The More You Grow: Overwatering

BY KIM EMERSON ILLUSTRATION BY STICKY

I was standing in the veg room one day, overlooking the plants, and something just didn’t feel right about them. They look and move a certain way when everything is dialed in, and I just couldn’t figure out what was wrong. I was going through checklists and looking at data collected, trying to figure out why the plants looked unhappy.

Suddenly, a recent change we had made came to mind. We had added an extra water cycle to our veg room. I began to research what it looked like when you’re overwatering your plants—a problem I wasn’t quite sure we had, but I couldn’t rule out. Some signs of overwatering are:

• Leaves curl downwards

• Leaf tips turn yellow

• Leaves will fall off for no reason

• Plant leaves droop (hanging down)

• Slow plant growth, stunted

• Constant damp top soil or coco

• May look like a magnesium deficiency

• May seem like a nitrogen deficiency

It clicked suddenly for me: although the plants in my veg room were big and tall, they were stunted in their thickness and strength, the leaves were constantly turned down, and there did appear to be signs of nitrogen deficiency.

I began by timing the amount of water I was giving the plants in each water cycle, so I was able to approximate how much water each plant was being given individually. At first, because we had light buckets daily, I dialed back the number of times watered to once per day, but increased the amount of water given. While hopeful that would be the “quick fix” to my problem, I found that the plants didn’t respond completely to this. Many had become accustomed to the twice daily watering. To combat this problem, I reduced the amount of water given twice a day to those plants that did not respond well to once a day watering, and there was immediate improvement.

This showed me that there are easily many ways to overwater a plant, not only in the amount of water you give while watering, but also in the number of times you give the plant water. There are other factors, of course, but mostly the number of times you water is based on your planting medium (this veg room used coco noir). However, soilbased rooms need to be watered less frequently.

The major reason overwatering can be a problem for plants is that there is oxygen uptake within the root system, and in many mediums there are air pockets created around the root system so that the plants can breathe. Unfortunately, if we overwater our plants, we are essentially drowning them, as we create an environment that becomes the perfect infestation site for many molds and aphids, as well as root rot, which can take down a whole plant from the base.

It is important to make sure that your pot size matches your plant regardless of the plant medium you use. The water is pulled from the soil through the root system, and if the root system isn’t able to reach the majority of the plant or quickly grow into its new pot size, it will not be able to reach and uptake the water like one would hope. Another helpful hint is making sure you have 1020% runoff while watering, which helps to flush the old nutrients from the soil.

In broad brush strokes, you should be watering your soil base every two to three days, with coco mixes being watered every one to two days. You can measure how your plants are doing on water absorption via a number of different methods, but there are two tried and true options. The first method involves putting your knuckle into the plant pot and, if it is wet, your plant still needs time to dry out. Another effective procedure is the lift method: If your plant pots are heavy, you are properly saturated, while if your plant pots are light, you will need to water.

My favorite thing about cannabis plants is that they are very responsive.

If you don’t start to see improvement quickly, you may want to check through more environmental problems that could be reducing the water intake of your plants, such as weak grow lights, small plant/big pot, heat above 85° F/30°C) and cold below 70°F, and a humidity that is too high. A number of things go into keeping the cannabis plant happy, so if you have a careful eye and a curious mind, no problem is too big or too small.

overwatering

ILLUSTRATION BY STICKY