Aphids on Indoor Plants: How to Control Garden Pests Inside

If you’ve gardened indoors for very long, you may have experienced it.

That sinking sensation in your gut — followed by a hint of panic — that comes when you notice something on your plants: bugs.

Ick.

When it comes to indoor garden pests, the most typical culprits are aphids, whiteflies, and spider mites. In this post, you’ll learn about aphids (and how to control them, of course).

What Are Aphids?

A common garden pest, the aphid attacks everything from greens to melons, and it comes in a whopping 4,000 varieties.

But the few species you might encounter indoors tend to look quite similar: pear-shaped, about 1/4 inch long, and a shade of green.

Female aphids can birth live young at the rate of 3–6 little baby aphids per day — without the help of males.

In other words, they literally multiply overnight.

This population surge is especially pronounced indoors because natural forces of control, such as predatory insects and hard freezes, aren’t present.

Signs of an Aphid Infestation

The most obvious sign that you have aphids is the presence of, well, aphids. But their size and color can make them hard to spot — especially in small numbers.

Another telltale sign is the damage that aphids cause.

Aphids feed on plant sap. (They seem to have a hankering for young plant growth in particular.) This stunts and disfigures plants and can even introduce crop-killing viruses.

As if that weren’t enough, aphids also excrete honeydew — a sticky, shiny substance. Honeydew encourages the growth of mold and fungus, which can interrupt photosynthesis and cause other problems.

How Do Aphids Get Inside?

Growing indoors is an effective way to lower the likelihood of aphids. But no environment is completely immune to them.

If you bring in an outside plant, it may already be harboring the pest. Some aphids fly, so they could drift through an open window with the wind. Or they might simply hitch a ride in on your clothes or the dog.

In short, aphids sometimes find their way inside. But you can do something about it if that happens.

3 Ways to Prevent Aphids Indoors

As with any garden problem, the best defense is prevention. (If you already have an aphid infestation, don’t worry — I’ve got treatment tips coming up next.)

To improve your chances of growing a successful indoor garden, follow these three steps.

1. Start seedlings indoors.

As I mentioned, if you bring outside plants inside, you might simultaneously introduce pests. My personal rule is to never use outdoor transplants — even if the plants look healthy and show no signs of pests.

It’s just not worth the risk.

The safest approach is to start all the plants for your indoor garden from seed. It’s a little more work, but at least you’ll know your garden has a fresh, pest-free start.

2. Grow healthy plants.

Unhealthy plants are more vulnerable to pests and diseases. So make sure you’re providing enough nutrients and light.

The Mineral Blend ratio for mature plants is 20mL of A + 20mL of B per gallon of water. But if all your plants are in the seedling stage, a diluted formula is best — 10mL of A + 10mL of B per gallon of water.

Using the Tower Garden Grow Lights Kit? Run your lights for at least 14 hours per day to promote healthy plant growth.

3. Plant aphid-repelling crops.

One of the easiest natural ways to prevent pests (indoors or out) is to grow plants they don’t like. And many herbs — including mint, catnip, chives, dill, and cilantro — actually repel aphids.

Try growing a few of these to keep the bugs at bay.

How to Control Aphids on Indoor Plants

In the event that prevention isn’t enough, it is possible to treat an indoor aphid problem. The key is to catch it early by inspecting your garden as often as daily.

If you notice the signs of trouble outlined above, immediately try one of the following solutions.

Note: Depending on the severity of the infestation, it may be more practical to start over rather than attempt to treat the problem. (Sorry, I know this is something no gardener likes to hear.) If you find aphids on more than one third of your plants, consider cleaning out your growing system and starting new seeds.

1. Remove aphids manually.

For minor infestations, the simplest method of control is to manually remove the aphids.

You can handpick them, prune and destroy infected plant material, or — my favorite technique — press Scotch® tape against infected plant material and then peel it off (with the aphids attached).

2. Wash away aphids.

If the affected plants are small and you’re able to remove them from your Tower Garden, pull them out and run them under a heavy stream of water from a faucet. Alternatively, take your plants outside and spray them with water from a hose.

Aphids aren’t too tough. Often a strong jet of water is all that’s required to flush them away.

3. Spray aphids with natural solutions.

A spray treatment is the most aggressive approach. It’s also the trickiest indoors, as it can be a little messy.

First, you’ll need to prepare the solution. There are two recipes I recommend for indoor aphids. Both are organic-approved.

  • Neem oil + insecticidal soap. Combine one tablespoon of insecticidal soap, one tablespoon of neem oil, and one gallon of water. You can find neem oil and insecticidal soap at most garden stores and online.
  • Essential oils. Per gallon of water, use no more than 10 drops each of peppermint, thyme, rosemary, and clove essential oils.

Pour whichever solution you choose into a spray bottle and apply it to your plants. Take care to coat the undersides of plant leaves — where aphids (and eggs) hide in clusters. These solutions will kill only the aphids they come into direct contact with.

If you’re worried about overspray in your house, mix the solution in a bucket and dip your plants (provided you are able to remove them from your Tower Garden).

What about Good Bugs?

When you have an infestation outside, you can introduce or attract good bugs — known as predatory insects — to help with pest control. Lady beetles and larvae, for example, have voracious appetites for aphids.

But most folks don’t want more bugs running around inside. So I don’t recommend that approach for indoor gardens.

Questions?

Whether you’re new to indoor gardening or have been growing food in your living room for several seasons now, I hope this advice helps you prevent and — worst case — treat aphid problems.

If you have questions about what we’ve covered here, please drop me a comment below!

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