This is the easiest way to tell if your plant is experiencing heat stress and all you have to do to fix it is lower the temp to the appropriate levels.
Nutrient burn is another common issue beginners and even expert growers often face, as they tend to get overzealous with feeding their plants. When it comes to nutrients, less is always more!
Nutrient burn is essentially what happens to your plants when you’ve been feeding them too strong of a nutrient mix, and/or too frequently. The edges of your leaves will begin to brown and look crispy like they were burned, and growth will slow down drastically.
Another issue caused by high humidity and low airflow is bud rot. Overwatering can also cause this to happen, and essentially the results are the rotting of your cannabis buds. It will start from the inside and will slowly turn them brown and moldy until the whole bud is ruined.
If not taken care of, you will see webs that look similar to spider webs, and they will be covering your leaves and plants. Usually at this point it is too late, but if you do catch them early on you have some options.
If you notice these signs on your plants, all you’ll need to do is water them more frequently and give them more per watering. If your leaves are drooping, give them a quick watering and within 30 minutes they will be standing right back up nice and perky!
While not as common as the previous issues, this pest is definitely one of the most damaging and difficult to deal with. If you don’t catch these guys early on, there is a good chance you won’t be able to get rid of them. That is why it is so important to always monitor your plants and to comb through them every couple of days so you can spot pests and other issues as early on as possible.
Also, most people recommend spraying a neem oil mix onto your plants to eliminate these bugs, but I am not a big fan of that. Reason being, if you are in flower, you don’t want to be spraying your buds with anything as it can lead to mold and rot. The other reason is the spray leaves a lasting foreign smell on the plants that is unpleasant and something I don’t want in their system.
Similar to spider mites, aphids hang out on the undersides of the fan leaves, but they are green and have long legs almost like a grasshopper. They are pretty tiny as well so I also recommend using the trichome scope for looking at aphids on your leaves. You will see them crawling around and what aphids do is suck the nutrients and water out of your fan leaves, which causes them to wilt and die.
The amount of light you give your plants is strongly correlated with fast your plants grow, as well as how much buds your plants will produce during the flowering stage.
What to do: Use the checklists below to diagnose whether your plant is over-watered, under-watered, or has a root problem.
A good growing environment is crucial to the health of your plants. When the temperature (and to a lesser extent the humidity) is too high or too low, your plants will not grow properly no matter what else you do. Plants seem unhealthy and buds just don’t fatten up. You may also end up with problems related to plant stress such as hermies.
Once you’re positive you’re watering correctly, providing the nutrients your cannabis needs, and you’ve adjusted the water pH to the proper levels, nutrients problems should start clearing up quickly. Remember, if leaves get damaged from a nutrient problem, it is unlikely that particular leaf will ever recover and turn green. What you’re looking for is that the problem stops spreading, and that any new growth appears green and healthy.
Because your plants need CO2 when the lights are on in order to function properly, a completely sealed off grow box is not good unless you’re artificially adding CO2. Your plants will suffer if they don’t get enough CO2 in a sealed grow box even if the temps are completely under control.
This rule is referring to how many watts of electricity are actually being pulled out of the wall, not some sort of “equivalent” amount of watts. If an LED pulls 90W of electricity from the wall, you should plug that into the equation, not the claim that it’s “equivalent” to a 400W HPS light. Same for CFLs, if you have a CFL bulb that pulls 26W of electricity from the wall, you should count that as 26W, and ignore the fact that it says “equivalent to 100W” on the front.
Step 1: Verify Watering Habits & Root Health
If plants are growing very slowly, if they’re not drinking much water, or otherwise aren’t doing well without showing any other major signs of problems, often the problem is the plant simply needs more light to thrive.
Many new growers don’t realize they’re not giving their plants enough light. As a very general rule, you want at least 100W worth of electricity going into your indoor grow light to harvest a few ounces. More is often better.