How To Fix Overwatered and Underwatered Cannabis Plants
There is a balancing act to how much water a Cannabis plant uses, and if it is absorbed by the roots, or through the foliage via transpiration. For a beginner grower, attempting to find the balance can result in either over-saturating your growing medium or under watering the plants. In this article, we explain how to diagnose the problem, the ways to restore, and our top tips.
1. Overwatering Cannabis Plants
There are many valid reasons why a Cannabis plant that is being grown indoors or outdoors, can become overwatered. The main one is down to inexperience combined with the illusion that the more water and nutrient solution is given, the faster the plants will grow.
Reasons for overwatering
• A poor-draining growing medium.
• An overzealous beginner grower.
• The pot size is too small.
• The growing medium is cold.
• Feeding when lights are off.
What Are The Signs Of Overwatering?
A Cannabis plant may not show signs immediately that it is unhappy and has become oversaturated. The leaves will begin to droop in a downwards fashion as if they have chosen not to photosynthesis as once before.
Due to the excess amount of water in the growing medium, the plants will struggle to offload the water through transpiration. This will completely disrupt the growth, nutrient uptake, and cause a grower to abandon their vapor pressure deficit chart. Depending on how thick and dense the growing medium is, can also determine how little the amount of dissolved oxygen present will be.
How To Restore
The easiest thing to do is simply to allow the growing medium to completely dry out, before considering watering again. By giving your plants 2-3 days to dry out and fill the roots with oxygen and fresh air, the roots will be encouraged to search out for new air pockets.
The dry conditions will also prevent bad bacteria thriving and limit the development of pathogens that depend on high moisture and low-oxygen environments.
What To Remember
• Allow your pots to completely dry out until they are very lightweight.
• Check on the growth structure and vigor of the plants as they begin to respond.
• Pathogens prefer low oxygen and wet conditions to live.
1. It is better to feed smaller amounts of water or nutrient solution, on a more frequent basis. Younger plants prefer this method as it encourages maximum root growth potential and allows Cannabis plants to break down the food easier.
2. Avoid feeding late at night close to lights out, and especially when plants are asleep during the darkness period. It is best to water them after the first hour when lights have turned on.
3. Using a pump and dripper lines connected to a plug timer will be your best bet at timing the watering times every day, without compromising the routine. An excellent way of reducing the physical work involved when watering.
4. The best way to judge how happy your plants are is to access them by appearance. Ideally, the fan leaves should be angled at 45 degrees facing towards the sky. When the leaves begin to droop this is a sign of over or underwatering.
5. Be vigilant of foul-smelling odors developing inside the grow room. When using organic growing mediums and liquid feeds, it is very easy for the lowest parts of the pots to become a breeding ground for unwanted bacteria.
2. Underwatering Cannabis Plants
There can be several reasons where a Cannabis plant is neglected and underwater. Sometimes it may not be practical to water your plants every day at the same time. However, once a growing medium has become totally dry, depending on how dry the air is it can lead to the plants becoming stressed, tired, and deficient of nutrients.
What Are The Signs Of Underwatering?
The plants will look lifeless and close to death, with their fan leaves facing down. The root hairs will also begin to dry out, become thin and crisp at the tips, and the way the plants transpire will be severely affected.
The leaves will become dry, crispy, and depleted, and the foliage will lose its shine and soft, waxy characteristic. The aroma of the plants will become reduced and begin to smell like dried fan leaves.
How To Restore
The key thing is not to overwater your plants but to feed them enough until you see the liquid run off at the base of your pots. It should take 30-60 seconds before there is a slow rate of water or nutrient solution forming at the bottoms.
Keep the nutrient solution the same as before and do not attempt to increase the E.C level to try and make up for the lost time.
What To Remember
• You should aim to saturate the growing medium until the signs of runoff.
• The growing medium that is being used will have an effect on how much water is retained and how much is drained away.
• Keep the temperature of your water around 15-22 degrees Celsius and avoid cold water.
1. Any foliage that has become lifeless and crisp it should be removed from the plant. Dead leaves will attract insects and unwanted guests.
2. After you have watered your growing medium correctly, wait until the containers are light enough to pick up before watering again.
3. Outdoor growers who may not always be able to water their plants on time can benefit from using a pump and drip lines.
4. Foliar feeding Cannabis plants is an excellent way to revitalize them, as well as saturating the growing medium. This will help restore the amount of moisture they can transpire.
5. Cannabis plants grown in smaller pots will always dry out quicker, so it is a good idea to plant into a larger pot that can hold much more moisture.
There is a balancing act to how much water a Cannabis plant uses, and if it is absorbed by the roots, or through the foliage via transpiration. For a beginner g
signs of underwatering cannabis
Consistency in watering routines supports another vital building block of cannabis—nutrition. Your plant’s root system will absorb essential nutrients from its growing medium, but only when pH levels are optimal (6.0–7.0 pH for soil, 5.5–6.5 for hydro/soilless/coco). The key is to keep plants watered on a schedule. Not only does it keep plants routinely hydrated, but it will prevent fluctuations in pH—a symptom diagnosed by brown spots on middle or lower leaves.
Published : Aug 18, 2019
Categories : Cannabis cultivation
Water your plant until you notice runoff for 60 seconds afterwards. Now, use the same advice as above; wait until the topsoil has dried slightly to avoid swinging to the other end of the spectrum and providing too much water.
To maximise nutrient uptake, aim for 10–20% runoff every time you water. Adopting this approach at an early stage should keep pH fluctuations to a minimum. However, it is especially vital if you are increasing nutrient concentrations for any reason (bloom boosters during flowering, for example).
It’s possible to get your plant back on track after a period of underwatering, depending on the severity of the situation. If your plant has been significantly neglected and is literally lying on the topsoil, then the chances are low. However, if all you’re seeing is slight drooping of the leaves and general wilting, all it takes is readjusting your watering schedule.
The success of a cannabis grow depends on how well the cultivator manages to balance all of the factors required for plant health. Too little nutrients can lead to deficiencies, whereas too much can lead to root burn. A lack of light will result in stunted growth, but if the light source is too close, leaves will wilt and burn. If the humidity is too high, mould is likely to form, and if it’s too low, you’ll end up with dry and unhappy plants. The exact same can be said for watering.
Even if you know how to manage water-related issues, you still need to establish the best time to water cannabis plants. Timing goes hand in hand with the techniques listed above, varying according to the seedling, vegetative, and flowering stages.
Pot size is also an important factor to consider here. You’ll need to start your seedling off in a small pot and gradually transplant it into bigger pots as it continues to grow in size. If you place a small plant into a big pot too early, the roots won’t be capable of taking in a lot of water from the soil, which means the medium will stay saturated for too long.
Watering in the evening is an option, but the lower evening and nighttime temperatures can lead to a buildup of mould.
Underwatering and overwatering produce similar symptoms and are both detrimental to plants. Learn how to manage watering correctly to avoid these issues.
3. Another symptom of overwatering a cannabis plant is yellowing of the leaves. This is a sign of a nutrient problem, that is a side-effect of overwatering.
1. One primary symptom of overwatering is drooping leaves. However, it is not the same kind of droop you see when underwatered – where leaves look wilted. It is the opposite in fact. Leaves are so full of water, that they are being forced to curl in on themselves. It results in them becoming very firm.
Overwatering and under watering your cannabis plants can cause multiple symptoms and may even slow down growth. It’s all about understanding your plants and finding a sweet spot. We explore how to recognize and fix these issues, as well as take a look at the importance of water quality in general.
2. Additionally, the rate of growth of overwatered plants will slow down dramatically or may even come to almost a complete halt. This is due to the anaerobic conditions that arise due to the lack of oxygen accessible to the root system.
PPM is another important factor when it comes to water quality. Ppm, or parts per million, is a method of measuring the amount of minerals that have dissolved into the water source being used. So, a reading of 90ppm will indicate that there are 90 milligrams per litre of minerals present within the water source.
2. Underwatering occurs when growers simply aren’t meeting their plant’s demands. Without adequate water, the root system will dry up and growth and yield may be reduced. Be sure to water your plant when the top inch of soil has dried out. Leaving it any longer than this may start to have detrimental effects.
This question actually has many different answers, as many different variables are at play. For this reason, there is no exact answer. For example, temperature, humidity, and other environmental factors can all change how often water will be required.
Monitoring ppm is quite advanced, and while useful, is not essential for novices finding their feet. Just bear it in mind as you look to expand your knowledge and skill.
Being aware of the PPM within water allows growers to avoid giving their plants too many or too little minerals. A lack of minerals may lead to deficiencies, whereas too many may cause burning to occur. Cannabis plants prefer a ppm of around 500 when in the vegetative phase, and favour a ppm of around 1000 during the flowering stage of the grow cycle.
We explore how to recognise and fix cannabis over and underwatering, as well as the importance of good quality water.
Consistency in watering routines supports another vital building block of cannabis—nutrition. Your plant's root system will absorb essential nutrients