Dealing With Common Garden Pests

Gardening season is in full swing and I am busy keeping things weeded, watered and free of pests. Here are some of the most common pests you’ll deal with here in the Northwest and how you can minimize them in your garden. 

  • Avoid watering foliage when watering your plants, if possible. Water at the base. 
  • Throw away leaves that are damaged, diseased, or pest-ridden.
  • Inspect your plants often. Notice changes in coloration, firmness, number, and any damage. Look at the underside of leaves for eggs, insects, or other warning signs.

Cabbage Worm
Cabbage Worms are the larval stage of those pretty white moths you might see fluttering around the garden. They effect brassicas such as cabbage, cauliflower, and broccoli. They will start with the leaves and move in to the heads if left unchecked. 

Common Garden Pests
What a nice, big hole in my broccoli leaf.
Common Garden Pests
This is the caterpillar I picked off, playing dead. Nice try.
  • You can use row covers to cover your whole garden and prevent flying insects from accessing it.
  • If you see small holes forming in the leaves, check underneath for worms. They can be a few milimeters to a few inches long and are often along the veins. Pick them off! 
  • Also look for small, green, protruding eggs that can be rubbed off
Aphids are small, usually black, soft bodied insects that suck the sap from the stems and leaves of plants to weaken them. They reproduce rapidly and can take over a plant as well as spread diseases between plants. It’s lovely.


  • Introduce predatory bugs like ladybugs. You can buy them from a local nursery or order them online.
  • Wipe them off with hand or soft cloth, or spray off with a hose.
  • Grow trap crops like marigolds or nasturtiums. They will attract the aphids away from your vegetables.
  • Use homemade sprays, but sparingly because they can harm beneficial insects if used too often. Also use these in the morning before the full direct sun hits.
    • Tomato Leaf Spray: Soak two cups of chopped up tomato leaves in two cups of water overnight. Strain out the leaves and add two more cups of water. Pour into a spray bottle. 


Slugs in the Northwest are very destructive. They’ve already eaten three entire basil plants in my garden this year. I hate them. Moving on.

Slugs like wet soil and foliage. They eat any leaves on or close to the ground. One approach is surrounding a raised garden bed with rough gravel that slugs will find prohibitive. But if that’s not an option, there are several other ways to deal with them.  


  • Pine Needles in a layer all around the plants. This is my best solution so far! Even when the pine needles are wet, slugs will not cross them.
  • Water in the morning instead of at night. The excess moisture attracts slugs and they are more active at night. 
  • Use copper tape to outline your garden. The slugs will keep out! 
  • Sluggo. It’s not organic and people go back and forth on whether some of its ingredients are too toxic for organic gardening. But here in the Northwest, we are fighting an epic slug battle some years because of the rain. So most organic shops sell it! I use it and love it. 
  • Other barriers: crushed egg shells, nut shells, coffee grounds, etc as a garden perimeter have been used with minimal success. But they may be worth a shot if you have them on hand anyway!
  • Slug traps: Squeezed out orange or grapefruit halves will attract them. Just toss in the morning! Shallow cups of beer are irresistible to slugs, the lushes, and they will climb in and drown themselves. Muahahahaha!
Common Garden Pests
See the little row of white eggs?
Common Garden Pests
The leaves look like there is a water/sun issue.
But it’s larvae. Ewwww!

Leaf Miner

Cool season crops such as spinach, chard and kale suffer the most damage from leaf miners, although they are sometimes seen on tomato and other leaves.
The flies are smaller than a housefly and lay white rows of eggs on the undersides of leaves. When they hatch, the larvae dig in at eat between the layers of the leaf tissue. Then their biceps pop out and they talk like a sailor. Ok not really. 

Damage looks like part of the leaf is papery thin and wilting. You often see the small dark spots indicating larvae between the layers. 


  • Check the underside of healthy leaves to find and remove eggs by rubbing them off. 
  • Remove and throw away all leaves visibly damaged by leaf miners (DO NOT COMPOST THEM)
  • in severe cases, pull up the plants and rotate in a different crop (radishes, carrots, etc.)
  • You can use row covers to cover your whole garden and prevent flying insects from accessing it. 
  • In the fall, turn in and cultivate the soil to disrupt larvae in the ground. 

References and Resources 

What garden pest problems are you facing this year? Any other tips you’d share with us?


This Post Has 7 Comments

  1. srichards

    Thank you so much – tomato leaf spray, who knew?!!?

  2. Right now I’m dealing with a worm that looks very similar to the little green one you show in your picture. It (they) are eating my lettuce. I have been hand picking, but they seem to explode in population every night! I guess I’m going to resort to a spray or there won’t be any lettuce left. I found an organic spray at Home Depot that is made with herbs like rosemary and garlic. We’ll see if this works.

  3. Anonymous

    What causes my gorgeous zucchini plants that just begin to produce to completely collapse and die?? I ti so frustrating to have them be so big and have so many blossoms to see it withered to the ground one morning!

    1. Tauna M

      That sounds like squash vine borers. The larvae bore into stems near the base and dessimate the plant. The moths are black with orange/red spots. Do a search for them for ideas on prevention. I’d probably try a row cover on young plans to prevent eggs from being laid and then remove them when the flowers open. Sorry that happened to you! That would be so frustrating!

  4. Anonymous

    Cut worms are ruining my hard work!!!

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.