4 Common Indoor Gardening Pests and how to Nuke ’em (Naturally)
Our planet is one giant Ecosystem. Whether plants, animals, or fungi, organisms tend to exist in a stable balance unless acted on by an outside force. These outside forces can vary greatly- invasive organisms can outcompete local native populations, chemical runoff can cause streams or watering holes to become polluted, or pesticides like DEET can cause secondary damage, not only killing the insects it was designed to, but also causing bird eggs to develop abnormally.
As caretakers of the ecosystem we call Earth, it’s our responsibility to preserve and work with this natural balance. For those of us who also look after ecosystems on a smaller scale, it’s also important for us to keep the creatures in our care safe and happy. That’s why we’d like to introduce you to a few of our favorite, cost-effective fish-safe (and people-safe) methods of controlling four of the most common indoor gardening pests.
1. Aphids
Among the most common pests in a home garden, Aphids come in a few colors (green, red, black, orange/yellow, and sometimes white) and resemble fat grasshoppers about the size of a grain of rice. Aphids eat plants by attacking leaves and sucking out nutrients the plants need to grow. They will quickly turn a healthy plant into an ugly shadow of its former self before they roam to find more food. Many types of aphids have wings to migrate from plant to plant once they become too populous. Aphids also leave behind white shells when they molt. These and the presence of a sooty, discolored substance on the surface of the plant are the two telltale signs of an aphid infestation if you don’t see the critters themselves.
Unfortunately, in addition to being one of the most common garden pests, they can also be one of the most tenacious. Getting rid of aphids completely can be a tough battle in aquaponics, where many of the most effective insecticides are not fish-safe. However, aphids have several natural predators including ladybugs and lacewings, which are some of the cheapest effective options for controlling an infestation. They can be purchased online and shipped directly to your doorstep. Other methods of control such as insecticidal soap or neem oil may be used, but great care must be taken to cover the growbed completely and avoid overspraying in order to keep them from getting into the water and harming your fish.
2. Fungus Gnats
Fungus Gnats are a pest that many people with houseplants in soil will recognize immediately, though they are often misidentified as fruit flies. They are small, black, two-winged flies that thrive in the conditions where fungus is present: when there is decaying organic matter that stays moist. However, fungus gnats don’t just eat fungus- they also have a tendency to snack on young plant roots, which can cause serious problems for starting seedlings. While they will seldom be enough to kill healthy adult plants on their own, they can drastically increase the rates of damping off, which is an often fatal condition where live plants will start to decay from the very bottom of their stem.
Fear not, though! Fungus gnats are one of the more easily controlled pests common to indoor gardening. They can often be defeated without the use of pesticides simply by taking care to remove dead plant leaves and roots from the growbed. Additionally, cutting off the other resource they require to thrive- water can help contain them. By shortening the amount of time your growbed stays wet (or cutting down on how often you are watering in soil), you can often deal a crippling blow to a population of fungus gnats. They can also be kept under control by putting yellow sticky traps near your plants, especially near newly germinated seedlings. In particularly severe infestations, you can use a natural bacteria called B.T. to eradicate them. B.T. is easy to find in many hardware stores and garden centers regardless of the time of year. It is the main component of mosquito dunks, and is also used to control caterpillars, grubs, and other insects.
3. Thrips
Thrips are a particularly nasty garden pest that can kill your plants outright, but will certainly make them look haggard long before that happens. Unlike the other pests on this list, thrips can be a nuisance for gardeners as well as their plants since some species are known to bite humans. Many types of thrips change colors as they transition from juvenile to adult, often starting white or pale colored and ending up dark brown or black. Rather than flying, thrips tend to hop like grasshoppers, using their wings to give them an extra boost mid-leap. When they feed, they leave a golden or copper looking trail on the leaves of plants, but in aquaponics systems they will seldom be seen on the plants themselves. If you see this sort of damage on plants, it’s worth turning over the top layer of your growth medium (or flooding your growbed, since they float!) to check for thrips.
Thrips are another particularly tough pest. They can survive for long periods of time without food, so even pulling up your plants is not enough. They also leave eggs that hatch every few days, so even killing a full generation of thrips is not sufficient. Though the situation may seem dire if you find thrips in your system, don’t panic! They can be killed using purified spinosad, which is a purified extract of a chemical the bacteria B.T. produces. It will take several applications (done several days apart) to take them down, but by eliminating hatchlings before they reproduce they can be dealt with in a way that is safe for your plants, your fish, and you.
4. Spider Mites
Spider Mites are another incredibly common pest that people tend to miss due to their small size (pinhead or smaller). As their name suggests, the mites resemble miniature spiders- both visually, as well as behaviourally. Much like spiders, spider mites will spin webs on the leaves of your plants. Unfortunately, unlike spider webs, mite webbing smothers plant leaves and allows mites to spread between plants very quickly. As they feed, they will leave coppery colored shiny spots on leaves which is can be quite unsightly, and can kill a plant if the mites are not dealt with.
Luckily, Spider Mites are among the easiest pests to manage if you catch them early. The main way of eliminating spider mites is what we call “cultural control”, which is when you change the environment a pest is living in to reduce the presence of pests. They tend not to do well in high humidity, so putting your plants under a humidity dome or next to a humidifier can be incredibly effective.
Destroying their webbing can drastically slow the spread of spider mite colonies, so removing the webbing with your hand and keeping the environment humid might be all it takes. If you wish to accelerate the removal process of spider mites spinosad is also an effective way to get rid of them.
So there you have it, four common indoor gardening pests and how to nuke ’em (naturally). Remember, the most important thing to do when you discover the presence of pests in your indoor (or outdoor) garden is to not panic! Pests are bothersome but easily conquered by a little patience and human ingenuity. If you would like to chat or share your experiences with pests please drop us a line at ecology@grovelabs.io, we are always here to lend a helping hand in the pursuit of delicious, healthy, homegrown produce!
Originally published at blog.grovelabs.io.
