Indoor Plant Bugs: How To Defend Against Houseplant Pests

I think it’s silly! The very best articles on guarding against indoor plant bugs and houseplant pests always start by suggesting you buy “clean stock from reputable dealers,” which has always seemed a little weird to me.

No dealer, reputable or otherwise, likes bug-infested plants any better than you or I. So who among us, for heaven’s sake, is going to buy UNclean plants purposely?

house plant bugsPin

Insects can happen to any type of plant, any time, any place, and the old saying “them as has, gits” certainly applies here. Anyone who has planted will, sooner or later, get bugs and their eggs on them.

Properly speaking, bugs are not bugs but are, instead, insects. And according to Noah Webster, the term may refer to any of “numerous” small invertebrate animals.

And numerous these pesky little things are, too; when I think I’ve done battle with all the known species, a new one turns up, and the fray begins again. (The most recent pest to take up residence on my houseplants is oat thrips. And I’m not within 100 miles of an oat field!)

Whether you call them insects or bugs or a name is not fit to print, the chances are that some or all of the arthropods described here have either already had a merry time with your plants or will have in the future.

Healthy plants, given the proper care, are more bug-resistant than sickly plants, so if your indoor garden is in robust shape, you may not need this advice.

I have had very few infestations, given the number of plants I’ve grown and the number of sources I receive plants.

Our Spray Insecticide of Choice

Throughout this article and Plant Care Today, we reference natural organic Neem Oil insecticides.

Neem is our houseplant insecticide of the first choice. You can buy this natural solution at Amazon or at local garden centers. We also like insecticidal soaps.

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But, now and then, a perfectly healthy plant comes down with a bad case of thrips, aphids, or mealybugs. Some insects appear so suddenly, and in such large numbers it almost makes one belief in spontaneous creation!

White Flies

The insect that heads my unpopularity list is the whitefly. Other insects may be annoying or damaging, or both, but this is even more so! Brush by an infested plant, and whisshh… the little things fly off in all directions.

Aim a sprayer at them… ditto. Whiteflies suck plant sap, leave the foliage pale and mottled, are undesirable, and are equally hard to get rid of.

Of course, if you are a “fast draw” with a spray bottle, and can stand on your head to see the undersides of leaves (where the whiteflies rest between flights), then eradication should be no problem for you.

During warm weather, my method is to lift the plant gently and carry it outdoors without disturbing the flies. There I knock them galley-west with a forcible spray from the hose and run back inside with the plant before the bugs can regroup their forces.

If I do this every week for a month, the plant is usually back to normal.

Whiteflies are partial to flowering-maplehiding under coleus leaves, geranium, begonia, fern, Fuchsia plants, and practically any plant you care to mention.

I suggest isolating any infested plant and giving it the works.

  • Outdoors spray with clear or soapy water
  • Indoors with a spray

If the bugs keep multiplying faster than you can kill them, throw the plant away.

Mealybugs The Sneaky Indoor Plant Pests!

The sneakiest houseplant bug and one of the most common plant pests are mealy bugs.

This cottony-looking critter grows up to one-quarter of an inch long, and once it leaves its hiding place in a leaf axil or flower buds, and is easily visible. But, unfortunately, it usually stays in hiding until it (he? she?) has multiplied into a whole horde. Then they suddenly emerge and are all over the place.

Mealybugs suck plant juices and are damaging, besides being fairly repulsive-looking. So get after them right away. I like to lift them off with a small cotton swab dipped in alcohol.

The alcohol seems to penetrate the mealybugs’ waxy coating, and a drop or two poured into crevices the swab can’t get to will make the bugs somewhat sick if it doesn’t kill them outright.

After this treatment, spray the plant with clear water to remove the traces of alcohol.

Scale – A Bug For All Plants!

Scale insects, or scales, if you prefer, are also partial to practically everything, just like whiteflies, but prefer woody-stemmed plants like:

  • Gardenia bushes
  • Garden Croton
  • Citrus plants
  • Ficus bushes and trees
  • Indoor palms
  • Ivy

… and the like.

One eminent writer described these as “motionless, and unable to move from place to place,”… so how come mine progress like crazy along branches and leaves whenever I turn my back?

I’m sure that writer must have meant that adult specimens tend to cling limpet-like in one place; the junior members of the clan practically set speed records one week on my gardenia bush!

Scale insects may grow to one-quarter of an inch in length and are usually dark-colored.

Those that favor my plants are brown or blackish. Sometimes a stream of water will dislodge these if not firmly established, or you can use Neem oil on them. I prefer to mash individual specimens right in their tracks or lift them off with the tip of a knife blade.

To clear up a bad infestation may mean you have to go over the entire plant every morning for a month or more, but handpicking the creatures won’t damage the plant, and it is the surest method I know.

Plant Damage From Mites “Sucking” The Life Out Of A Plant

Maybe your problem is mites? These come in assorted sizes, names, and colors, but very tiny red spider mites are the most common on my potted plants.

It shows up only when the air is too hot and dry for certain house plants, so I suppose the havoc they wreak is my fault. Spider mites cause the undersurfaces of the foliage to look webby and feel gritty, and in no time, they can kill the growing tips or the entire plant.

A Neem oil application has been effective against spider mites and daily spraying with plain water.

Cyclamen mites, evidently misnamed since they thoroughly enjoy a host of plants in addition to cyclamen, cause stunted, deformed growth.

A badly infested plant should, in my opinion, be disposed of, although there are miticides that purport to kill them without plant damage.

Or, if you like your plants par-boiled, you might try dipping them in hot water (above 100° degrees Fahrenheit) for ten or fifteen minutes. This is said to be a fairly sure cure.

Sometimes you can propagate the plant from a healthy cutting and discard the most badly infested part; then use miticide to inhibit the growth of any mites which might be lurking on the cutting.


Thrips, small, rapid, and black or brown, may be suspected of causing trouble if your plants have deformed buds or flowers or if the foliage develops a silvery color.

Sometimes forcible spraying with clear water will dislodge them, and neem insecticide sprays usually put an end to them, but once in a while, I’ve had to resort to the solution of taking a thrip-free cutting and discard the main plant.

Strangely enough, the thrip that is most susceptible to sprays isn’t the one that favors my indoor plants! But, as I said earlier, I’ve got oat-thrips.

My County Agent tells me that the standard pest control used by farmers is not designed for indoor use, so I’ve just had to put up with them, more or less, taking cuttings when the thrips get too plentiful and waiting for cool weather when they disappear.

Aphids – Pesky, Troublesome Soft-Bodied Insects We Call Plant Lice

Aphids are well-known or common pests. Therefore, they probably need no description.

But for the sake of any novice gardeners who have never seen aphids, they are about one-eighth of an inch long, red, gray, green, or black, and stand quite erectly on their skinny little bow-legs.

The favorite dining area of the aphid is the succulent terminal growth of almost any plant. Their juice-sucking activities promptly put the plant on the sick list.

Aphids are most plentiful in the summer when they ride indoors in the breeze (or on your clothes or plants you bring in).

There are several ways of naturally getting rid of aphid pests, but they can be hosed off into the sink or killed easily with malathion or all-natural neem oil spray.


Without a few words on springtails, no article on house plant insects would be complete.

These terrifically active little insect pests jump around excitedly when watering your plants. Sometimes they show up in large numbers in plant-pot saucers or scurrying around on the sides of pots plunged in peat moss.

For all the commotion they make, it would seem logical that they would do an equal amount of damage, but they are harmless.

I don’t care for them, especially when they leap off a plant I’m using as a dining table centerpiece and get on the silverware or inch up the glasses!

But springtails are a natural constituent of rich soil surface, which has a high organic content, and they feed on the decaying vegetable matter, not on the live plant parts. However, try neem oil if you want to get rid of springtails.

Slugs – Lovers Of The Parts Of Your Choicest Plants!

Here’s our favorite control for Slugs and Snails – Diatomaceous earth! Learn about the many uses and benefits of Diatomaceous Earth.

One more pest, not really in the insect classification, however, is the slug. These snails-without-shells always seek out the most prominent parts of your choicest plants for their foraging.

However, during the daylight hours, they love to conceal themselves under the pot-rim, where they are easily found once you suspect their presence (a slimy trail and chewed leaves means slugs).

Just remove and squish in a piece of paper.

Remember, if you follow good cultural practices with your plants, you may never be troubled with any of these garden pests. So use that well-known ounce of prevention… it’s much simpler in the long run than any cure.

by K Walker

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