Nothing is more frustrating than having a plant that isn’t growing properly. There are dozens of issues that could be the cause, and it can be tricky to narrow it down. In this article, we’ll look at some of the top reasons why your indoor plants aren’t growing. We’ll look at some of the biggest issues you might face, how to identify it as the cause, and what you can do to correct it.
Too Little or Too Much Sunlight
As you probably already know, sunlight is a major component of plant growth. That sunlight needs can go both ways; just as it’s possible to have too little sunlight, it’s also possible to have too much.
How much light your plant needs comes down to the specific plant you’re growing. That’s why it’s so important to understand your plant; otherwise it would be impossible to provide it with proper care. A tomato plant, for example, is going to need much more sunlight than a peace lily. Giving them the same amount of light is going to be detrimental to one of them.
Signs of Sunlight Issues
Depending on whether you have too much or are lacking sunlight the signs can differ. For too much light, look at the edges of the leaves. These will often start to brown and look burnt out. This is often the first sign that the plant is getting too much light.
For too little, look out for little or weak growth. You might also notice the plant begins to lean in the direction of the light. This is them “reaching” for light as they’re not getting enough. This can lead to weak growth and plants that are unable to support themselves, along with the damage that lack of light will cause long term.
If you’re running into lighting issues here’s a couple of solutions to try:
- First, determine whether you’re getting too much or too little light. You don’t want to exacerbate the problem by going in the wrong direction.
- For too much light, try moving the plant to a new location or place it a few feet further away from the window.
- You can also add thin curtains that will dilute the intensity of the light.
- With too little light, you’ll want to find a location that gets more than the current one.
- Look for southerly facing windows as these tend to get the most sunlight.
- You can also reverse the lack of sunlight tips: move your plants closer to the window and remove any sort of filter that might dilute the light.
- If all else fails, you can also supplement with grow lights to increase light exposure.
- Be aware that sunlight intensity tends to drop in winter, so it may require some work to balance.
Wrong Amounts of Water
Watering is one of the easiest things to get wrong when caring for indoor plants. Unlike outdoors, we are the sole provider of your plant’s water. It also differs in that container bound plants don’t have any good place to drain excess water to. This can lead to pooling water in your plant’s soil, which can lead to serious issues like root rot.
Signs Of Water Issues
Like sunlight, water can also be an issue if you’re getting both too little or too much. Too little water will often be readily apparent in the form of dried out stems and leaf tips. Plants will tend to be crunchy, and have an overall dried out feel to them.
Overwatered plants are often harder to diagnose until larger issues present themselves. If a plant seems to be dying, but showing no outward signs of stress, too much water may be the issue. In these cases, check the roots. Overwatered roots will be a dark brownish-black, and will feel mushy. You may also notice discoloration on the leaves of the plant.
A word of caution though, many signs of watering issues can also be related to sunlight or humidity. Browning leaf tips may be due to lack of water, but also can be caused by too much sunlight. When applying a solution, make sure you’ve correctly identified the root cause first.
With watering issues, here’s a few things you can try.
- If your plant is not getting enough water then the solution is simply to water more. Luckily, underwatering is usually pretty easy to fix and shouldn’t lead to long term issues.
- Don’t go overboard though as you’ll risk overwatering. Try watering an extra 1-3” per week and check the issues resolve themselves.
- Overwatering can be a bit more difficult to correct, and can even be impossible if left for too long.
- First, stop watering and hold off until the soil is completely dry. Then, only water until you see water begin to leak out of drainage holes.
- You can also take steps to increase drainage by adding small pebbles at the bottom of your container, or adding extra drainage holes.
- For advanced root rot, you can try using a fungicide to help cure it along with removing any dead roots. This will typically only work for milder cases though, for advanced root rot it’s best to start over as the plant will be unsalvageable.
Wrong Type Of Soil
While not as prominent as the other issues, improper soil can lead to a variety of issues. This is especially true for container bound plants as they have no way to recycle their soil, and also require extra drainage.
This extra drainage requirement is why container gardens should always use potting soil and never garden soil. Potting soil is naturally lighter and allows better drainage. This makes it ideal for container bound plants that don’t have the ground to drain excess water to.
You can test this yourself by picking up a bag of potting soil and a bag of garden soil. The garden soil will feel a lot lighter, and will have a general looser feel to it.
Certain plants also need special soil that is even more well draining than potting soil. Cacti and succulents are one good example that need especially coarse soil to thrive.
Signs of Improper Soil
Improper soil can have many signs, so it can be difficult to tell if it’s the issue. You should rule out other, more common issues before tackling the soil.
In general, it will lead to an overall unhealthiness, lack of growth, and dying plant parts. Many of the signs will be similar to overwatering as poor soil will often be accompanied by poor drainage.
- First, always start out with high quality soil. You never want to use garden soil in your containers as they won’t drain properly.
- You should also look to use specific soil where needed. As noted above, plants like cacti need specific soil that provides extra drainage.
- Lastly, look to repot your plant with fresh soil every couple of years. Soil will naturally compact over time, and this will affect its ability to drain water. Fresh soil will provide renewed drainage and give your plant a healthy medium to grow in.
Fertilizer is another important part of indoor gardening as it allows you to replenish the nutrients in your plant’s soil. Unlike in the great outdoors, indoor soil has no way to replenish expended nutrients. Overtime, this means your plants will run out of nutrients unless you intervene.
Adding fertilizers is the best way to do this, but it’s not without its faults. First off, it’s possible to over fertilize. With many harsh chemicals present in most commercial fertilizer, it’s possible to harm your plants with too much of it. That’s why it’s important to follow the instructions and never over fertilize, especially with container grown plants.
You should also be aware of the differences in fertilizers. We won’t get into here, but the numbers on fertilizer denote the different chemicals in the mixture. Certain plants will need different makeups of these chemicals, so it’s important to match the fertilizer to the plant.
One last note, many plants will go dormant during the winter and not need to be fertilized. If you’re in the dead of winter and experience growth issues, lack of fertilizer is probably not the issue.
Signs Of Lack Of Nutrients
This is another tricky one to diagnose, and it’s usually best to rule out other causes first. Lack of nutrients will present differently in different plants, but will usually be a lack of clear growth. You might notice slow or no growth at all, and a weak looking plant. A lack of nutrients will also prevent flowing and edible plants might not produce any harvestable crops.
If you’ve determined that lack of nutrients is your plant’s issue here are a few things that can help.
- Start by adding nutrients to the soil with high quality fertilizer. As noted above, you don’t want to go overboard as this can shock the plants.
- Water soluble fertilizers diluted to half strength is a good rule of thumb for indoor plants.
- You can also use slow release fertilizers that will provide a contrast stream of nutrients through their lifecycle.
Another issue you might experience is transplant shock. This happens when you move your plant to a new home and the stress negatively affects the plant. Being uprooted and moved is stressful, and your plants might be negatively affected by this.
Luckily, this is usually a temporary issue that will resolve itself. That is assuming you’re providing proper care of course.
When Does Transplant Shock Occur
As noted, transplant shock will occur when you’re transplanting your plant or attempting to grow a new one from a cutting. This narrows this issue down as it should only be occurring during a specific timeframe. If you haven’t recently transplanted your plant then this isn’t the issue.
Luckily, the solution here is time as most healthy plants will recover. Here are a few things you can do to help speed that process along.
- Do most of your transplanting in the spring or early summer. This is when your plants are at their strongest which means they’ll be better able to handle the stress of a transplant.
- Make sure to transplant only healthy plants, doing so with sick or dying plants will likely not end well.
- Follow best practices when transplanting by keeping the soil moist and providing enough sun for your plant.
Too Hot/Cold or incorrect Humidity
While most plants are perfectly happy with typical indoor temperatures/humidity there are still a handful of things to watch out for. First off, be on the lookout for certain plants that have more specific needs when it comes down to temperature and humidity. These are usually tropical plants that only grow in very specific climates.
The other key thing to watch out for is drastic changes in temperature. These are usually brought on by being too close to things like heating vents or air conditioners. While the majority of your home is probably okay, being too close to these can stress your plant.
Generally, temperature or humidity issues will cause mild symptoms, unless the source is very extreme like experiencing freezing temperatures outdoors. These will generally be apparent on the edges of the plant leaves first, and slowly spread to the rest of the plant. Check for any drafts or excess heat that may cause the issue.
Humidity is similar, and will often be the most problematic in the winter. This is when the air is at its driest, especially when running heating implements like a furnace.
If you’re having issues with temperature or humidity here’s a few things you can try.
- Start by moving the plant away from any areas that experience temperature changes. This is often the only fix needed.
- Keep in mind your plant’s needs and if it has any special considerations for temperature or humidity. These are usually more exotic plants that grow in specific environments like orchids.
- Humidity is easy to boost if needed. The quickest way is to simply mist the plants, but there are other low effort methods as well.
Pests Or Plant Diseases
Like it or not, pests and diseases are something that every gardener has to face. These issues can crop up at any time, and can quickly decimate a garden if left unchecked.
Luckily, indoor plants are much less likely to run into these sorts of issues than outdoor plants. That’s not to say it can’t happen, but the other issues are more likely to be the culprit.
Plant Pests/Disease Symptoms
The easiest way to determine if this is the issue for your plant is a visual inspection. Seeing pests themselves is always a dead give away, but there are more subtle signs as well. We have a whole article on common garden pests, and it’s a good primer on some pests you might find. It also goes over ways to identify them without actually seeing them. Many pests will leave clues you can pick up on.
For diseases, look out for unusual signs like spots on your leaves or dying parts of the plant. It can be difficult to diagnose, but most plant diseases will be more likely to affect plants that already have an existing issue.
If you’re dealing with pests or disease here are some things you can try to save your plants.
- Start by ensuring that your plant has no other issues. Weak plants are prime targets for both pests and diseases.
- Learn about the pests you’re dealing with. Different pests will have different methods of control.
- The same goes for diseases. Depending on what is afflicting your plant you may have to switch up treatment.
Lack of Air Circulation
Lastly, we come to an uncommon issue: air circulation. This is often not an issue for most gardens, but I feel it’s important to address nonetheless.
Air circulation issues are most likely to occur for people with larger grows or those growing in seldom visited areas of the home. For example, a large basement grow likely needs some fans to help with proper circulation.
Air Circulation Symptoms
As noted above, air circulation issues are only likely to occur in very stuffy or cramped areas. If you’re not growing in a closet or similar area then this probably isn’t the issue.
If it is, you might notice dust or other buildup brought on by lack of airflow. You might also notice mildew or mold that thrives in warm, stagnant environments.
Airflow is very easy to deal with, here are a couple of options.
- If possible, move the plant to a more open area that gets proper airflow. You can also do things like open doors or windows to help promote airflow.
- If not possible, you can also add a fan to grow location to get that air moving. Even a small fan will make a big difference.
Reasons Why Your Indoor Plants Aren’t Growing
There are a lot of potential reasons your plants aren’t growing, but the above are perhaps the most common. If you’re having plant problems, then start working through the list above to find your culprit. In many cases saving a plant is a simple manner of correcting care. Most plants are quite hardy, so a bit of improper care won’t be the end of them.