Much like us, cannabis plants need the proper nutrients, sunlight, and healthy environments to properly grow and flourish. However, if something is out of balance, whether it is the pH, a lack of nutrients, or a virus, your cannabis crop can show signs of suffering. Thankfully, cannabis plants are good at telling us what they are lacking. We only need to know how to listen and interpret the signs.

 

 

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Reading the Leaves

 

The leaves of a cannabis plant can tell us a lot about the plant’s health. If a plant has all the nutrients it needs and is in a healthy environment, its leaves will be a vibrant green color. Depending on the strain, this healthy shade may appear darker or slightly lighter than others. However, leaves that are part of an unhealthy plant can help cultivators identify what exactly is ailing their plant. 

 

For example, leaves that are darker in color than they should be can hint at a nutrient excess. When a plant is fed more nutrients than it needs, the leaves will turn dark green. Depending on the lifecycle stage the plant is in, this can be remedied. 

 

On the other hand, leaves that are paler than they should be can indicate a nutrient deficiency. It could also indicate the presence of a virus or viroid. While the color of the leaves can help point a grower in the right direction, they will have to consider other factors to determine what is ailing their plant.

 

Other ways the leaves of a cannabis plant can indicate an unhealthy state is by rust-colored spots, curling, or bite marks. Rust-colored spots, also called burn spots, can indicate nutrient deficiencies. Bite marks are a common indicator of a pest infestation. Curling can indicate a number of problems including viruses, viroids, and nutrient deficiencies. Similar to paling leaves, these signs can help determine what precisely is ailing your plants when considered in conjunction with other symptoms.

 

 

Understanding the Stems

 

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The stems of a cannabis plant can also give us some indicators of what is ailing our crop. Think of the stem as the connection between the leaves and bud of the plant and the roots. When one is ailing, it can impact the stem as well.

 

For example, botrytis can impact a stem by leaving it soft and squishy to the touch. According to the Pacific Northwest Pest Management Handbook, “Botrytis cankers develop to the point of limb breakage or stem splitting, especially if plant canopies are dense and heavy. Small, black sclerotia can develop within stem tissues.”

 

Stems can also provide evidence of nutrient excess or overwatering by displaying purple streaks along the stem. The darker the streaks, the more advanced the excess. If left ignored, the cannabis plant could produce lower yields and be susceptible to disease or pests. 

 

 

The Roots Tell All

 

The roots are the nervous system of the plant, taking nutrients from the soil and supplying them to the rest of the plant. When the roots are damaged in any way, the rest of the plant will suffer.

 

Healthy roots should appear white in color with spreading nodes. But if the roots are brown or grey in color, this could indicate a serious problem. Root breakage and stunted growth could also be an indicator. 

 

Overwatering, pests, viruses, molds, and viroids can all have a negative impact on the roots of a cannabis plant. Identifying the correct problem can be done by combining the symptoms of the roots with other symptoms the plant possesses.

 

 

Low Yield? That’s a Big Problem

 

If a grower ignores all the signs a plant has given them early on in its lifecycle, it can be no surprise that the yield of the plant is low. Low yields can mean a lack of revenue and hurt the business long-term, yet many growers experience this problem yearly.

 

Low yield can appear in a number of different ways. Some buds may appear smaller or more spaced out than the specific strain should be. Others may be light and fluffy rather than dense (this is often called Larf in the cannabis community). All of these phenomena contribute to a low yield.

 

While it is true that some strains are known to produce lower yields when compared to others, any strain can be subject to low yields. For example, Clementine is a sativa-dominate strain known to produce smaller buds more ideal for extraction whereas Animal Mint Cake, a hybrid strain, is known to pack on the pounds. However, both strains can experience low yields if the plants have experienced sickness or an overabundance of stress. 

 

 

Where to Learn More About Keeping Cannabis Plants Healthy

 

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Ready to learn more about how to keep a cannabis crop happy and healthy? Verne Bio has a wealth of information available in our Knowledge Center. We cover topics ranging from the latest viruses and viroids growers need to know about to cultivation tips and tricks. 

 

Readers can also get our content delivered right to their inbox with the Verne Bio newsletter. When readers sign up they can receive the latest articles, information about ongoing sales, and more. 

 

Learning about cannabis has never been easier when Verne Bio is in your corner. Our Knowledge Center is a valuable tool for growers of all experience levels. By continuing to expand your education about the cannabis plant, problems such as the ones listed above will become few and far between. What could be better than raising healthy and happy cannabis plants?

 

 

 

 

 

 

Works Cited

 

BossHog. “Marijuana Leaf Deficiency Chart.” 420 Life | 710 Life, 26 October 2021, https://420life.com/marijuana-leaf-deficiency-chart/. Accessed 23 September 2023.

 

Ocamb, Cynthia M., et al. “Hemp (Cannabis sativa)-Gray Mold (Botrytis Bud Blight and Stem Canker).” Pnwhandbooks.org, March 2023, https://pnwhandbooks.org/plantdisease/host-disease/hemp-cannabis-sativa-gray-mold-botrytis-bud-blight-stem-canker. Accessed 23 September 2023.