Common Garden Pests

Bugs eating your seedlings' leaves? Worried about cucumber beetles? Here's a quick reference guide on some of the most common garden pests. Be sure to send us gardening tips and questions to

Cabbage White Butterflies
  • Off-white in colour, with one or two grayish-black spots per wing
  • Wing span of two inches across
  • Lay their eggs on plants, usually on the underside of the leaves. The eggs are yellow and oval shaped. Clustered.
  • The larvae, cabbage worms, eat through the plants, such as cabbage, broccoli, brussel sprouts, and cauliflower.
  • Velvety green, inch worm type caterpillars
  • Only attack plants in the “brasica” family: Mustard family: Cabbage, Kale, Cauliflower, Broccoli, etc.
  • Leaves need to be checked regularly for the eggs because a serious infestation can kill the plant
  • Check your plants frequently for worms as well
  • Hand pick and destroy them
  • Take big chunks out of the leaves
  • Not always problematic if the plants have matured. BUT if the plants are young, these critters can kill them.
  • To prevent plants from infestation, protect them with floating row covers.
  • Insert into a nylon stocking

Cucumber Beetles
  • Small, quarter inch in length, yellow and black
  •  Carry Mosaic virus that can spread to plants
  • Attack gourds (pumpkins, squash)
  • Lacy effect on the leaves. The virus eats away at the leaf
Cucumber beetles lay their eggs on the undersides of leaves, and when the larvae hatch, they eat the roots of cucumber, melon, and other plants. The larvae grow to be adults around early July, when they begin to feed on foliage and flowers. There can be up to three generations of these beetles each summer. The beetles winter in piles of leaves and other debris.
  • Plant radishes or nasturtiums near plants
  • Straw, hay, grass clipping mulch at the base of the plant so that when cucumber beetles fall they can no longer burrow into the ground...
  • Pick them off
  • Clean your garden
  • Cover up your cucumbers
  • Use insecticides (organic: EcoSMART Garden Insect Killer)
  • Cover cucumbers with cheesecloths, cones, or a commercial row cover.

Flea Beetles
Many flea beetles are attractively coloured; dark, shiny and often metallic colors predominate. Adult flea beetles feed externally on plants, eating the surface of the leaves, stems and petals. Under heavy feeding the small round holes caused by an individual flea beetle's feeding may coalesce into larger areas of damage.
  • They leave tiny holes in leaves
  • They don’t have a uniform appearance (black, brown, green, stripes, spots)
  • Main characteristics: They are small and jump
  • They leave clusters of holes
  • Attack the root systems and make the plants susceptible to other pests
  • Young plants are more susceptible to flea beetles.
  • Difficult to get rid of flea beetles

Preventative measures (pre and post):
  • Thick layer of mulch, inhibit the ability of larvae
  • Weed often (removes food sources for the larvae)

Squash Bug
Squash bugs infest squash and pumpkin plants. Adults like to hide down at the base of the plant or underneath the leaves. These bugs go from eggs to nymphs in seven to 10 days, so you should look for eggs about every seven days to catch them from turning into nymphs. The squash bug PRODUCES ONE NEW GENERATION EACH YEAR but of course if each squash bug lays 15 eggs on each leaf they chose to deposit their eggs on, then all those newly hatched nymphs will lay more-but not this year. The nymphs will grow into adults this year but will not lay eggs. They will overwinter and lay their eggs next year.
How to combat:
  • Look regularly for adults, nymphs, and eggs.
  • Take the hose and spray the whole plant and at particularly at the base which is covered in straw. The adults come running up the stems of the leaves to escape the water. Then pick them off with my hand. You can squish them on the ground or put them in a bucket of soapy water where the adults drown, or relocate to some spot far away.
  • Look at EACH LEAF of the plant to see if there are any EGGS ON THE UNDERNEATH SIDE OF THE LEAVES, usually in the “v” where the veins form. If you find them, either tear off the whole leaf (if you have a lot of leaves) or tear out just the section that has the eggs and put them in a bucket of soapy water where they will smother. THE EGGS WILL BE DARK LIKE ROOTBEER WHEN THEY ARE READY TO HATCH, so get them EARLY.
  • Look for GRAY NYMPHS WHICH ARE USUALLY UNDERNEATH THE LEAVES OR ON THE STEMS. If you find a few, squish them or relocate. If you find a lot, take the whole leaf off because they are fast.
  • The key is to be REALLY DILIGENT ABOUT FINDING THEM BEFORE THE EGGS HATCH. After they hatch you can easily be overcome by the nymphs. Most people don’t keep up on the inspections and then the problem magnifies tenfold-so keep up on them. The hunt is on!
  • Cover your plants with row cover to keep them off. This works beautifully but you may have to piece some row covers together to cover some of the larger plants. I use clothes pins to clip them together.
  • Use Neem. It is an organic pesticide (and an added benefit is a fungicide). It must be sprayed very early before the bees come out or at dusk when they aren’t around as it won’t hurt them if it is not a direct hit as they only visit the flowers and it is a contact spray.
  • Plant a crop late in the season if possible. Many areas of the country only have one generation of squash bugs and if you plant later you may miss them.
  • Onion Spray: You can deter squash bugs on pumpkins, winter squash, summer squash and marrows with diluted/strained onion juice. Evidently just grind one or two up, put it in gallon of water and strain the onions out so your sprayer doesn’t clog.
  • Companion Planting: Plant onions bulbs with your squash every year.


Nicole Caldwell

Nicole Caldwell is a self-taught environmentalist, green-living savant and sustainability educator with more than a decade of professional writing experience. She is also the co-founder of Better Farm and president of betterArts. Nicole’s work has been featured in Mother Earth News, Reader’s Digest, Time Out New York, and many other publications. Her first book, Better: The Everyday Art of Sustainable Living, is due out this July through New Society Publishers.