Solving Marijuana Plan Leaf Curl/Cupping Problems

Plenty of first time and experienced marijuana growers will suffer at some point in their cannabis growing career marijuana plants that begin to show leaf damage.

Often they write emails or post on forums.

“Help, my leaves are cupping and the leaf edges are turning brown!”

or

“My plant's leaf tips are curling down and turning black ....what's wrong?”

Unless another marijuana grower inspects the damage a true assessment might not be possible. It's hard to tell "exactly" what the culprit is. Unfortunately the “solution” the marijuana grower chooses many times is not the right one.

A misdiagnosis only serves to make matters worse by promoting further decline.

The ultimate and correct solution is in the hands of the marijuana grower.

Here are some common problems when marijuana leaves are curling.

  1. Too much marijuana fertilizer
    The most common cause of marijuana leaf cupping aka leaf margin rolling, leaf margin burn, and leaf tip curl/burn is overzealous use of marijuana plant food. In relationship to factors such as marijuana plant vigor and rate of growth. Leaf burn is often the very first sign of too much marijuana fertilizer.
    A hard, crispy feel to the marijuana leaf frequently occurs as well, as opposed to a soft and cool feel of a happy pot leaf. Back off on the amount and/or frequency of using marijuana fertilizer. Too much marijuana fertilizer can also burn the roots, especially the sensitive root tips, which then creates another set of problems. Note - as soil dries, the concentration of the remaining salts rises further exacerbating the problem.
  2. High Heat
    The marijuana plant is losing water via it’s leaves faster than what can be replaced by the root system. The marijuana leaf responds by leaf margin cupping or rolling up or down (most times up) in order to conserve moisture. A good example is reflected by the appearance of broad-bladed turf grass on a hot summer day, high noon, with low soil moisture levels - the leaf blade will roll upward/inward with the grass taking on a dull, greyish-green appearance. Upon sunrise when moisture levels have returned to normal, the leaf blade will be flat. Lower the heat in the marijuana grow-op and concentrate on developing a large robust root system. An efficient and effective root system will go a long way to prevent heat induced pot leaf dessication or marijuana leaf margin curling. One short episode of high heat is enough to permanently disable or destroy leaf tissue and cause a general decline in the leaves affected, which often occurs to leaves found at the top of the cannabis plant. The damaged pot leaf (usually) does not fully recover, no matter what you do. Bummer in the summer. One can only look to new growth for indications that the problem has been corrected.
  3. Too much light
    Yes, it’s true, you can give your marijuana plant too much light. Cannabis does not receive full sun from sunrise to sunset in its natural state. It is shaded or given reduced light levels because of adjacent plant material, cloudy conditions, rain, dust, twilight periods in the morning and late afternoon, and light intensity changes caused by a change in the seasons. Too much light mainly serves to bleach out and destroy chlorophyll as opposed to causing marijuana leaf cupping, but it often goes hand-in-hand with high heat for indoor marijuana growers. Turn down the time when the lights on in your marijuana grow room. If you're using a 24 hr cycle, turn it down to 20 hrs. Those on 18 - 6 marijuana growth cycle can turn their lights down two or three hours. Too much light can have many adverse effects on marijuana plants. Concentrate on developing/maintaining an efficient and robust root system.
  4. Over Watering
    For marijuana growers using soil, this practice only serves to weaken the root system by depriving the roots of proper gas exchange. The marijuana plants roots are not getting enough oxygen which creates an anerobic condition inducing root rot and root decline with the end result showing up as leaf stress, stunted growth, and in severe cases, death. Over watering creates a perfect environment for damp-off disease, at, or below the soil line. Many times marijuana growers believe their cannabis plant is not getting enough marijuana fertilizers (which it can't under such adverse conditions), so they add more marijuana fertilizers. Making the problem worst. Not better. Often problem 1 and 4 go together. Too much marijuana fertilizer combined with too much water. Creating plenty of marijuana plant problems.
  5. Not Enough Water
    Not only is the marijuana plant now stressed due to a low supply of adequate moisture, but carbohydrate production has been greatly compromised (screwed up). Step up the watering frequency, and if need be, organic marijuana growers may need to water from the bottom up until moisture levels reach a norm throughout the medium. One of the best methods in determining whether a marijuana plant requires watering is lifting the pots. The pots should be light to lift before a water session. After watering the marijuana plants lift the pots to get an understanding how heavy they've become fully watered. If the pot feels light to the lift - it’s time to water. Don’t wait until the soil pulls away from the side of the pot before watering. And of course, leach, once in a while to get rid of excess salts. These are the five most common problems marijuana growers encounter when growing cannabis. Correcting the problems early will save the marijuana plants, but may reduce overall yield. With practice and experience these problems are easily overcome which will then enable the marijuana grower to produce fantastic marijuana plants. With heavy yields.

Continue reading here: Do Marijuana Fan Leaves Get Trimmed

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Readers' Questions

  • timothy
    Why are my nerve plant leaves curling?
    6 months ago
  • There are several reasons why your nerve plant leaves may be curling:
    1. Underwatering: If the soil is too dry or you are not providing enough water to the plant, the leaves can curl as a defense mechanism to retain moisture.
    2. Overwatering: On the other hand, overwatering can lead to root rot, which can cause the leaves to curl due to damaged roots.
    3. Low humidity: Nerve plants prefer high humidity environments. If the surrounding air is too dry, the plant may curl its leaves to minimize water loss.
    4. Insufficient light: Lack of sufficient light can cause the nerve plant to become weak and its leaves to curl. These plants prefer bright, indirect light.
    5. Pests or diseases: Infestation by pests, such as spider mites or mealybugs, can cause stress to the plant and lead to leaf curling. Additionally, certain diseases, like leaf spot or bacterial infections, can also result in curled leaves.
    6. To determine the specific cause of leaf curling, it is important to assess the watering routine, humidity levels, lighting conditions, and examine the plant closely for any signs of infestation or disease. Adjusting these factors accordingly can help resolve the issue.
    • Lukasz
      Why are my canna leaves curling?
      6 months ago
    • There could be several reasons why your canna leaves are curling:
      1. Overwatering: Cannas prefer well-draining soil, and overwatering can lead to root rot and leaf curling. Make sure you are allowing the top inch of soil to dry out before watering again.
      2. Underwatering: On the other hand, if your cannas are not receiving enough water, their leaves might curl and become wilted. Ensure that your plants are receiving adequate watering, especially during hot and dry periods.
      3. Environmental stress: Cannas are sensitive to extreme temperatures and fluctuations. High temperatures or cold drafts can cause leaf curling. Ensure your plants are located in a suitable environment with stable temperatures.
      4. Nutrient deficiency: Lack of essential nutrients such as nitrogen, potassium, or magnesium can cause leaf curling. Consider fertilizing your cannas with a balanced fertilizer according to the package instructions.
      5. Pest or disease infestation: Certain insects like aphids, spider mites, or thrips can cause leaf curling. Check for any signs of pests and treat accordingly using insecticidal soap or neem oil. Additionally, diseases like fungus or viruses can also lead to leaf curling. Remove and destroy any infected leaves and treat with appropriate fungicides if necessary.
      6. Genetic factors: Some canna varieties may naturally have curled or twisted foliage as part of their genetic characteristics. If the curling is uniform and consistent across all leaves, it could be the natural growth habit of your specific canna variety.
      7. It's essential to closely examine your plants and consider these factors to determine the cause of leaf curling. Adjusting watering practices, providing proper care, and addressing any potential issues should help restore the health of your canna plants.
      • Minna
        Why are my weed leaves drooping?
        8 months ago
      • There could be several reasons why your weed leaves are drooping. Some common causes include:
        1. Lack of water: Drooping leaves are often a sign of underwatering. Make sure you are providing enough water to your plants and ensure proper drainage.
        2. Overwatering: Surprisingly, overwatering can also lead to drooping leaves. It can cause root rot, which prevents the roots from absorbing enough water and nutrients.
        3. Nutrient deficiencies: Lack of essential nutrients like nitrogen, potassium, or magnesium can cause leaves to droop. Consider using a balanced fertilizer or adjusting your nutrient supplementation.
        4. High temperatures: Heat stress can cause plants to droop. Ensure your plants have proper airflow and are kept in an appropriate temperature range.
        5. Pest or disease infestations: Some pests, such as aphids or spider mites, can cause drooping leaves. Certain diseases can also lead to leaf drooping. Inspect your plants regularly for any signs of pests or diseases.
        6. Light exposure: Insufficient or excessive light can impact the health of your plants. Ensure your plants are receiving the correct amount of light for their growth stage.
        7. It's important to troubleshoot and identify the specific cause of your plants�
        8. 39; drooping leaves to provide the appropriate solution.
        • maria
          Why are the edges of my cannabis leaves rolling up?
          10 months ago
        • This is a sign of over-watering your cannabis plants. Too much water is causing the plant to dehydrate, forcing it to curl up its leaves to prevent further moisture loss. Make sure you are properly watering your plants and that the soil is draining well.
          • Attilio
            What causes cannabis leaves to be cupping?
            1 year ago
          • Cupping of cannabis leaves is usually caused by an imbalance in the plant’s environment. Too much moisture, insufficient light, and poor nutrient availability can all be contributing factors. In many cases, cupping can be managed through simply adjusting the environment the plant is in.
            • sara barth
              Why do weed leaves curl up?
              1 year ago
            • Weed leaves curl up when they are under stress, such as from heat, drought, or pests. Curling is part of the plant's defense mechanism as it helps to block out too much sunlight, retain some water, and reduce the damage inflicted by pests.
              • lena
                Why are my weed plants leaves curling up?
                1 year ago
              • There are several reasons why cannabis plants’ leaves may be curling up. It may be due to high temperatures, inadequate watering, over-fertilization, or deficiency of certain nutrients. It is important to determine the cause in order to provide the necessary treatment.
                • donald allen
                  Why are my weed leaves curling?
                  1 year ago
                • There could be several reasons why your weed leaves are curling. It could be an issue with the environment, such as too much heat, too much light, or not enough water. It could also be caused by an insect infestation, nutrient deficiency, or disease. If you think it might be an environmental issue, try adjusting the temperature, light, and water and see if that helps. If you think it might be a pest problem, consider using an insecticide or contacting a professional for help. You can also try applying a nutrient fertilizer to the soil to help with any nutrient deficiencies. If you suspect a disease, it's best to contact a professional for advice.
                  • grimalda
                    What causes cannabis leaves to curl?
                    1 year ago
                  • Cannabis leaves can curl due to a combination of environmental factors, such as temperature, light, moisture, and humidity. These changes in the environment can cause the plant to become stressed, resulting in curled leaves. Additionally, nutrient deficiencies, pests, and diseases can also lead to leaf curling.
                    • Roman
                      Why are my cannabis leaves curling?
                      1 year ago
                    • Cannabis leaves curling can be caused by a number of environmental and nutritional factors. The most common causes are heat stress, light stress, nutrient deficiencies, and pests. Heat stress usually results from temperatures that are too high, while light stress is caused by too much light. Nutrient deficiencies can be caused by an imbalance in your nutrient mix or lack of necessary nutrients. Pests can also cause leaf curling and should be monitored closely.
                      • weronika
                        Why are my marijuana leaves curling?
                        1 year ago
                      • Marijuana leaves can curl for a variety of reasons, including under- or over-watering, nutrient deficiencies, temperature extremes, pests, and diseases. It is important to monitor the plant closely and provide the correct soil, nutrients, water, and temperature to prevent curled leaves.