Nov 24, 2020

How to Identify Plant Deficiencies

Plant deficiencies. We all get them, but what exactly do they mean? Every grower runs into signs of plant deficiencies during their growing career. The important thing is that you know how to spot them and can troubleshoot them quickly and effectively.  

When examining your plants, you might see yellowing leaves, brown spots, and sometimes even leaf-curl. Watering, pest problems, temperature control, and nutrient burn can all cause plant deficiencies and affect plant growth. 

There are many different deficiency symptoms, so we are going to touch on some of the most common ones. Checking the state of your plant leaves is the most important part of gardening. It is ideal to check leaves every day for color health, spotting, curling, or brown edges.


Yellowing leaves is one of the most common plant issues a grower may face. It happens to everyone, so don’t worry if it’s happening to you. There are a few reasons that you may have yellow leaves. The main cause usually lies within your watering schedule and can be fixed pretty easily.

Over-watering and under-watering are the biggest culprits in your watering schedule. If you notice yellowing leaves on your plants, check the soil first. Dig a hole with your finger and if the dirt is extremely dry then you need to water. 

If the potting soil is extra soggy when you stick your finger in the soil, you have been over-watering. One easy fix for this is to transplant them into new, dry soil and let them dry out completely before watering again. This quick-fix usually nips it right in the bud.

If your soil feels good—not too dry, not too wet—then it is not your watering schedule. It could be an issue with the plant’s nutrient uptake. All plants need three primary macronutrients- nitrogen, phosphorus, and potassium. When one of these is missing or deficient, your plant will start to show signs. 

Yellowing leaves are a major sign of nitrogen deficiency. If you suspect nitrogen deficiency in your garden, you can add some fertilizer to give your plants an extra boost. 

Try adding Feather Meal or Bone Meal, as these two supplements are very high in nitrogen. They are both slow-release, organic fertilizers, so they should not burn your plants when adding them to your medium. Always check the label or talk with your local grow expert and make sure to give your plant the appropriate amount.


Another common sign of plant deficiency is browning leaves or leaf tips. More than likely, it is because of nutrient lockout. Nutrient lockout is due to a PH imbalance in your reservoir. Make sure to always check the PH of your medium and be sure it is set appropriately to match your nutrient regimen.

If your PH level is correct, then it could be from a watering issue again. If the leaves are soggy and brown, that is a clear sign you have over-watered. If the leaves are brown and dry and drop prematurely, then your plants just need thorough watering. 

Most of the time, you will notice browning or yellowing on the lower leaves, so you have time to fix this problem. Just keep a close eye on it and make sure it does not spread up to all of the leaves. If you check your plants every day, it will help you catch deficiencies with plenty of time to correct them. Build this habit early to develop a nice, green thumb!


The final, most common sign of plant deficiency is plant leaves curling. There are a few reasons your leaves are curling. This is a self-defense mechanism, and the main cause is underwatering. 

When your plants don’t have enough water, they attempt to conserve the water within their roots. They begin to slightly curl to prevent future water loss. But if you’re certain it’s not from underwatering, then it could be from something entirely different. 

You could be dealing with a viral infection or a pest issue. If this is the case, early detection is crucial. This is another reason to check your plants every single day.


Whiteflies can be the culprit with pests, especially with house plants. Fruits and flowers will not develop on your plant with a white fly infestation. The growth of the plant will be stunted and if not taken care of, whiteflies can kill it altogether. 

There are a variety of different, natural ways that you can rid your plants of these pests. A mix of dish soap and water is the oldest trick in the book, but sometimes that just is not enough. A great organic product called Lost Coast Plant Therapy is another great option. It is safe to use on your plants up until the last day of harvest. 

In addition to white flies, it is important to check your plants for signs of mitespowdery mildew, thrips, gnats, and aphids.


If you are not dealing with pests and your water schedule is on point, then you may be over-fertilizing. Be careful when using a heavy feeding schedule, as you can over-feed your plants, causing them to turn brown, curl and burn up.

If you start to notice your plants burning, cut your feeding schedule back. You can always start with a lighter feeding and work your way up, but you cannot take it back if you give them too much food. Again, make sure to always adjust the PH with your nutrient line. You will want to stick to 6.0 for soil or coco and about 5.6-5.8 for hydroponics.

Once all these things are taken care of and you’re still dealing with leaf curl, then you’ll want to check the temperature of the room. This is especially important when dealing with a greenhouse. 

If your greenhouse gets too hot, this will cause immediate stress on the plants and they will curl up and die. Do not let this happen! Make sure to always check the weather first and have the appropriate air circulation before moving your plants to a greenhouse.

When growing indoors, it is important to check the distance of your lights to your plants. Make sure that they are not too close or the powerful lights will burn your plant leaves. We recommend keeping your light at least twelve inches above your plants. This can vary by light, so always check manufacturer recommendations.

Believe it or not, leaf curl can also be caused by cold temperatures. If not taken care of, your flowers will end up loose and extra leafy in the end. That is if they even make it to harvest. You can quickly fix this issue by adding a space heater to your indoor grow room. 

Make sure to have a thermometer set up, so you can see what the temperature of the room is set to at all times. For example, you can set the space heater on a timer to heat the room to 80°and it will turn off automatically as it hits that temp.


Troubleshooting plant deficiencies can take time and effort. But if you take these preventative measures, you’ll save a lifetime of trouble in the long run. 

The issues usually arise when you are rushing and not taking the time to check your plant’s leaves, soil, and grow room temperature. If you pay attention closely, it is not too hard to notice and troubleshoot plant deficiencies. Always set aside enough time to check on your plants so you can better recognize these deficiencies and you will have your plants calibrated before you know it!