.5 to 6.5 ph level water twice daily for the full seven days. This water should replace the water you would typically give.

When to stop watering weed plants

Flushing marijuana plants are all about water. Watering should never completely stop but using the correct ph levels and only performing the flushing for as long as set out here is necessary. Too much flushing or flushing cannabis at the wrong time can stress a plant out and actually, end up doing more harm than good by stunting the plant’s growth.

To be sure of success

Wondering how to tell if the flushing cannabis plants you completed has been successful? First, of course, is visual health. If the plant appears to be doing better with green leaves or more growth than you will likely succeed. If you want to be entirely certain, then there is also the option of strips the will test the total dissolvable fluids (TDS). The strips are used by collecting a sample of water that runs out of the bottom of the pot. You will want the TDS level of water from the pot to be the same as what you are using to water with. Once those numbers match up a flush has been successfully performed.  

Author

Related posts