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7 Reasons Why Hydroponic Plants Are Wilting (And How to Fix It)

A lot has already been said about hydroponics and it would seem that there should be no lack of information for beginners. However, I found a topic that has not yet been fully disclosed, and so I decided to write this article.

The main cause of wilting of hydroponic plants is root rot. The diseased roots are unable to supply water to the leaves and the plant wilts.

Other causes of leaf drooping are inadequate root moisture, disease, or inadequate water temperature. All of these cases and several others are discussed in detail here.

Root Rot

hydroponic plants wilted because of root rot

Root Rot

Sometimes it happens that the roots of hydroponic plants can start to rot. In fact, this is not at all surprising since the root system is constantly in water.

The first indication that there is trouble with the roots is the drooping of leaves and petioles. The second symptom is brown and mushy roots.

If this is your case, pull all the plants out of hydroponics and remove the rotten part of the roots. Severely damaged plants are best to throw away.

Dilute 100 milliliters of hydrogen peroxide in a gallon of water and immerse the plants in it for one minute. Then pull them out and rinse them in clean water.

Drain the water from the hydroponics and clean the system well. Pour in fresh water and add some hydrogen peroxide. Turn on the system for 10 minutes and then drain off this solution.

Add fresh water and nutrients and put the plants back in place. Install air stones with a powerful air pump in your hydroponics.

How to avoid root rot:

  • Change the water in your hydroponics twice a month. Use distilled water or purified water with an ultraviolet sterilizer.
  • Avoid overheating the nutrient solution.
  • Ensure good oxygen saturation.
  • Clean your hydroponics regularly.

Read also: What hydroponics system is the best?

Wilting after water change

Leaf drooping of hydroponic plants is also possible after water changes. You may have changed the water or cleaned the system and noticed that the leaves have become stiff and saggy after putting the plants back in place.

This could be caused by different water. For example, you used distilled water before and then decided to change it to tap water. Also, you may not have adjusted the pH value of the water or the temperature of the freshwater may have been different from the old water.

Plants in general do not like sudden changes and react with stress. The plants should go back to normal after a while, but you may still lose some of them.

To avoid this in the future use the same water as before, adjust the pH, and provide the same temperature as before.

Another reason may be that you kept the plants for too long without water when you were cleaning the system.

The next time you change the water or clean the system, put the plants in a different tank of water. This will prevent the roots from drying out quickly and the leaves from wilting.

Wrong water temperature

hydroponic plants drooping because of wrong temperature

Too hot water.

Next is the temperature of the water. If it is too hot or too cold, the plants may become stressed, which will cause the petioles and leaves to droop.

A very common case is overheating hydroponics. This usually happens because the water pump gives off heat and the water heats too much. It is also possible that the tank is placed in direct sunlight, which also heats up the solution.

The high temperature can lead to slime on the roots. This will make the plant sick. But if the temperature rises even higher, the plant will get a temperature shock and wilt.

The opposite situation is also possible. This is when the water in the hydroponics is too cold. The colder it is, the slower the plant grows. But if the temperature drops very sharply, the plant may get stressed and die.

How to fix this:

  • Keep the hydroponics water temperature between 59-72°F (15-22°C)
  • Install a cooler or heater if necessary
  • Avoid drastic temperature changes in both the room and the tank
  • Eliminate cold drafts near hydroponic plants

Drooping after transplanting

hydroponic plants falling over after transplanting

Transplant shock

Replanting is very stressful for plants. If it is done incorrectly, the result can be drooping leaves or even loss of the plant.

If you move the seedlings from a nursery to a hydroponic system, they will probably lose internal pressure. Leaves, petioles, and even the stem may become soft and the plant will sag.

This is quite common and may be considered normal. After some time the plant will adapt to the new environment and recover. However, some plants may not survive and this is also normal.

To reduce the shock of transplanting you need to follow these guidelines:

  • Only transplant plants when they already have a complete root system.
  • Avoid damaging the roots as well as the top of the plant.
  • When transplanting, do not leave the plants without water for a long time.
  • Try to replicate the conditions of the previous location.

Power outage

hydroponic plants wilted because of the lack of electricity

Power outage

One of the problems with hydroponics is that most of its types are dependent on electricity. This dependence makes the plants very vulnerable.

For example, you go to work and the power goes out at your house. If the system doesn’t supply water to the roots for a few hours, the leaves will droop. It is also possible that some plants will die.

Those that survive may become leggy. It is also possible that they will start to flower. All of this will be the result of stress due to the lack of water.

To avoid this, choose hydroponics that is less dependent on electricity. An example is the Kratky method.

Another way to solve this problem is to install a backup power supply. This can be either a battery or a gasoline generator. A more environmentally friendly solution is solar panels.

Inappropriate pH or EC

The unsuitable nutrient solution can lead to problems with hydroponic plants.

The first is the pH of the water. If this does not meet the requirements of the plants, there may be a lack of nutrients and the leaves will turn yellow and droopy.

The second is the EC of the water. Again, if it is not suitable, the plants may suffer. This is especially true if there is too much fertilizer in the solution as this can cause root burn and wilt of the plant as a whole.

Plant Optimal pH Optimal EC
Artichoke 6.5-7.5 0.8-1.8
Arugula 6.0-7.5 0.8-1.2
Asparagus 6.0-6.8 1.4-1.8
Basil 5.5-6.5 1.0-1.6
Bean (Common) 6.0 2.0-4.0
Beetroot 6.0-6.5 0.8-5.0
Bok Choi 6.0-7.0 1.5-2.5
Broad Bean 6.0-6.5 1.8-2.2
Broccoli 6.0-6.5 2.8-3.5
Brussell Sprout 6.5-7.5 2.5-3.0
Cabbage 6.5-7.0 2.5-3.0
Capiscum 6.0-6.5 1.8-2.2
Carrots 6.3 1.6-2.0
Cauliflower 6.0-7.0 0.5-2.0
Celery 6.5 1.8-2.4
Cucumber 5.5-6.0 1.7-2.5
Eggplant 5.5-6.5 2.5-3.5
Endive 5.5 2.0-2.4
Fodder 6.0 1.8-2.0
Garlic 6.0 1.4-1.8
Kale 5.5-6.5 1.2-1.5
Leek 6.5-7.0 1.4-1.8
Lettuce 5.5-6.5 0.8-1.2
Marrow 6.0 1.8-2.4
Okra 6.5 2.0-2.4
Onions 6.0-6.7 1.4-1.8
Pak Choi 7.0 1.5-2.0
Parsnip 6.0 1.4-1.8
Pea 6.0-7.0 0.8-1.8
Pea (Sugar) 6.0-7.0 0.8-1.8
Pepino 6.0-6.5 2.0-5.0
Peppers 5.8-6.3 2.0-3.0
Peppers (Bell) 6.0-6.5 2.0-3.0
Peppers (Hot) 5.0-6.5 3.0-3.5
Potato 5.0-6.0 2.0-2.5
Pumpkin 5.5-7.5 1.8-2.4
Radish 6.0-7.0 1.6-2.2
Spinach 6.0-7.0 1.8-2.3
Silverbeet 6.0-7.0 1.8-2.3
Sweet Corn 6.0 1.6-2.4
Sweet Potato 5.5-6.0 2.0-2.5
Taro 5.0-5.5 2.5-3.0
Tomato 5.5-6.3 1.5-3.0
Turnip 6.0-6.5 1.8-2.4
Zucchini 6.0 1.8-2.4

To avoid this you need to make the right solution. To do this you will need a special device that measures both the pH and the EC. Then use the table above to make the right solution for your plants.

Plant Diseases

hydroponic plants are droopy because of fusarium wilt

Fusarium Wilt

And the last possible cause of hydroponic plant wilt could be disease. The most dangerous is the Fusarium wilt.

The pathogens of this disease parasitize the plant by destroying the living tissue. The plant wilts quite quickly and dies.

To date, there are no effective treatments for this disease. Multipurpose fungicides can improve the situation a little, but they will make the vegetables inedible.

If your hydroponic plants have wilted because of Fusarium wilt, it is best to throw them away. Next, remove the solution and clean the system well. Thoroughly treat all parts of the hydroponics with hydrogen peroxide.

To avoid this disease in the future:

  • Keep your hydroponics clean.
  • Sterilize the water before filling the tank.
  • Check plants for a disease before putting them in the hydroponic system.
  • Ensure good ventilation in the hydroponics room.