Many greenhouse growers have turned to hydroponic gardening to increase both yield and quality of their veggies or ornamentals. Most of the essentials such as light, air movement, humidity, and temperature are the same as for other plants. The big difference is the soil (or lack of it). This can influence which pests you might encounter and how to deal with them.
Nearly all pests such as Spider Mites, Whiteflies, and Aphids can be a problem in hydroponic systems just like they can in soil. You control them the same way as you would in soil. You only need to change your pest control strategy when the pests have a stage in the media. Thrips, Fungus Gnats, and Root Aphids are some pests commonly pests found in hydroponic systems. Medias such as rockwool and coir coco-fiber seem to offer a suitable home for larvae stages of both Thrips and Fungus Gnats.
Systems with clay pellets or even no media at all (aeroponic) can still sustain pest larvae that would normally live in soil. Root Aphids love to cling to bare roots and slowly suck their juices. Predatory Nematodes can still be used for control, but they tend to get rinsed into the reservoir where they drown. In soilless systems larger quantities must be applied more often to get good results. Fungus Gnat Predators can be harder to rinse into the reservoir which makes them a good option for some hydroponic systems. Neem Oil drenches through the media can also help, as can Hydrogen Peroxide solutions. You must be very careful with Hydrogen Peroxide. There is a fine line between harmful to pests and harmful to roots so proper dilution rates are a must.
Springtails are another common hydroponic pest. They are attracted to the moisture and can show up by the thousands overnight! They don’t do a lot of damage, but they are an unsightly nuisance. Fungus Gnat Predators are recommended for control. You should also find out where they are coming in from and try to seal it up with caulking or spread some Diatomaceous Earth.
Cleanliness is very crucial to having a pest free and trouble-free hydroponic system. Any dead leaves and organic debris need to be quickly removed before they encourage pests or root rot. Between crops every piece of equipment including pumps, trays, reservoirs, and media should be thoroughly cleaned and sterilized. Bleach or hydrogen peroxide solutions are an inexpensive and effective way to sterilize your equipment. If you have a pest problem, you may want to drain and sterilize your system in the middle of a crop. This can eliminate many of the pests and make your hired bugs work more efficiently.
Hydroponic gardening can be rewarding and profitable. Simple things like regular inspections of roots and foliage combined with cleanliness can save your plants, save money, and provide bountiful harvests!
Nathan Jackson is the owner of Nature’s Control and Ladybug Indoor Gardens. You can send your specific bug questions to firstname.lastname@example.org. For more information, to request a catalog, or to find a local distributor, check out Naturescontrol.com or call 541.245.6033.