Indeed ponds and aquatic plants are the core players behind the naturalistic aesthetic view of your garden pond. As it adds beauty, it also brings some challenges. It’s tough to track nature’s demand and supply. You might see many of your plants dying without giving much time.

The main reasons for the death of pond plants are pH level, high levels of algae, low levels of Dissolved Oxygen, depth of water, overuse of chemicals, and insufficient sunlight.

Watching your pond plants dying is a sad ordeal, and that’s why in this writing, I will explain the reasons so that you may understand and learn why your pond plants die and what to do.

Why Are My Pond Plants Dying: What kills plants in ponds?

There is nothing more sad for a pond owner to see their beloved plants die in front of them. It’s not just about money and effort, they are like our friends and we grow attached to them. So, it’s really not easy to see such an ill fate.

Why Are My Pond Plants Dying

But if you know the causes of pond plant deaths, maybe you can do something to help them. That’s why I’ll discuss some common reasons for plant deaths in a pond. Check out below. I also provided solutions to the problems:

1. Insufficient Sunlight

Undoubtedly sunlight is one of the most important elements for the growth and death of your pond plants. Some pond plants require more exposure to sunlight.

Without sunlight, the photosynthesis of a plant will not happen and it will die slowly. Too many plants in small places also create problems due to the overlapping of one plant upon another. This leads some plants from getting enough sunlight and their leaves to start to become yellow until they die.


When yellow leaves are forming slowly the plant won’t be able to produce flowers anymore. Even plants that have multi-colored leaves may turn green. So try to keep a balance.

To make your task easy, I am giving here some examples of aquatic plants that need sunlight. And these are Water Lily, Water Hyacinth, Lotus, Pitcher Plant, Sensitive Plant, Azolla, etc.

If your pond’s placement is naturally shady, you need to buy those plants which require less amount of sun. Because it’s not practical to move your pond from one place to another.

2. Excessive Sunlight

Aquatic plants that need a small amount of sun exposure during the day won’t be able to grow if they face too much sun regularly.

Excessive sunlight forces these aquatic plants to produce a chemical called Zeaxanthin which ultimately blocks the chlorophyll to produce any oxygen. Also, it gets burned due to release of the excessive heat and thus leaving burn marks on the leaves of the plant.

Too much exposure to the sun means too many UV rays from the sun which is very harmful to this type of pond plant. The sunburn of the plant will also leave a bleached color. And you may also notice a ridgy texture on the leaves and they will turn yellow. If you see any of the symptoms in your pond plant then immediately transfer them into a shady place.

Pond Plants that need shade are Water Hawthorn, Water Snowflake, Water Lettuce, Water Celery, Water Clover, etc. So now simply place them into a shady place of your pond.

After putting them into the shade zone if they don’t survive then it may become too late. You have to get new plants and treat them with your newly gathered information.

Pond Shades

3. The lower level of Dissolved Oxygen

In your garden pond, a large number of the plants are usually submerged in water. And they need a very good proportion of oxygen to survive. A lower level of dissolved oxygen levels will put your exotic pond plant’s life at risk. The moment the level of dissolved oxygen gets below 5 mg/L all types of animals and plants will find it hard to survive.

I won’t recommend you to buy a dissolved oxygen meter because its price is too high. Let me try to help you regarding this issue in the following section.

Just remember these symptoms and signs. If you feel that you might forget that it’s better to write these in your notebook. So here they are:

  • The very first sign is that you will notice that most of the fishes are spending time at the surface water for breathing. They are doing it because there is a lower level of oxygen in the bottom part of water.
  • You may also notice that the fish are eating very slowly and moving towards no eating point. One of the major indications of the absence of oxygen in the pond water.
  • Fish will become fully restless. Too much movement of your pond fish gives a red light of the oxygen level.
  • A strong odor might have a smell like rotten egg or natural lake smell. It can happen due to the excessive amount of fish waste. If anything like this occurs means your pond has insufficient oxygen.
  • A thick layer of algae on the surface of the water is also an indication of a low level of oxygen.
  • An extreme climate may be another reason for the low level of oxygen in your pond. After heavy rainfall or high-speed wind, your oxygen may become low.
  • The color of your pond water might turn into a brownish or blackish color. It’s another way to detect a lower level of oxygen manually.

Now after finding the problem of oxygen level now you need to sort it out to keep the plants and fish healthy. It would be best to add an aerator to your pond. It will help the aeration process which ultimately helps to increase the oxygen level of your pond.

4. Diversification of Plants

To make your garden pond look more attractive and colorful, you need to install a wider array of aquatic plants.

A pond filled with a single species looks monotonous and a boring sight for the eye. It is also harmful to your pond. Because if any plant gets disease then the rest of the plant will most probably die.

Diversification of Pond Plants

Moreover, by keeping more variety not only increases the amenity but also decreases the chance of plant death.

Aquatic plants like Creeping Jenny, Pickerel Pond Plant, Taro Pond Plant, Blue Iris, Mosaic Plant, Cardinal Flower, and Water Lilies will fully change the overall view of your pond and will make it vibrant and colorful.

5. Imbalanced Pond Chemical

Let’s digest the fact that- aquatic plants don’t simply like a pond filled up with chemicals. It’s a bit harder for the plant to survive in chemical mixed water.

After all, your pond is not just a water body, it’s a live ecosystem. It might be small compared to any natural lake. Though most of the chemicals are not harmful for fish, if you mistakenly add anything deadly without reading the label then it would be a total nightmare for you.

Not only that you will lose your plant but also your precious fish. You should try your best to ignore the use of any kind of chemicals unless it’s a must. And when you are bound to use then try to use the Eco-friendly one.

Additional Read: Best pond dyes

6. Temperature

Maintaining the right temperature is crucial for the life of pond fish and plants. A healthy temperature range of a pond is around 65-75 degrees. If you can maintain this temperature it will help the ecosystem of your garden pond.

However, in the harsh summer and winter season maintaining proper heat is quite challenging. But at least in winter you can buy and install a pond heater and de-icer to balance the heat. Unfortunately, in the summertime, there is no option yet.

7. pH Level

As a pond owner, you should keep the pH level of the pond between 6-8. Anything more or less than this level is a great threat for you. Your pond plants will easily die because of any imbalance of the pH level of water for a long time.

So you need to check it regularly. The problem is when the pH level is more than 7 means water is more alkaline and when it’s below 7 means it is acidic. You can easily buy a water testing kit and keep an eye on the pH level.

The water testing kit is not only limited to the measurement of pH level but also helps to measure the nitrates and ammonia levels. It will take only around one minute to find the result.

By checking the pH level you can save a large number of pond plants from dying.

Additional Read: How to lower PH in pond with fish

8. Depth of water

The variation of aqua plants can be seen in the survival of the plants on different levels of water. Many of them need to be submerged fully while others need to be floated on the surface.

Marginal pond plants are another type that need their roots and crown to be completely under water. A deep marginal pond is also close to the previous one but they can adapt to live in deeper water and their leaves have to remain above the water surface.

Floating pond plants are the easiest to maintain. Because you can keep them both on shallow or deep water surfaces.

It’s very important to place them at the correct depth of the pond. If you are confused as to why your plants are not growing so well then you should check whether you have placed them according to their requirement.

To help you with this, I am giving you some examples below so that you can easily put them in the required zone.

Types of PlantsDepth RequiredPlant Names
Submerged pond plantsGrow in 16’’ deep waterWater Lilies, Hornwort,  Cabomba, Mermaid Plant, Lemon Bacopa,  Mint Charlie, Anacharis.
Marginal pond plantsGrow in 6’’ deep waterJapanese Iris, Papyrus,  Grassy arrowhead, Water Violet, Marsh Woundwort, Marsh Marigold, Barred horsetail, Iris Louisiana.
Deep Marginal pond plants –Grow in 6’’-16’’ deep waterCattails, Pickerel Plant,  Amphibious bistort, Golden Club, Water Hawthorn, Fringe lily.
Floating pond plantsGrow in surface waterAzolla, Water lettuce,    Watermeal, Common Salvinia,  Water Hyacinth,   Giant Duckweed, Floating Crystalwort.


Additional Read: How to plant water lilies in a deep pond

9. Predator Fish

Some of your pond fish might have an interest in your pond plant.  For you, the pond plants are a means of beautification but for some fish, it’s just another food on their list.

Koi fish are especially well known for eating water lilies. Koi fish simply ripped off some of the parts of your pond plant which ultimately is harmful to them. Most of the time the root of the plant gets under attack first.

But don’t worry there is a solution to this problem. You just need to make sure there is a net barrier between the plants and fish. As a result, both plants and fish will be benefited in the long run. And if you are determined to avoid the use of any barrier then choose fish that are not going to eat your pond plants.

Read More: Can you keep Perch in a garden pond

10. Algae

Everything has a carrying capacity. So does your pond. If there is too much plant in your pond then there will be a shortage of nutrients. There is a solution and that is to add more fish.

Fish will consume algae from your pond which will create balance in the ecosystem. Moreover, they will also produce waste which will become a high source of nutrients for your plants. By applying this you can save your plant from dying.

Additional Read: Best pond plants to control algae

11. Water Disturbance

Different pond plants react differently to the water splashing from the waterfall. There is no doubt that waterfall is good for generating oxygen in the water but some pond plants simply can’t tolerate the movement of water or continuous stream.

You need to understand which plant you can keep close to a waterfall and which one to place far from the waterfall. For example, water lilies usually grow in water that is stagnant water. So keeping them close to the waterfall will force them to become yellow and they will die later on.

Additional Read: How to add waterfall to a pond

12. Insects

Insects have a high interest in plants. They will just eat your pond plant and prevent the proper growth. Among the insect world, a specific insect called Aphids usually attacks pond plants. You may find them on your pons floating plants.

It’s not very tough to deal with this insect. You can just spray water and it will fall into the pond. A moment later it will become the food of your fish.

13. Lack of fertilizer

A yellow leaf pond plant is also an indication that it is suffering from a lack of nutrients. Which means that it needs fertilizer for proper growth.

If it’s a bog plant then just inject some fertilizer into the soil. But if it’s floating pants then you need to remove them from the pond. Then put it into a jar or container full of water.

Now you can add your plant’s required water-soluble fertilizer and it helps the plant to get back its old color.

When you want to feed your deep-rooted submerged pond plants then you can use pellets to inject under the base soil for the proper fertilization.

Final Words

Just don’t become hopeless if you see your favorite plants are dying. Because there are practical solutions and now you know it.

I hope by this time, you have precise info on your mind which will help you to understand why your pond plants die and what to do.

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