One of the many benefits of hydroponic gardening is that you’ll likely experience fewer pests and diseases. When growing indoors in a closed system, growers can take more control of the environment, but this doesn’t mean your plants will be totally
immune to those tiny invaders.
Where there are luscious green plants, you can be sure there are pests waiting to make a home! If they do find their way into your setup, unfortunately they will lack the natural competition that exists in a regular garden, meaning a small pest problem may turn into a major issue if left unattended.
Here are 6 common pests you may come across during your hydroponic journey, and our advice on what to do about them.
Aphids are resourceful little critters – they can be born pregnant, and don’t need a
male to reproduce, meaning that a colony can start from a single insect. Once the
colony has grown, they will start to produce flying aphids in order to find new host
plants, which is how they may find their way into your hydroponic setup.
An aphid infestation can be deadly to your plants. They can spread viral plant
diseases and suck sap causing your plant to wilt, whilst attracting sugar-loving ants.
Plants that are overfed with high nitrogen synthetic fertilisers are particularly
susceptible to aphids.
While their rapid reproduction rate makes them hard to get rid of, they have soft
bodies and are easily squashed or killed with insecticidal soap, and you can even
use live ladybugs to devour the aphids.
True to their name, Spider Mites produce fine webs which they use for protection
and to travel from leaf to leaf.
Make sure you tackle spider mites quickly and isolate any infected plants, as they
develop large colonies very quickly. They will suck juice from your plants, leaving
weak, speckled leaves.
Spider mites prefer dry environments, so a highly humid grow room should keep
them at bay.
Attack spider mites with neem every few days and keep a close eye on your plants for any sign of return. Wettable Sulphur is also very effective for preventative measures and larger infestations.
These minuscule white insects will suck the life out of your plant, while producing a
fluid that can breed mould. In fact, the mould may be the first sign you notice.
You can attack these insects using chemical-free methods like sticky traps, neem oil
and releasing parasitic wasps that feed on whitefly nymphs, while raking the small
eggs from leaves.
You are more likely to notice the damage thrips have caused before you spot these
tiny, fast insects. They cause older leaves to appear silver and scaley, and new
leaves and fruit to grow distorted.
You can tackle thrips by spraying with pyrethrum or neem and cutting off a stage of
their life cycle by blocking the roots with plastic. You can also scrape off the small
white eggs and crush them.
The small, white and “furry” looking insect will make a permanent home of its chosen
plant and suck the life out of it.
Their hard shell makes them difficult to kill with insecticides, so its best to attack the
younger generations without this defence. A slow yet effective method to get rid of
mealy bugs is to swab the adults with alcohol, and attack the younger insects with
pyrethrum, whilst being sure not to overwater or over fertilise.
Fungus gnats look a lot like whiteflies, and while the adults won’t damage your
plants, the maggot-like larvae will destroy your roots and your plant will quickly
display signs of nutrient deficiencies. Once they have infested the roots, it is unlikely
that you will be able to save your plant.
Fungus Gnats are attracted to algae and dead matter, so using alga-killing treatment
and removing old plant material will help. You can use sticky traps, neem oil,
insecticidal soap, and pyrethrin to attack the adults. Low dilution hydrogen peroxide
can also work, but make sure you’ve done your research as this can burn your
Remember, prevention is always the best cure, and it’s important to practice healthy
propagation hygiene when it comes to your hydroponic setup. Avoid bringing in tools
from your outdoor garden, as these can introduce pests and their eggs into the
Make sure all possible entry points are covered and
protect vents with insect proof netting. Once you do notice a pest infestation, the key is to tackle it immediately. Insects
reproduce quickly and by the hundreds, so you may find yourself with serious problem sooner than you think.