Critters in your houseplants?

  • Downhome Magazine
  • Posted: Jan 14, 2022 10:58 AM


By Kim Thistle

If you have houseplants, you know just how aggravating it can be to find yourself renting out accommodations to pesky insects. At the first sign of one little creature, you can be sure that tomorrow there will be dozens. Fortunately, there are a few preventative measures that you can take before you get a full-on invasion.

What to watch for

• Before purchasing you should check plants over thoroughly. Not only should you look for insects, but also for signs of insect damage such as honeydew, the sticky excrement of many pests.  

• Once you introduce a plant into your home, it is best to quarantine it in a separate room for a couple of weeks to see if any nasties show up. Often there may be no sign of adults in your new plant, but there could be eggs or larvae that are hard to detect. By keeping the plant in a holding area, it will give time for these eggs to hatch.

• Yellow sticky traps placed just above the plant will attract insects that will stick to the card. If anything untoward shows up, it is a sign that there are many more in the plant that you have not yet detected. These traps are available for purchase at your local garden centre, but you can also make your own at home. All you need is a swatch of yellow cardboard or paper smeared with Vaseline. The insects are attracted to yellow. As soon as they touch the paper they stick to the Vaseline and are unable to free themselves. If you find anything, you should treat the plant before introducing it to the rest of your home. 

• Constant monitoring is a must. Every time you water your plants you should check them over for signs of damage. Often, the damage is noticed before the actual insect. You may see discolouring of the leaf, changes in leaf texture or spot webbing at the intersection of leaf and stem. If honeydew is present, you have a problem. This feels a bit liked spilled lemonade and it drips onto surfaces surrounding the plant. If the honeydew is serious enough it encourages a mould, which looks a bit like soot. 

• Insects multiply rapidly in an indoor environment, so don’t put off treatment when you see signs. Act immediately. Some insects are born pregnant and they give birth to enough young’uns that can make your life miserable.

Common culprits

• Aphids. These are small yellow, green, orange or black six-legged bugs. They are usually seen in clusters around the tips of new growth. Nasty little things they are. These insects are born pregnant and will give birth to as many as 100 nymphs at one time. At the first sign of these, wash them off under running water. Quarantine your plant and be sure to wash it off with a strong jet of water every three days until you have them under control. You can also squish them with your fingers if you are not squeamish, or use rubbing alcohol on a Q-tip to remove them. Insecticidal soap works wonders and is safe to use.

• Spider mite. These tiny arachnids are usually prolific under hot, dry conditions. You will probably not see the spider as it is very, very tiny, but there are telltale signs. The leaves of your plant will look pale and lose their sheen. Upon close examination, you will see very fine webbing on the undersides of the leaves or at the leaf axil. Spiders are wind surfers and float around on drag lines, so chances are that if one plant has them, someone has escaped and begun reproduction on a neighbouring plant.

Prevention is key here. Keep your plants hydrated and do not let them dry out. Make sure you are using a healthy soil with organic matter, such as worm castings; healthy soil creates healthy plants that are better able to fight off problems. As soon as you see any sign of this pest, quarantine it and, again, spray with a hard jet of water. Remove as much of the webbing as you can as this is what is used to protect their eggs. Horticultural oil or dormant oil is a great organic treatment after you have done your initial cleaning. If you can find a hungry ladybug, introduce her to your plant and she will clean up the remaining spider mites.

• Whitefly. Hideous creatures, they look like tiny white moths that become airborne when a plant is moved. These insects are also producers of honeydew that increases the chance of fungal diseases on your plants. As with any insect problem, it is important to keep your plant healthy. Do not let it become stressed from being pot bound or improperly hydrated. If you spot an infestation, get the vacuum out. You can destroy a goodly number of these bugs by sucking them up gently with your vacuum nozzle. Be careful not to injure your plant in the process. Remove the bag afterward and get it out of the house. Once this step is completed you can spray with insecticidal soap.

Prevention tips

It is key to be diligent when it comes to houseplants. A few preventative measures may keep pests at bay.  

• Repot your plant as soon as you bring it into your home. Use a good quality, sterile soil with organic matter already added, or add your own. I love worm castings.

• Avoid repotting to a significantly larger container. Rather, go up one size in diameter.  

• Use an organic fertilizer.

• Stick to a healthy watering schedule.  

• Clean your plants regularly with a damp cloth. A layer of dust will prevent them from transpiring properly and may hide insect eggs.

Houseplants are a wonderful addition to any household, but like any living thing, they require maintenance. Be diligent with your monitoring. An ounce of prevention is worth a pound of cure.