lady pruning nutrient deficient plant

Stoney Tark edited on: November 08, 2023 8 minutes read

Nutrient deficiencies can be a common issue for cannabis growers, but sometimes the underlying problem is nutrient lockout. Nutrient lockout occurs when plants are unable to absorb nutrients through their roots, leading to deficiencies and stunted growth. In this article, we will discuss how to identify and treat nutrient lockout to ensure a healthy and abundant cannabis harvest.

What is Nutrient Lockout?

Nutrient lockout happens when a plant is unable to take up nutrients from its environment, even if those nutrients are present. This can result in nutrient deficiencies, which manifest as discolored foliage and stunted growth. The nutrients needed by the plant are there, but they are inaccessible due to the lockout.

Causes of Nutrient Lockout

There are several causes of nutrient lockout, including:

  1. pH imbalance: pH imbalance is the most common cause of nutrient lockout. Nutrients are only available to plants within certain pH ranges. If the pH of the soil, water, or nutrient solution falls outside the ideal range (5.8-6.5 for cannabis), the plant cannot absorb the nutrients, leading to lockout.
  2. Overfeeding: Overfeeding is another common cause of nutrient lockout. Plants can only absorb a certain amount of nutrients, and any excess remains in the soil. Continuous overfeeding or the use of premixed chemical fertilizers with high sodium content can result in salt or nutrient buildup around the plant's roots, interfering with nutrient absorption.
  3. Nutrient imbalance: Nutrients can interact with each other, affecting their availability to plants. For example, organic matter like humus can coat and interfere with phosphorus binding sites in the soil, increasing phosphorus availability. Conversely, poorly prepared fertilizers or soils with nutrient imbalances can decrease nutrient availability, leading to lockout.
  4. Overwatering: Overwatering can contribute to nutrient lockout by causing salt and mineral buildup in the plant's growing medium. This buildup can interfere with nutrient absorption over time.

signs of deficiencies

Signs of Nutrient Lockout

Nutrient lockout does not have its own specific signs or symptoms, but it leads to nutrient deficiencies, which can be identified through the following signs:

  • Discoloration of leaves, such as yellowing or spots. Some deficiencies may also cause purple or red stems.
  • Curled, twisted, or distorted leaves.
  • Stunted or abnormal growth.
  • Dying leaves.

How to Prevent Nutrient Lockout

Preventing nutrient lockout is crucial for maintaining healthy cannabis plants. Here are some tips to help you prevent nutrient deficiencies and lockout:

  1. Maintain proper pH levels: Regularly test and adjust the pH of your water, nutrient solution, and soil. Aim for a pH range of 5.8-6.5 for cannabis, depending on your growing medium.
  2. Avoid overfeeding: Follow a balanced fertilization schedule and avoid overfeeding your plants. Understand the nutrient requirements of your specific strain and adjust your feeding accordingly.
  3. Use high-quality nutrients: Invest in high-quality fertilizers that provide a balanced blend of essential nutrients. Avoid cheap or low-quality products that may contain impurities or imbalances.
  4. Proper watering practices: Avoid overwatering your plants, as it can lead to nutrient buildup and lockout. Allow the growing medium to dry out slightly between watering to prevent waterlogged conditions.
  5. Consider organic growing: Organic soils and nutrients are less likely to cause nutrient lockout. The natural composition of organic matter promotes a balanced nutrient uptake by the plants.
  6. Regularly monitor plant health: Keep a close eye on your plants and regularly inspect them for any signs of nutrient deficiencies or lockout. Catching and addressing issues early can prevent further damage.

By following these preventative measures, you can minimize the risk of nutrient lockout and ensure healthy and thriving cannabis plants. For all the growers out there and possible future growers! In case something happens with your grow. We've prepared a free pack of seeds for all of you. Use the following code and receive a free pack of Original Glue! Code: SD9SKFD2. The code is valid until: November 15, 2023.


Nutrient lockout can be a significant problem for cannabis growers, but with proper prevention and timely treatment, it can be managed effectively. By maintaining pH balance, avoiding overfeeding, using high-quality nutrients, practicing proper watering techniques, considering organic growing methods, and monitoring plant health. You can prevent nutrient deficiencies and lockout in your marijuana plants. Remember that prevention is key to a successful harvest. Happy growing!

Stoney Tark

Stoney Tark has been involved with cannabis for over 15 years. During this time, he has become head writer for the long-standing magazine; Soft Secrets, a position he has held for the last ten years, alongside writing for every other main publication.

Author of Stoney Tark’s Top Tips on Growing Cannabis, host of The Roll Models Podcast, breeder and sponsored by SANlight LED. Stoney is well versed in many systems and methods of growing, including, Organics, Hydroponics, Breeding, and Hash production. 

Well known in the public eye for his easy-to-understand and detailed breakdowns of all things related to cannabis. 

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