How Do You Heal Your Dying Cannabis Plant?

Grow problems are a normal part of every grower’s journey. As with any situation in life, the important thing is to stay calm and figure out what you can do to help your cannabis plant recover. There can be many signs that something is wrong, including yellowing or curling leaves, stunted growth, underdeveloped buds, pests, and more. Whatever the issue, there are usually steps you can take to address it before it’s too late.

General Guidelines

• It’s important to catch symptoms early. For example, if you notice that some leaves are starting to change color, there are several quick checks you can make to help identify the possible cause of the discoloration.
• It’s important to monitor how quickly the condition is developing. Has there been a significant change in the plant’s appearance over the past 24–48 hours, or is it something that has gradually progressed over several weeks?
• Using a calendar or growing diary to track changes throughout the growing process can be helpful. For example, note when you added nutrients, how often you water, and when you change the room temperature or humidity. Mark those dates and write down the relevant details.
• Taking preventive measures can help reduce the risk of serious problems and, in some cases, prevent your cannabis plant from dying. For example, routine pest inspections can help prevent infestations from becoming severe and difficult to control.

Diagnoses and Treatment Strategies 

A sickly cannabis plant can show a variety of symptoms. Below, we discuss the most common signs to look out for and the steps you can take to help your stressed or unhealthy-looking plant.

Leaves Are Turning Yellow 

One of the most obvious signs that something is wrong with your cannabis plant is yellowing leaves. There can be several reasons for this, but you should first check the plant’s water and nutrient intake. 

Watering Problems

Overwatering is one of the most common mistakes when growing cannabis. Excess water can weaken the plant, while underwatering can also negatively affect its health. In general, young cannabis plants require less water, while plants in the vegetative stage can take up considerably more.

Symptoms to watch for include yellow or brownish leaves, wilting, crispy or dry leaves, and bone-dry soil.

Perform simple soil checks to see whether your plant is receiving sufficient water. Place your fingertip slightly into the soil to determine whether it feels moist, dry, or bone-dry. This will give you an idea of the moisture level near the surface. Measuring the plant’s weight can also be helpful. Check its weight at different times, such as after watering, one day later, two days later, and so on, to get a better sense of how quickly the growing medium is drying out.

Whether you’re using soil, rockwool, or coco coir can also affect the plant’s water uptake, drainage, and moisture retention. Because of this, it’s also useful to measure pH and E.C. (electrical conductivity), which can be done easily with digital meters. EC levels should be kept within an appropriate range for the growing medium and stage of growth rather than being too low or too high.

When the growing medium is drenched in water, it will usually dry out within 2–3 days. If it takes significantly longer to dry, the issue may be overwatering or poor drainage. If the growing medium dries out too quickly, the plant may not be receiving enough water.

Solutions

Of the two issues, overwatering can be more challenging to address.

1. Start by allowing excess water to drain away as thoroughly as possible.
2. Keep containers slightly elevated off the ground or place them on a suitable drainage surface, such as a rack or tray with adequate drainage. This helps prevent the plant from sitting in pooled water.
3. Once the watering issue has been corrected, check the plant for signs of nutrient deficiency before adding additional nutrients. Excess water can leach some nutrients from the growing medium, but adding nutrients unnecessarily can also cause problems.

With underwatered plants, the solution is straightforward: give the thirsty plant more water.

1. Water the growing medium thoroughly and allow some excess water to drain from the bottom of the container.
2. Repeat the finger test or use the container’s weight to help determine when the plant needs to be watered again.
3. Installing a drip irrigation system can be helpful if you don’t have time to water your plants regularly.
4. If your plants continue to struggle with underwatering, check the containers. If the plants have outgrown their containers and the root system has become restricted, consider transplanting them into larger containers.

Nutrient Problems

Strange discoloration or curling leaves in cannabis can also be attributed to nutrient issues, most notably nitrogen deficiency and nutrient burn (overfeeding). Nitrogen is a crucial macronutrient, the N in the N-P-K formula. Without it, plants won’t be able to conduct photosynthesis, or convert light energy into chemical energy. If you don’t fix the issue, your cannabis plant can eventually die.

Most N-P-K nutrient solutions are readily available, and they include instructions on the package regarding how much should be used. However, one recommendation is to use slightly less than the amount stated on the package. It is also important to know that cannabis plants require a different balance of macronutrients depending on the stage of growth. The optimal feed may further depend on the type of cannabis strain, which is where it might get complicated.

The general rule is that cannabis needs larger amounts of nitrogen during the vegetative phase and higher amounts of phosphorus and potassium during the flowering stage. Nitrogen stimulates leafy green growth, while phosphorus and potassium support flower development.

Nutrient deficiencies can occur even when you follow all instructions correctly. Cannabis plants may suffer from nutrient lockout, which means the growing medium’s pH is either too acidic or too alkaline. This can interfere with nutrient uptake by the roots.

A nutrient issue can also present as nutrient burn, such as when too many nutrients are added to the growing medium, creating a toxic effect on the plant. Uncomposted organic material can also contribute to nutrient problems. Dark-green leaves with yellow or brown tips are indicative of nutrient burn. There could also be reddish or purple stalks and branches, and leaf tips may start to die.

Solutions

1. Whether dealing with a deficiency or lockout, you again need to use a pH pen and test a soil sample. For soil, the correct pH range is generally between 6.0 and 6.5. Values outside this range may indicate a nutrient uptake imbalance.

2. For nutrient deficiency, it’s obvious that you need to boost the feed. Add nutrients gradually and observe how the plant reacts. Grow boosters can help, too.

3. For nutrient burn, you may want to flush the soil with pH-balanced water. Then, give the plant time to use the excess nutrients before adding more feed solution. Here’s a guide on how to flush cannabis plants and the benefits of flushing.

Stunted Growth

Several factors can contribute to stunted growth. Plants can stop growing because of nutrient deficiencies, insufficient light, environmental stress, and other factors.

Nutrient Deficiencies:

1. Use a grow booster solution (many products are available to purchase online).
2. Combine the grow booster with an organic mycorrhizal fungi supplement as a root drench to help optimize nutrient uptake by the plant’s root system.
3. Note that some nutrient deficiencies require a different solution. For example, stunted growth due to calcium deficiency can appear as discolored young shoots and curled new growth. In this case, apply a Cal-Mag plant supplement as instructed on the package.

Lights:

1. Introduce a cycle of 18 hours of light and 6 hours of darkness when plants are in the vegetative stage. Prevent any interruptions to the light cycle.
2. Optimize the lighting if you are growing indoors. Check out these 7 quick tips for lighting. 

Stress:

1. Avoid transplanting the plant multiple times. Transplanting a seedling directly into its final, appropriately sized container can help minimize transplant stress.
2. In general, avoid extremes in the growing environment. Stress can result from temperatures that are too high or too low, excessive humidity, light interruptions, and other environmental factors.

Here’s how to maintain appropriate temperature and humidity ranges during each stage of growth:

Seedlings

• Humidity range: 65-70%. Higher humidity can help reduce water loss from seedlings before their root systems are fully established.
• Temperature: 68-75°F. Reduce the temperature by 5-7 degrees when the lights are off. 

Vegetative Stage

• Start to lower the humidity level by 5% each week. The lowest in the range you can go is 40%. During the vegetative stage, the plant increasingly takes up water through its roots and loses water through its leaves.
• Temperature: 70-80°F. Reduce the temperature by 5-7 degrees when the lights are off. 

Flowering Stage

• Humidity range: 40-50%.
• Temperatures: 67-75°F. 

Before Harvest

• Reduce humidity to the 30-40% range two weeks before harvest.
• Temperatures: 65-74°F. Drop temperatures by 5-10 degrees when the lights are off. 

Stretching

“Stretching” refers to the rapid elongation of cannabis stems. This is a natural part of the vegetative stage and can be influenced by genetics and environmental factors. However, excessive stretching can sometimes cause cannabis plants to become structurally weak, increasing the risk of toppling over.

A quick fix is to reposition the lights if your seedlings are becoming “leggy” or their stems are elongating too much during the vegetative stage. This can happen when plants do not receive enough light and stretch toward the nearest light source.

Excess heat can also contribute to lanky seedlings. So, it’s equally important to stick to the recommended temperature ranges for each growth stage, as outlined above. Fans and air conditioning units can help regulate temperature.

Most cannabis plants experience a “flowering stretch” once they enter the flowering stage. They can gain significant height during this period, which may increase the risk of toppling over if the plant is already leggy. Support structures can help prevent this.

Underdeveloped Buds

Another red flag is when cannabis plants produce poor-quality flowers. Underdeveloped or “popcorn buds” are small, airy, and less dense than well-developed flowers. How can you help them?

1. Defoliate carefully. Buds should not be completely hidden beneath a dense canopy, but excessive defoliation can also stress the plant. The goal is to maintain adequate light exposure and airflow.
2. Don’t forget to provide adequate phosphorus and potassium once the vegetative phase is over. However, avoid increasing nutrients automatically, as plants still require nitrogen and other nutrients during flowering.
3. Practice pest control. Some pests feed on flowers. A pest such as a budworm can damage buds and leave them vulnerable to further problems.

As a side note, perform pest control routinely, as different types of pests may target various parts of your plant and cause significant damage. See tips here on how to deal with five of the most common cannabis pests.

Happy growing and try not to kill your plant!

Read more from Soft Secrets:

• 10 Mistakes To Avoid When Growing Cannabis Indoors
• 9 Cannabis Germination and Seedling Problems and How to Fix Them
• How to Water Cannabis Plants the Right Way

Disclaimer: Cannabis cultivation laws vary by region. Readers are advised to check and comply with the regulations applicable in their local jurisdiction before cultivating cannabis. 

Last updated August 26, 2026