How To Get Rid Of Hydroponic Pests In Your Garden

You can using predators as a control measure, parasitoids, and crop rotation to help you get rid of hydroponic pests. In extreme pest attacks, try to uprooting the plants or applying chemical control.

Hydroponic gardening continues to gain popularity worldwide. The fact that you can set up these systems virtually anywhere and you are not limited to certain conditions such as fertile loam soils makes them ideal for most urban farmers.

However, like any other form of gardening, hydroponic crops are susceptible to pest and disease attacks. In this article, we will discuss the most common hydroponic pests in your hydroponic garden, their control, and possible preventive measures.

Let’s get started.

Hydroponic Gardening Pests in a Nut Shell 

We can define pests as organisms that alter the economic outcome of agricultural products negatively. These hydroponic pests are classified into two broad categories:

hydroponic pests
A Caterpillar Eats A Green Leaf

Microscopic Pests

These cannot be seen by a naked human eye. They are probably the most notorious, and they are also the most difficult to eradicate. They include bacteria, viroids, fungus, and virus. Their symptoms might resemble each other, but with a keen eye, you will notice the difference. We will discuss them in detail shortly.

Macroscopic Pests

As the name suggests, these are big in nature, and even the tiny ones can be easily identified. They include all invertebrates (annelids, insects, and nematodes), cats, rats, snakes, and mice. You probably never imagined that cats, snakes, and mice could be a threat to your hydroponic garden, did you? Well, now you know.

Note: It is important to mention that not all pests are harmful. Some are beneficial, and you need to somehow include them in your system for optimum yields. 

The Pests in Detail

In this section, allow me to get a little bit technical. We will start with the invisible vicious creatures.

hydroponic pests
Microscopic Pests

1. The Microscopic pests in Hydroponic Gardening


If you love mushrooms, beer (lager), and bread, then you have first-hand experience with the fungi kingdom. Yes, mushroom and yeast are fungi. But this is not our key focus today. Most farmers have dealt with fungus mostly in the form of mold patches which form on the leaves.

Harmful Fungi
  • Basidiomycetes: A key member is the Ustilago species commonly referred to as smuts and the Rhizoctonia species that cause girding lesions on fruits such as the cucumber.
  • Oomycetes: You might have experienced the Peronospora belbahrii that causes downy mildew in hydroponic basil.
  • Ascomycetes: The common one under this category is the Botrytis cinerea which causes gray mold on leafy green vegetables. Then the Anthracnose causing fungus called Colletotrichum orbiculare. Anthracnose is commonly identified by blotches, multiple spots on leaves, distortion, and leafless plants or deprived of leaves, and shoot blight among other symptoms.

Note: By species, we mean a broad category of pathogens all falling under the same family biologically. Therefore, you might come across several names referring to the same species.

Like the Rhizoctonia solani falls under Rhizoctonia species and it is the specific fungus responsible for girding lesions. But for the basis of understanding the concept, allow me to discuss them in general.

Beneficial Fungi 

We mentioned before that not all hydroponic pests are harmful. We have beneficial funguses which include: Botrytis cinerea. This is responsible for the noble rot (grey fungus) in grapes that is common in moist weather conditions, and mycorrhizae species which attach to plants roots, as well as yeasts.

Sanit​​​​ation is effective in Fungus control. Sterilize your equipment often between stations and use appropriate sanitation at the garden entry. You could also apply organic fungicides.


Harmful Bacteria

The harmful bacteria fall in the family of Psuedomonas syringae which has over 50 variants. Luckily almost all bacterial infections have a chemical cure. So these will tend to bother the organic farmers most. They also have unique symptoms and are easily identified.

Harmful Bacteria On Leaves
Harmful Bacteria On Leaves

The harmful bacteria fall in the family of Psuedomonas syringae which has over 50 variants. Luckily almost all bacterial infections have a chemical cure. So these will tend to bother the organic farmers most. They also have unique symptoms and are easily identified.

Beneficial Bacteria 

On the other hand, Rhizobium species (asymbiotically fixes nitrogen), Baccilus thuringensis (the larvacide), and Frankia species (non-symbiotically fixes nitrogen) and several others are beneficial bacteria.


These are notorious in causing plant deformities, death, and naturally low yield. Viroids are categorized into two families:

  • Avsunviroidae: these attack mainly eggplants, avocado trees, and peaches.
  • Pospiviroidae: Responsible for infections on apples, potatoes, coconut, tomatoes, hops, and citrus trees, as well as on the individual fruits.

The best solution to viroids is by planting transgenic plants and using viroid-free propagules, as well as controlling the vectors. But in the event of a viroid attack, apply phytosanitation and quarantine to manage the disease.


Viruses are the worst in this category. They cause diseases and infections that spread rapidly and most of these diseases have no cure. Viruses are also known for plant deformities and death. The ultimate cure for viral attacks is uprooting the entire infected plant and keeping off from planting any other crops in the same family as the infected one for a year or two.

2. The Macroscopic pests in Hydroponic Gardening

In this category, the use of predators and parasitoids as control measures are notably effective.

Lettuce Eaten By The Cabbage Worms
Lettuce Eaten By The Cabbage Worms


Biologically speaking, invertebrates are any organisms without a notochord. The notorious pests under this category include:

Harmful Invertebrates
  • Roundworms (Nematoda): The harmful ones act as virus vectors while others feed on plant leaves and roots (like the root-knot nematode). To prevent roundworms attack, deal with the vectors (pets and rodents). In addition, replacing the attacked crops with non-susceptible host plants and intercropping with Marigolds are viable solutions.
  • Roaches (Blattodea):  These feed on decaying organic matter. In a hydroponic system, it is almost impossible to do away with decaying matter. Therefore, the best solution to roaches is to trap them using borax box baits. You could also remove (or reduce) organic plant waste and debris in places without growing crops.
  • Aphids, mealybug, whiteflies, and scale, (all classified as Homoptera): These are significant pests because they bring about diseases, carry and spread viruses, as well as cause major crop damage. To avoid these pests, pay attention to healthy cultural practices; for example, reducing the use of nitrogen fertilizers. And if the farm is already infested, use appropriate horticultural oils to smother them, and natural predators.
  • Flies (Diptera):  Fly pests are in different forms and shapes. They also feed on diverse substances. For example, the Fruit fly infests overripe fruits, and their favorite is hydroponic strawberries. Fungus gnats, on the other hand, love feeding on the roots. Their major problem, however, is inviting diseases. These you can control by having a well-dried media in between the wetting intervals. Overall, flies can be controlled by planting herbs that repel them such as rosemary, lavender, basil, and lemongrass.
Beneficial Invertebrates

The beneficial invertebrates, on the other hand, include Predatory Nematoda (these kill corn earworm moths, cutworms, and other garden pests), Coleoptera, Hymenoptera (parasitoids), and some Diptera. As an example, parasitoids are beneficial in that they lay eggs in other harmful organisms. Afterwards, they feed on these organisms until they pupate.

Cats, rats, snake, and mice are obvious, aren’t they?

Other Solutions to Hydroponic Gardening Pest Attacks

In addition to those we’ve discussed above, you can practice the following:

  • Baking soda (Sodium Bicarbonate): Spray in powder or solution form to eradicate different forms of powdery mildew, rust, anthracnose (in cucurbits), and the dollar spot.
  • Oil sprays control leaf and gummy stem blight especially in muskmelon and urocladium leaf spot, especially in cucumbers.

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Final Thought

Hydroponic pests tend to thrive when the conditions around them favor their growth. And if not controlled in time, they can bring diseases. If you’re practicing organic farming, using predators as a control measure, parasitoids, and crop rotation should be of help.

However, in extreme pest attacks, uprooting the plants or applying chemical control is the most feasible solution. While using the latter, you need to be careful not to contaminate your hydroponic solution or else you risk losing the entire garden.  

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