Friday, January 6, 2012

Bug Off

Unfortunately, the severity of the winter season does not have that much of an effect on houseplant pests. On the contrary, a variety of insects that attack houseplants flourish in the favourable environment of an insulated, heated home that generates dry and stale air.

Seeing that the winter is not going to keep houseplant pests at bay, you’ll have to take matters into your own hands if you discover an outbreak on a cherished plant. And those ‘matters’ consist of popular, non-commercial methods of control that I’ve listed below.

Bug Off – Dealing With Houseplant Pests

No houseplant is immune to infestations; they are all – to some degree - susceptible to attacks by an assortment of insects and pests. Some infestations are just an unsightly nuisance while others can cause considerable damage to a plant, even its untimely death. How you deal with unfortunate invasions depends on the infected plant, the pest involved and the magnitude of the problem.

Here are a few ways to get those pests to bug off:

Practice Prevention

Pests spread from one plant to another by hitching a ride on your hands, clothes, gardening tools, dusters and anything else that comes into contact with them. They are also transported from one location to another by air currents. But more often than not, they go home with you on a plant that you picked up at the greenhouse; a plant that was already plagued by bugs. That’s why it’s important to inspect purchases thoroughly to avoid future problems. Buy only healthy specimens, isolate new plants from your existing stock for at least two weeks (preferably a month) and practice prevention methods to keep problems at bay.

Catch Pests In The Early Stages

Plants give clear signs if something is ailing them – by means of symptoms – so peek in on them from time to time to check on their progress. This will reveal the emergence of problems – pests included - in their early stages, way before they spiral out of control, giving you the opportunity to nip them in the bud and restore your plant’s health quickly and efficiently. Take a close look at your plants every time you water them. Inspect their leaves, stems, growing medium and surrounding area for signs of trouble. Observation is the best method of control.

Isolate Infested Plants

If you discover bugs on a plant, move it as far away from the rest of your greenery as possible. Isolation will help curb any further infestations, especially by insects that are very invasive. If you are treating multiple plants, keep them separated. You don’t want to cure one from its problems only to have it contaminated all over again by pests residing on its neighbour. Remember to wash your hands thoroughly after handling an infected plant; they are often the reason insects spread to neighbouring greenery. Do not place an infected plant back in its usual spot until there are no more signs of pests.

Pick Them Up, Pick Them Off

Houseplants that spend the warmer months outdoors may occasionally be invaded by insects such as beetles, grasshoppers, caterpillars, worms, earwigs, and so on. Even plants kept indoors all year round have the potential to be visited by these outdoor pests that wander inside through open windows and doors. Handpicking these large, clearly-visible critters is a much easier and more effective method of control. If you are queasy about this method, sport a pair of gardening gloves, use a pair of tweezers, or just ask someone to do it for you.

Spray And Wash

Some insects are not very good at hanging onto their host plants, so knock a few off by cleaning the plant. Start with forcefully removing as many pests as possible by spraying infested plants with a strong burst of water in the shower or with the garden hose outdoors - if the weather permits. This manual method of removal washes away many pests, and also kills quite a few in the process. Repeat the process often over the next several days and weeks to deal with future generations that have not hatched yet.

After you have knocked off a few demons, give your plant a thorough wash. Small plants can be rinsed under the kitchen sink or in your shower. Larger plants can be washed with a sponge or soft cloth. Stroke the leaves from top to bottom, making sure to work through the entire plant. Place added effort on cleaning stems, leaf axils and the undersides of leaves. For added insurance, wash your plant every 5 – 7 days with a soapy solution (1 – 2 tablespoons of mild dish soap per gallon of water) for three to four weeks. Use warm water, and rinse thoroughly to remove all traces of soap after you are done.

Set Up Sticky Traps

Whiteflies, aphids, thrips, fungus gnats and various flying insects can be controlled with yellow sticky traps. The colour yellow attracts them and the sticky coating traps them, reducing their numbers significantly. Adults that are captured cannot lay eggs; this helps break the life cycle. Bear in mind that sticky traps alone cannot eliminate an entire infestation, especially a severe one, and are best used together with other treatments. Yellow sticky traps are sold commercially but you can also make them yourself with bright yellow paper and an appropriate adhesive. A search on the internet with provide you with oodles of suggestions on how to make these traps.

Dip Pot And Plant In Hot Water

This form of treatment is usually recommended for African Violets and other Gesneriads but can be used for any plant infested with cyclamen mites. Start by trimming away severely injured plant parts and then immerse the infested plant, pot and all, in hot water at a temperature of 43ºC (110ºF) for a minimum of 15 minutes, maximum of 30. Success of this treatment depends on control of the water temperature; add warm water as needed to maintain the level at a constant 43ºC (110ºF). If performed correctly, the hot water immersion can stamp out all stages of cyclamen mites.

Dunk The Foliage In Plain (Or Soapy) Water

For smaller plants, place aluminum foil or plastic wrap over the soil, support the plant and its medium by placing your fingers over the base of the plant (soil level), turn it upside down, dunk the foliage in a bucket of water and swish the leaves back and forth. You can add ½ teaspoon of mild dish soap to each liter of water for extra cleaning power or insecticidal soap to guarantee that there’s no leaf burn. Never use soaps that contain degreasing compounds that may damage the leaves of delicate plants.

For houseplants grown in the hydroculture system, fill the sink with water, add some mild soap if desired, disassemble the plant setup and immerse the whole kit and caboodle, minus the pellets, in the soapy solution for about 15 minutes. Rinse well and reassemble. As an added precaution, sterilize your clay pellets in a mild bleach solution - 1/2 cup per gallon of water. Make sure to rinse well. You can also sterilize by adding the pellets to a pot of water on the stovetop and boiling them on medium heat for 5 – 10 minutes.

Force Soil Pests To The Surface

Certain pests such as millipedes, centipedes and even earwigs can be driven out of the soil and disposed of. Plunge the infested plant in plain water up to the rim of its pot and let it soak for 20 – 30 minutes. As the soil soaks up water, the pests will surface to the top of the soil in search of air. Dispose by handpicking.

Stock Up On Rubbing Alcohol

Insects such as mealybug and scale are much harder to eradicate because of protective coatings and shells that are basically waterproof. Alcohol strips away those barriers and dehydrates the insect. There are a couple of popular ways to administer this type of application:

Cotton Swabs: Dip a cotton swab in alcohol, touch each insect with it and then wipe it away. Repeat this process until you can no longer see any signs of pests. (Note: This is an easy application for smaller, large-leaved or lightly-infested plants but it is much too tedious for bigger specimens and severe infestations. For the bigger jobs, skip the cotton balls and head straight for the spray bottle, or carry out both methods back to back.)

Spray Bottle: After – or instead of - the cotton swabs, fill up an inexpensive spray bottle with one part (70% isopropyl) rubbing alcohol to three parts water. Spray the infected plant thoroughly, paying particular attention to the nooks and crannies where pests take refuge. For the extermination to be successful, the alcohol mix must make direct contact, so spray away till the plant is absolutely drenched. Repeat this treatment every 3 – 4 days for several weeks to make sure no juveniles get away. Keep the plant out of the sun during treatments.

Create A Sauna To Raise Humidity

For pests such as spider mites that thrive in dry air, slow down the population growth while the infected plant is being treated by creating a sauna effect. Water the plant well, spray it with the preferred treatment and cover it with a clear plastic bag. Secure the cover tightly around the pot and let it stand for several days, until the next treatment application. The bag does not kill the pests; it increases humidity to very high levels, which in turn gives you a better chance at successfully eliminating an infestation by slowing down the pest’s reproductive cycle.

This handy technique is especially useful for larger plants that are too big to lug into the bathtub for a shower or outdoors for a power wash. If you are having trouble getting sizeable plastic bags for larger plants, consider visiting your local dry cleaner and inquiring about a contribution. There’s no harm in asking.

Remember to check your plant daily for signs of mold if humidity is too high. Open up the bag for about an hour each day to allow fresh air to circulate.

One Potato, Two Potato

If you’re not someone like me who gets the hebbie-jeebies when dealing with worm-like critters, try this suggestion, which is especially effective in removing larvae in the soil before they develop into perpetually annoying fungus gnats.

Potato slices, which are attractive to the larval stages of fungus brats, can be placed on the surface of potting soil. The young pests will congregate on and under the slices. Discard the potato pieces when they are heavily populated by the worms.

Warning! This method is not for the faint of heart.

Prune Away

Prune and discard portions of your plant – leaves, stems or fronds - that are heavily infested. The amount and type of pruning is dependent on the plant in question. Before cutting off parts of your plant, learn more about its pruning preferences and what the results may be from such an action. Plants with excellent regenerative abilities can be cut back severely with no ill effects; others may be permanently disfigured by it. Caution is advised.

Tobacco Tea

In one of my houseplant books, I have read about a concoction involving tobacco that is recommended for treating infestations. I’ve never applied this treatment personally to any of my plants, but for what it’s worth, I will list it for my readers who may want to give it a try.

Place a handful (one 3-ounce bag) of regular chewing tobacco in an old nylon stocking and steep it in a gallon of hot water for several days; the mixture will be dark brown. Dip cotton swabs in the tea and dab the insects with it. Or fill up a spray bottle with the mixture, add a few drops of dishwashing liquid to help the mixture stick better and spray infested plants, paying particular attention to leaf axils and the underside of leaves.

There are many recipes for tobacco tea available online, so shop around.

Unusual Homemade Remedies

Here are a couple of mixtures recommended by seasoned houseplant growers as effective prevention measures against soft-bodied pests such as aphids, spider mites and thrips.

Soak a wedge of lemon and a clove of garlic overnight in enough water to fill your plastic mister (12 – 16 ounces). Remove the lemon and garlic. Add 2 – 4 drops of mild dish soap. Fill your mister with this solution. Shake well and spray your plant with it 3 – 4 times a week until the insects are eliminated.

Mince onions and garlic, cover them with enough water to fill a spray mister and let them sit for several hours, preferably overnight. Strain the solution, pour it into a spray bottle and mist plants two to three times a week.

Discard Severely Infested Plants

Determining whether it’s worth the effort to wage war against a particular pest is dependent on the magnitude of the invasion. Small outbursts can be dealt with, and usually eliminated. But what about those dreadfully sizeable ones? Is it worth your while? In my opinion, if the plant is easily replaceable and holds no significant sentimental or monetary value, toss it and pick up another one. This will prevent pests from possibly sweeping through your entire collection of plants and causing a major epidemic in your home.

(Above are just a handful of home-produced remedies to tackle pest infestations. Although there are many commercial products available that are very effective – neem oil, insecticidal soap – there are enough of them to warrant a separate article, which I’ll work on in the future.)

Persistence is the name of the game with infestations. If you are diligent, treat the plant several times with the appropriate remedy and check it regularly for signs of trouble, you can win almost any war.

But more importantly, keep your plants in tiptop shape by watering them properly and providing them with adequate light and humidity. A healthy plant will utilize its own resources to defend itself against infestations while a plant under stress is much more vulnerable to them. By improving cultural practices and maintaining the right environment for your plants, you’ll be one step ahead in controlling pests.

No comments:

Post a Comment