One of the most common questions in growing and cultivating marijuana, whether for personal use or medicinal use, is the sudden change in leaf or pistils turning brown of your marijuana plant. We refer to healthy marijuana plants as cannabis plants that have an overall healthy disposition with green leaves and bright white pistils.
This sudden change in the color of marijuana plants especially the leaves can be due to the following:
Marijuana plants need a number of nutrients to be able to grow healthy and to create larger and juicier buds. These nutrients are commonly found in soil and adding fertilizers and supplements will be able to improve the levels of these nutrients easily. A soil sample test can be done if leaf discoloration, wilting and folding happen more often.
- Boron – Improper growth of plant leaves combined with discoloration and drying out are indications of plants suffering from boron deficiency. This is a typical condition of plants located in a dry and less humid environment.
- Calcium – Appearance of dead blotches, awful crinkles, unusual spots and shedding of layers of stems and leaves are implications of calcium deficiency. These symptoms likely occur in fast-growing leaves as well as in freshly developed leaves.
- Copper – When the leaves start to turn dark and its tips turn white or yellow, it is possible that your cannabis plants are experiencing copper deficiency. The metallic or shiny sheen appearing on leaves making them stiff and curve downwards is an indication that the deficiency is getting worse.
- Iron – While experiencing other mineral deficiencies, iron deficiency may simultaneously occur. This could also occur as a result of plant experiencing too much stress. A common indication is the turning of leaves into yellow which gets back to normal as soon as the plant is cured.
- Magnesium – The appearance of the yellowish color on the edges and the veins of the leaves is a manifestation that your cannabis is infested with magnesium deficiency. If not cured, this could lead to the falling off of your plant’s lower leaves.
- Nitrogen – Just like any other condition, marijuana plants experiencing nitrogen deficiency have their leaves turn yellow.
Nutrient deficiencies should be monitored and corrected as soon as possible. Using an organic nutrient solution is the best way to go to make sure that you are not using chemicals that can harm your plants. It’s also important to protect your plants from stress which could contribute to discoloration of leaves and other plant parts.
There are terrible pests that can cause wilting and discoloration of the leaves, pistils, and stems of cannabis plants. One of the most popular is the spider mite, a flat spider-like bug that has a very voracious appetite. A spider mite has strong jaws that can bite through the undersides of leaves to suck the precious sap inside. It can consume the whole plant when left unnoticed for a few days and it can even devour a massive crop in just a single week. The eggs it’s females produce can reach up to a hundred and are ready for attacking when hatched.
Pests such as spider mite can leave a large bunch of marijuana plants useless. As it eats and thrives on the leaf of the plant, it can cause wilting and discoloration since the leaves basically does not have any remaining insides to grow and thrive. Aside from this, spider mites can weave a thick web that can envelop leaves, pistils, stems, and branches of the plant making buds useless.
Spider mites should be removed by spraying water on it. As much as possible, be diligent and simply use a water bottle sprayer and avoid using hazardous chemicals and insecticides because these can affect the quality and overall yield of the plant. You may also use organic products and currently the most popular to use is neem room to remove these mites. Purifying your grow room is also necessary after your harvest is over to completely eradicate these.
Rot or mold
Bud rot or mold can be due to very cold temperatures, high humidity, and poor air circulation. Damp places with humid conditions can lead to the growth of mold which can totally affect bud growth and development. It’s important that growers keep a close eye on their buds and act as soon as he notices something odd. This condition can affect the largest colas and therefore all affected buds should be removed ASAP to prevent the spread of the condition to other plants.
Yellow leaf spots
Aside from completely turning yellow or brown, the leaves of marijuana plants can also turn yellow or develop yellow spots due to a fungus or bacteria that attack the plants. This is common in warm and wet weather and can start at the bottom of the leaves. Spots have uniform shapes with darkened borders and obvious hard growth in the middle, which is where a spore is located. These yellow spots can turn brown over time. Removing affected leaves is one way to stop the infestation and to add mulch underneath your plants to stop the spores from spreading to other plants in your crops. Fungicides are also available to kill these yellow spots as soon as these appear.
Cannabis plants can only take a certain amount of heat and light and excess of these can lead to discoloration of leaves (yellow or brown changes in color), curling and folding of leaves inward could all mean heat stress. Indoor growing of cannabis can lead to heat stress when the temperature inside the grow room, as well as the humidity, can be too overwhelming for plants. Plants that stretch towards the light source can also suffer from heat stress resulting in discoloration of the leaves. Outdoor growing also predisposes cannabis plants to heat stress, especially if the weather is too hot and dry and when there is not enough water.
Growers must deal with heat stress seriously as it infest oppressively at the critical which is the flowering stage since it is where your cannabis plant ceases to grow its leaves. Extreme heat damages the buds and even discolors the pistils that will result in lesser yields.