Powdery mildew is a fungal infection on plant leaves caused by high humidity and poor ventilation. Preventing powdery mildew is as simple as keeping your growroom’s humidity level below 65% and providing ample air circulation. Air circulation can be improved by venting your room more often. Including ceiling fans or oscillating fans in your room can make a big difference.
Spraying your leaves with the lights out can invite powdery mildew onto your plants. There are a couple ways to treat powdery mildew. Spraying or dusting your plants with sulphur will kill the powdery mildew.
Neem oil and pine tree oil foliar sprays also work at removing and preventing powdery mildew. For large-scale removal, the best choice is a sulphur burner. This will vaporize sulphur pellets, filling your room with a sulphur mist, killing the powdery mildew.
There are numerous reasons why your leaves may be yellowing. The most common problem is a yellowing of the older, lower leaves on the plant. This is caused by a nitrogen deficiency. There is not enough nitrogen available for your fast-growing plants, causing them to take nitrogen from the older leaves and send it to the new shoots. This can usually be corrected by adding some more nitrogen to your feeding schedule.
Adding worm castings and pine tree oil are two safe ways to get more nitrogen to your plants. If the yellowing is occurring in the newer leaves, it is likely caused by a micronutrient lockout. The usual cause of this is a toxicity of either phosphorus or potassium, or high or low pH levels.
Flush your growing medium with pH-balanced water and begin watering with a quality nutrient solution. Heat from your lamps can also cause some of the leaves closest to the bulb to turn yellow or even dark brown.
Simply position your bulbs further from the canopy. Finally, overwatering can turn leaves yellow. The lack of oxygen available in the root zone will starve the plant and affect chlorophyll production.
Spider mites are the bane of every indoor gardener’s existence. These miniscule insects feed on your plant’s juices and can decimate crops. Spider mites are hard to detect, mainly because they are so small, and once you realize you have them, it is often too late.
You may notice stunted growth initially, then on closer inspection, there may be some webbing in your plants. The damage will show up as dried-out silvery spots on the younger, more vulnerable leaves, which will die and drop. Affected plants can be treated in a variety of ways.
Many people resort to insecticides. You can also spray plants with neem oil or homemade insecticidal soap (water, dish soap, garlic and cayenne pepper). These two remedies will coat the body of the spider mite, preventing molting and reproduction. Make sure you spray the undersides of the leaves, as this is where many adults and eggs are hiding. Another solution is predatory insects.
Predator mites and ladybugs make great natural spider mite controls, but do not use beneficial insects along with any pesticides or sprays because they will kill the good bugs as well as the bad ones. The best way to deal with spider mites is to prevent them from getting into your indoor garden in the first place. Always be clean and wash up before entering your growroom.
Avoid touching your plants to prevent bug transfer, and keep pets away from your plants. Keeping your growroom temperature below 75°F will also help keep spider mite populations down, as the higher the room temperature, the faster the spider mites can reproduce.
If your leaves are curling up it may be a sign that your plants are trying to reduce their surface area in an attempt to retain water. Two possible problems may be either your lights are too close and are frying your tender plants or your fan may be blowing to strongly and drying out your plants. Try moving your lights a little further away and redirecting your fan so its not blowing directly at your plants.
If your leaves are curling down it may be a sign that your nutrient solution is too strong.
If your plant is lit with a top light this may be an indication that not enough light is reaching the lower levels of your plant. This is quite normal and you shouldn’t be alarmed as the top leaves should capture enough light for your plant to continue to thrive. If you’d like you can provide supplemental light from the side to ensure your bottom leaves are getting enough light as well.