But we certainly can help you. Specifically to correctly identify most of the common causes for yellow leaves. Moreover, we have included helpful tips to treat ailing plants. Plus simple pro tips and tricks. Any home grower can implement our advice to avoid cannabis plants’ leaves turning yellow. Now let’s get into the specifics.
Indoor cannabis plants grown under artificial lights must be perfectly positioned and lamps must be in just the right distance above the canopy for best results. When lamps and reflectors are too close to the flowering tops, buds and leaves will be yellow and brown as the light is too intense. This is very much a top down problem.
Treatment: Make sure to hang your grow lights as per the manufacturer’s instructions. Adjust as plants progress and use a tape measure for precision. These days there are so many new grow light technologies on the market with their own nuances, you really must stick with the manufacturer’s guidelines to position the light in the sweet spot.
Essentially when the pH of your nutrient solution strays above or below the particular sweet spot for your substrate, it prevents complete absorption of all the elements of the solution. Roots are starved of certain nutrients and micronutrients as the incorrect pH causes a lockout.
Again, plants need just the right nutrients at the right time. Read the dosage instructions on the label of every bottle of fertiliser before adding to water. Furthermore, we highly recommend you consult the website of the brand of nutrients you are using as most feature custom charts and feeding schedules.
Treatment: Monitor the plant’s post feeding behaviour closely. Use one of the measures above to more accurately gauge when to water to prevent recurrence. Too much water can lead to root rot. Too little water will stunt growth. Keep a grow diary if you must and try to get into a routine as the grow progresses.
Treatment: Indoor growers need to turn up the air conditioning and ensure intake and outtake fans are powerful enough for the size of the grow room. Again, we strongly advise consulting the fan manufacturer’s website for performance specifications. Outdoors the best growers can do is construct a simple shade and hope the heatwave is short-lived.
No grower wants to see yellow leaves. Withering plants in the grow op are a miserable sight. Unfortunately not every cannabis crop grows trouble free. This can be due to incalculable reasons. It can be anything from grower errors to invasive microorganisms. Of course, we cannot provide you with a surefire silver bullet solution for every potential cannabis plant malady. We’re cannabis writers, not clairvoyants.
Temperatures below 10°C will cause the leaves of the majority of cannabis leaves to yellow. Some will even take on purple and bluish tones. Sure, this is a fantastic bonus in the final phase of bloom with some strains, but to be avoided early in the grow.
Are you seeing yellow leaves in your cannabis garden but can’t figure out the cause? This blog just might save your marijuana.
If you notice yellowing toward the top of the plant (specifically, nearest the light source), your plants are likely suffering from light burn. Light burn can happen in temperature-controlled environments as easily as those in high-heat if the leaves get too close to the lights. We liken this to getting a sunburn on the ski slopes.
The roll of chlorophyll is to absorb sunlight and transform it into energy via a process called photosynthesis. When plants have ample access to resources, chlorophyll thrives. When plants are stressed, however, the chlorophyll begins to degrade revealing the yellow carotenoids below.
The first thing you should do when cannabis leaves start to turn yellow is to measure the pH of your grow medium (soil, water, rice hulls, expanded clay, etc.). That’s because an improper pH balance – whether too high or too low – can actually block nutrient absorption.
If your marijuana leaves are turning yellow, don’t panic! This is just your plants’ way of telling you something is wrong. It is up to you to determine what that is so you can treat the problem without making it worse.
Temperatures outside of the ideal range of 70 to 80 degrees Fahrenheit also risk discoloration and curl leaves. These oddities are most common in leaves toward the top of the plant and can easily be remedied with a fan (if too hot) or root insulation (if too cold). We also recommend growing plants off a cold cement or tile floor; use a milk crate or stool to raise them off the ground when necessary.
Note that carotenoids cannot directly transform light into energy via the photosynthetic pathway and must pass it onto chlorophyll to finish the job. Therefore, while a minor yellowing leaves will not stop photosynthesis, excessive or unaddressed yellowing can either stunt plant growth or kill the whole thing entirely.
Fungus gnats, which live in wet soil and feed off roots, are the most common pest in cannabis gardens. The best way to rid your garden of fungus gnats is to restrict watering until absolutely necessary (this prevents the gnats from laying eggs in the soil). A general best practice is to only water your plants when the top inch of soil is dry.
Iron deficiency can also cause yellow leaves, though this occurs on new growth only (old leaves remain bright green). Iron deficiencies are also caused by improper pH and can be remedied with iron-fortified fertilizers. When iron is given to deficient plants, the leaves should start to turn green beginning along the edges until the whole leaf is bright green.
Leaves are made up of plant cells. Plant cells are made up of organelles called chloroplasts. These chloroplasts contain pigments that absorb different wavelengths of light. Though most of these pigments are green chlorophyll, other pigments are also involved. Most notable are the yellow and orange carotenoids that hide under the dominant chlorophyll.
Does your cannabis grow have plants with yellow leaves? Yellowing marijuana leaves can indicate a variety of common ailments. Keep reading to learn more about cannabis plant health and tips to overcome yellow leaves.