No matter what marijuana plant problems you’re having, generally, there is a solution. Use the marijuana troubleshooting guide below and get your grow back on track.
White seeds are immature and tend to crush easily under very little pressure. If you’ve produced them, discard them. If you’ve bought them, contact your seed vendor for a refund.
Green seeds are immature, but if they don’t crush under pressure, they’re usable. Germinate and plant closer to the surface as they don’t contain the stored energy of darker, more matured seeds.
Some strains (mainly sativa) do not produce large seeds. Always use the largest seeds possible, but small seeds should germinate normally.
Brown, Slimy, Smelly Roots
This condition is generally known as root rot and is caused by a lack of oxygen. Growth will stunt and your plant will wilt. By the time this has happened your plant may be beyond repair. To try and save it, remove any smelly and damaged roots and rinse, allowing too dry before putting back in a clean medium and container.
Tightly packed Roots/Sprouting out the bottom of the container
The plant is root bound, which means the rooting system hasn’t enough room to grow. Transplant your plant to a bigger container, taking care not to break any of the roots and place on top of fresh medium. This should hopefully take care of your root marijuana plant problems.
Sparse rooting system
Depending on the age of the plant, this could be a result of the roots not getting enough oxygen. In soil, make sure you are using a well aerated medium or add air stone to your hydroponic reservoir.
Thin and frail/stretching stems
The most common cause is a lack of light. Your lights are either too far away or you’re not supplying them with enough Kelvin in vegetative growth. Move your lights closer and bury your plant deeper when transplanting.
Don’t panic, you can fix your plant. Use a piece of string to tie up and close the area, not pulling too tight so that you end up suffocating and damaging the plant. Support the stem while it’s healing to limit the stress.
Bending Stems/Buds too heavy
Lucky you. Make sure you support and tie up the branches to make sure they continue to flourish.
This could be down to a number of issues which include; over or under watering your plant, rotten roots, insect damage or toxic levels of nutrient build up. You will not be able to diagnose the marijuana plant problems through stunted growth alone, however, there will be one or two other tell tale signs that you should be able to find on this page which will help you put your plants growth back on track.
The plant’s leaves are a great indicator of when you’re having marijuana plant problems. Whether it’s a pest, disease, or a problem with nutrient levels, the leaves are a great indicator of a plant’s happiness. If you can’t see your specific marijuana plant problems here, use our more detailed pages for Pests and Diseases and Nutrient Deficiencies.
The most common cause of drooping leaves is over or under watering. Over watering is one of the most common marijuana plant problems for beginner growers. Check out our section on over and under watering plants here.
If the leaves are yellowing with no other symptons, the plant is probably suffering from a nitrogen deficiency. Check your pH levels* and add more nitrogen to your nutrient solution.
If the yellowing leaves are accompanied with browning tips which are dying back, then you may be over fertilizing. Flush your plants with clean water, using three times the volume of the container you’re growing in.
Yellowing leaves also occur on plants that are approaching harvest. This is completely natural and is your weed using up nutrients to produce resinous buds.
Pale Brown spots throughout leaves
This is either a phosphorous deficiency or a pest infestation. Refer to our pages on pests and diseases and nutrient deficiencies for more information.
Yellowing between veins
Is evidence of a Potassium deficiency. Check your pH balance and add to your water.*
Purple/Brown spots and/or dark green leaves
Indicates a phosphorous deficiency which will also stunt the growth of your plant. Check your pH balance and add to your water.*
White with green veins or pale yellow leaves
Signifies an Iron deficiency which is likely to be caused by incorrect pH levels. Check and correct your pH levels.*
Larger leaves yellow, pale new growth and brown tips on leaves
This is caused by a lack of calcium and magnesium. As always, check your pH levels as trace nutrients are likely to be locked out if this is outside of 5.8 and 6.8. Add a little dolomite lime (1tsp per gallon) or cal-mag to your water.
Edge of leaves brown and start to curl up with yellow or brown spots on leaves
It is likely that your plant is suffering from heat burn. This can be caused by having your plants too close to your lights as well as the grow room temperature exceeding 85°F (30°C). Use our guide on lighting to make sure you’re keeping your lights the right distance away from the plant and refer to our guide on Air Ventilation for tips on how to keep your grow room at optimal temperatures.
It goes without saying, that this is what we grow our weed for; the tasty, smokeable flowers of the marijuana plant. Most issues are solvable, but prevention is the best cure. Check out pages on Pests and diseases and nutrient deficiencies if your marijuana plant problems are not listed below.
Small flowers with Hard Bumps between pistils
Your plant is pollinated and there isn’t anything you can do. You can smoke the buds, but they won’t be as strong or tasty as sensimilla flowers. Check out our page on flowering on how to avoid this is the future.
Slow Growth and small buds
There are a number of things that could be going on; over-fertilizing, bad air circulation, insufficient light, poor rooting systems. Make sure that you follow our guidelines on indoor growing to maximise your bud growing potential.
White powder/Grayish spots on buds
This is gray mold and cannot be cured. Remove the infected bud(s), cutting them out an inch below the contaminated area. Take out of your grow room and destroy. This cannot be smoked as it’s very harmful. Gray mold will spread through your grow room like wild fire, spoiling your whole crop.
Leaf discoloration and dieback
If this is late in the flowering stage, it is nothing to worry about as it is just your plant using up it’s nutrients to produce big buds. If it is early (up to 6 weeks into flowering) check your pH and nutrient solution.* For details, use our guide on nutrients.
Pungent Odours from Grow Room
This is to be expected and means you are growing good, potent weed. Our page on Ventilation contains some tips on odor control.
White Pistils turning red or orange
This is nothing to worry about, and is a sign that your plants are only a few weeks away from harvesting.
Drying and Post Harvest
Once you have got to this stage, there are still things that can go wrong. Although it seems all the hard work is over, for the buds to reach their full potential, there is still an important process to follow.
The bud has been dried to fast. It takes time to get all the harsh tasting chlorophyll and sugars out of your weed. You can add citrus peelings to your bud or re-hydrate in a room with 80% humidity to start the curing process again, but you need to be more patient in future.
Buds full of mold/mildew
Air circulation in the drying and curing process was poor. You cannot save moldy bud and smoking it can seriously damage your health.
Buds taste and smell of hay
The buds were harvested too early. A long and slow cure will help, but your bud will never reach its full potential. Our guide on harvesting will help you know when your weed is ready to harvest.
Buds crackle when smoked
This is the presence of residual fertilizers in your buds. This can be avoided by flushing your plants two weeks before harvesting, but at this stage, it’s too late and should be notched up as a learning for future marijuana grows.
Most growers come across marijuana plant problems during a grow, knowing how and when to deal with them is the key to ensuring your grow is wasted. The above marijuana trouble shooting guide should help point you in the right direction.