I KNOW YOUMAY LOOK AT THE TITLE to this article and think that you are above making these mistakes. Maybe you are, but in reality, percentage-wise, ego aside, you are likely an offender of these basic fundamentals in cannabis (or any other plant’s) care from time to time. My articles are designed to make you an artist, a druid (an exceptionally highly skilled all-natural grower, in my world); and much like auto racing, it really comes down to a whole shit-load of smaller tweaks/skills. When they all add up, it equals big changes in the quality and size of your final product. So, hey, don’t just write this one off thinking you would never make these mistakes and instead just always “add/fix stuff”—The more ya know—heh heh. Let’s get cracking, shall we?
How Often Should I Water?
You need to understand first off, that asking anyone else a question like “how often should I water” is pointless. Your watering schedule will be whatever it needs to be per your own particular growing environment. Plants growing under 86 deg. F. in 45% humidity are going to need a lot more water than those same plants growing under 80 deg. F. in 60% humidity—it’s all about: METABOLISM. You need to get the truth of this, seriously; okay, let’s continue…
In the photo you can see the very first initial signs that your plant is getting too much water. Notice the downward curl of the lower leaves. Look where I have circled in the photo and you can see a slight discoloration along the edges of some of the mid-level leaves. This is another sign of overwatering along with the leaf curling as shown. One of the very best ways to avoid this problem proactively is to make sure you have plenty of something like perlite or pumice in your soil mix to make sure there is plenty of aeration. If you combine overwatering with low soil aeration you will likely end up with anaerobic microlife in your container. This is very bad—and will stink like a sewer if you pull the plant roots out of the pot.
Nitrogen deficiencies usually come soon after anaerobic microlife come on the scene. That plant in the photo—which I purposely overwatered for the sake of this article—at this point has no permanent damage and can be brought back to full health within a week or 10 days with just good watering habits. One of the best ways I use to tell when my plants need water is to simply lift up the containers and judge their weight. When doing this it is super important you set the containers back down GENTLY so you don’t end up compacting your soil in the container. Now, for larger containers that you cannot lift to check you have a couple of options, first, use a quality moisture meter to check the water levels in your soil. Another way is to have a skilled look at the very bottom leaves of the plants, because one whole day before the plants will droop/go limp from drought stress, the bottom leaves will slightly droop. You need a good eye to see this, just pay attention and you will see what I mean and learn this skill.
Too Much Food is Bad in Any Environment
I think a lot about my container life (plant included, along with microbes, and everything in-between) like I think about my freshwater aquarium. It’s a whole “universe” unto itself. Much like in an aquarium ecosystem where too much food will literally kill all your fish, the basically exact same results will occur in your cannabis growing ecosystem—especially in the containers; for pretty much all the exact same reasons. I overfed this plant with liquid fish fertilizer (5-1-1 Alaska) and dry soluble kelp (Humes) to get the photo, over the course of 2.5 weeks.
In the photo, you can notice how the stem, petioles, and leaf veins, have become purple. Since calcium (Ca) and magnesium (Mg) availability fall off, you also lose potassium (K) and nitrogen (N) right after that—making it hard to “see” what the real cause is, adding more available N and K will just sign your plants’ death warrant. This all happens for a couple of reasons at least. With all the “extra” available food laying around, massive amounts of microlife become active consuming it which usually will drop the pH of the soil downwards to 6.0 and below. Phosphorus (P) deficiencies will follow as well.
Another way this can happen on the flip side of the coin, so to speak, is when extra nutrient salts (from liquid fertilizers high in P and/or K especially) build up around the root zone (rhizosphere) driving the pH upwards in those zones; while at the same time the rest of your soil might have perfect pH. What I mean by “perfect pH” is about 6.9 – 7.4 in almost any all-natural style soil mix garden, in containers. Normally the plants can manipulate the rhizosphere to their will, changing the pH as needed to make different elements more or less available, in concert with the microbial life. The built-up salts drive the pH upwards, making iron, manganese, copper and zinc unavailable, along with hyper-dehydrating the rhizosphere when the soil dries out. Bad news for all the life in the rhizosphere, including roots.
The real keys to not overfeeding are things like keeping your plants happy all the time so you don’t start adding “things” to “fix” stuff, LoL. This is pretty easily done with a good soil mix and good water that contains levels of Mg and Ca; the levels of these in your water will depend upon your soil strength, but a good starting point is about 60 PPM to 80 PPM; and my favorite way to accomplish this is using a pure water source like: rain, distilled, or reverse osmosis (R/O) filtered, and blending in well or spring water (chlorine free and NOT softened) to achieve your desired PPM levels. That’s a HUGE thing right there, so check it out and see for yourselves.
Finally, I just want to let you all know that don’t know already, some genetics tend to get some purple striping up the stems, along with having purple petioles (the little stems that connect the leaves to the larger stems). Cold temperatures can also cause the purple striping of stems, and purple petioles. Very rarely will the leaf veins be purple, genetically, so if you see that, you may indeed have some issues. Even on plants like these you can still watch for signs, because the petioles nearest the tops of the stems should be way less (or not at all) purple, always. Also, stems are very rarely solid purple, genetically, and you can easily tell when these things are happening by noticing these subtle signs occurring. Merry Christmas and Happy Holidays to all my esteemed homeskillets—cheers.