How to Get Rid of Aphids on Pot Plants
Aphids are one of the most common and destructive pests that can attack cannabis plants. These small, sap-sucking insects can quickly get out of control and devastate your crop if left unchecked. Getting rid of aphids requires diligence and persistence, but it can be done organically and safely using integrated pest management techniques. In this comprehensive guide, we’ll cover how to identify, prevent, and control aphid infestations on pot plants.
What Are Aphids?
Aphids are tiny, soft-bodied insects that use their straw-like mouths to pierce plant tissue and feed on sap. They come in many colors like green, yellow, brown, red or black. Aphids often cluster on the undersides of leaves or on new growth. An infestation usually starts when winged aphids land on plants and give birth to live young. These nymphs mature in just 7-10 days and begin reproducing rapidly themselves. A single female can produce up to 60 offspring in her lifetime! This leads to explosive population growth, allowing the colony to quickly get out of control.
Aphids secrete a sticky substance called honeydew that coats plants. This honeydew attracts sooty mold fungus and other pests like ants. Aphids can also spread viruses as they feed. For all these reasons, it’s critical to get rid of aphids as soon as they’re spotted. Catching an infestation early makes treatment much easier.
Signs of Aphids on Pot Plants
Here are some telltale signs that aphids have invaded your cannabis garden
-
Tiny white spots that look like eggs or larvae on leaves
-
Clusters of small, oval-shaped bugs on undersides of leaves
-
Leaf yellowing curling stunting. or wilting
-
Presence of ants, honeydew, or sooty mold
-
White shedded skins leftover from molting nymphs
-
Winged green, black or yellow aphids flying around
Thoroughly inspect plants at least once a week to detect infestations before they get severe. Pay extra attention to young leaves and flowering sites which aphids prefer. Take action at the first sign of trouble to nip it in the bud.
How to Get Rid of Aphids Naturally
If you catch an aphid infestation early, there are several effective organic control methods:
Insecticidal Soaps – Insecticidal soaps containing potassium salts of fatty acids will kill aphids on contact by disrupting their cellular membranes. Spray all parts of the plant, especially the undersides of leaves where aphids hide. Apply every 5-7 days for 2-3 weeks until aphids are gone. Rinse plants after application to prevent leaf burn. Brands like Safer’s Insecticidal Soap and Garden Safe Insecticidal Soap are OMRI certified for organic use.
Neem Oil – Neem oil is an organic pesticide that smothers and kills aphids. It also acts as a repellent. Mix neem oil with warm water and a bit of mild soap. Thoroughly spray infested plants, including stems and undersides of leaves. Reapply every 7-10 days for a few weeks. Don’t spray neem oil during flowering or onto buds.
Horticultural Oils – Lightweight horticultural oils like soybean, canola, or cottonseed oil will coat aphids and suffocate them. Mix according to label directions and completely cover infested plants. Horticultural oils also help deter aphids from returning. Avoid spraying flowers or buds directly.
Pyrethrins – Pyrethrin insecticides are derived from chrysanthemum flowers and effective against soft-bodied insects. Products containing pyrethrin combined with canola oil work well to knock down aphid populations. Spray plants thoroughly and repeat every 5-7 days as needed. Use caution and avoid buds when spraying.
Diatomaceous Earth – Diatomaceous earth (DE) is a powder made from fossilized algae that abrades the waxy coating on insect exoskeletons, causing dehydration. Dust leaves with food grade DE using a duster. Focus on the undersides of leaves and reapply after rainfall. DE is non-toxic but avoid breathing in the dust.
Insecticidal Fungus – Beneficial fungi like Beauveria bassiana kill insects by penetrating their bodies and releasing toxins. These spores work by direct contact so completely coat all plant surfaces. Apply in the evenings when less UV light is present. It may take several weeks to see results. Brands like BotaniGard and Mycotrol O are organic and approved for cannabis.
Predatory Insects – Release natural predators like ladybugs, lacewings, minute pirate bugs, and predatory mites which feed on aphids. They offer longer-term suppression by establishing populations in your garden. Use preventatively or at first signs of aphids. Lacewings or lady beetles are especially effective against heavy infestations.
Blast With Water – For small infestations, simply spraying aphids off plants with a strong jet of water can help dislodge colonies and reduce their numbers. Focus on the undersides of leaves where they tend to hide. Follow up with an organic pesticide to kill any stragglers.
Quarantine & Prune – Remove badly infested leaves or entire plants as needed to prevent spreading. Prune off buds with heavy aphid populations. Monitor other plants closely for signs of infestation. Quarantine and treat new plants before introducing to your grow area.
How to Prevent Aphids
An ounce of prevention is worth a pound of cure when it comes to aphids. Here are some tips to help keep them away:
- Inspect plants frequently to detect infestations early
- Remove weeds which can harbor aphids
- Use preventative sprays like neem oil or insecticidal soap
- Release beneficial insects before issues arise
- Use row covers or greenhouse walls as physical barriers
- Rinse off plants with water to disturb colonies
- Don’t over-fertilize plants – high nitrogen attracts aphids
- Apply kaolin clay sprays which deter pests from feeding
- Use yellow sticky traps to catch winged aphids before they reproduce
Aphids can be tricky to get rid of but with early intervention, persistent monitoring, and repeated applications of organic pesticides, you can protect your cannabis crop. Combining multiple control methods together works best to knock down infestations. Always follow label directions closely when using any pesticide on marijuana plants. With diligence and patience, you can safely get rid of aphids and keep your pot plants healthy and productive.
What Causes an Aphid Infestation?
Your plant can become infested when winged “colonizer” aphids land on the plant and lay eggs. Although you may not see the winged version of an aphid actually eating your plant, they are still dangerous because they can lay eggs and start a new aphid colony! Winged aphids are sometimes called “blackfly” or “greenfly” bugs depending on the color (because they are often black or green/yellow, and they look like tiny flies).
Aphids are sometimes called “Green Flies” or “Black Flies” when they have wings, but the general body shape is the same. The winged versions appear when the aphid colony gets too numerous and these bugs use their wings to fly away and lay eggs on other plants. This “black fly” is actually a winged aphid.
This “green fly” is another color variation of a winged aphid
It’s difficult to prevent aphids from getting to your cannabis plants outdoors as just a handful of winged aphids is all it takes to start an infestation. The eggs soon hatch into a juvenile form of aphids called “nymphs,” which happily start munching on your plant.
This grower started seeing white specks on their buds and thought it might be mold or bud rot. The specks were actually white aphid nymphs. Click the picture for a closeup!
Immature aphids (nymphs) usually appear white and feed on plant sap while they gradually increase in size.
The aphid nymphs mature in 7 to 10 days and shed their skin, leaving silvery exoskeletons behind on your plants. Note: If you see tiny white bugs but they look round, fat and more worm-like than these ones, you may actually have thrips.
The bottom center aphid is actually in the middle of shedding its exoskeleton in this pic.
After reaching their wingless adult form (aphids don’t grow wings when actively colonizing your plant) they are soon ready to give birth to live young and start the process over again. Most aphids in this form are female, and each one is capable of producing dozens of offspring.
Because of their quick reproduction, a few winged aphid “colonizers” can lead to hundreds or even thousands of aphids on a plant in just a few generations. A full-blown aphid infestation can get out of control in just a few weeks!
Aphids often keep reproducing on the plant until the plant becomes so stressed (or the conditions become so crowded) that the plant can no longer support their ravenous appetites. At that point, some of the aphids start being born with wings, and these winged aphids fly off in search of a new host, starting the process over again on a new plant victim.
How to Identify Aphids on Cannabis Plants (also called greenflies and blackflies)
Aphids are soft-bodied cannabis-loving insects which can appear white, green, yellow, black, brown, and red, depending on their stage of life and where they live. Because they’re so widespread they can be a cannabis pest almost anywhere in the world!
Aphids look very different depending on their stage of life. In this picture, the bigger, rounder bugs are adult aphids, while the white, smaller, thinner bugs are young aphids (nymphs). Note: If you’re seeing white bugs that look like tiny fat worms, you may actually have thrips.
Sometimes the aphids that attack marijuana are dark-colored or black. This bud is aphid city!
Here’s another example showing aphids of different colors and at different stages of life.
Sometimes when growers see tiny black flies or green flies on their cannabis, they’re actually seeing aphids with wings. Winged aphids can be dark or pale, and colors include green, red or yellow. However, the general body shape of the bug is usually pretty similar whether the aphids have wings or not.
Because many aphids that attack cannabis are green, sometimes people don’t recognize aphids when they’re a different color (like these young aphids which appear red)
These aphids from Europe are pale green with dark legs and red eyes
Aphids are a common cannabis pest. Adults are usually small and oval-shaped and may have visible wings or antennae. Nymph aphids are thin/long and usually white or pale. Because nymphs are so small, they may look like little white specks or eggs.
Aphids pierce cannabis leaves with their sucking mouth-parts and feed on the juices inside. They usually occur in colonies located mainly on the undersides of stems and leaves. If a cannabis plant becomes heavily-infested, its leaves can turn yellow and/or wilt due to excessive stress and leaf damage.
“Honeydew” and Black Sooty Mold
Another problem with aphids is they produce large amounts of a sweet substance known as “honeydew,” which is a sugary liquid waste. Honeydew drops from these insects attract a type of fungus called sooty mold. Sooty mold can grow on honeydew deposits, accumulating on the leaves and branches of your plant and turning them black. Not only does this mold discolor the plants and somewhat hinder normal plant processes, but sooty mold on buds can also make them unsafe to smoke. And just to be an extra pain in the butt, the drops of sweet honeydew can also attract other insects such as ants.
Get Rid of Aphids: Fast and Easy
FAQ
What is the fastest way to get rid of aphids?
Will Dawn dish soap kill aphids on plants?
Can you spray vinegar on plants to kill aphids?
A vinegar spray can be an effective natural method for controlling aphids, but it’s crucial to use it with caution to avoid harming your plants. A solution of 1 part vinegar to 3 or 5 parts water is generally recommended. Directly spraying the aphids with this solution can kill them on contact.
Can a plant recover from aphids?
Yes, a plant can bounce back from an aphid infestation and be fine for next year. Just check on it more frequently to make sure you didn’t leave any survivors and take care of them before they have a chance to take over.