Cucumber Leaf Damage Identification: How to Identify Pests, & Manage Leaf Hoppers with Peppermint Oil Spray (Recipe)

The first rule is to identify what is harming your plant. Once identified, you now know if your plants are dealing with a virus, fungus, or pest problem. Proper identification leads to selecting the right treatment. Treating pest damage with an antifungal baking soda spray, would be ineffective.

Cucumber plants can be affected by all the above depending on the time of year, weather, and location of the garden. The damage to these leaves is caused by leaf hoppers. They feed on the undersides of the leaves. The damaged leaf, first appears dark green, then yellows, browns, and the leaf begins to die off significantly. They eat with the veins of the plant leaf and create very angular feeding shapes. This angular pattern sometimes fools gardeners into believing it is a fugus or virus.

I always recommended taking notes so you know when problems show up in the garden. They most likely will return the same time every year. Leaf hoppers tend to select taller more mature cucumbers plants but will attack what is available to them. I started my spray routine late this year, as I was away on vacation for 1 week. I prefer using peppermint oil as my main treatment for smaller soft bodied insects. You can spray this mix every 2-3 days for an outbreak over 3 or 4 cycles. It irritates, repels, and kills.

Peppermint Oil Insect Irritant Spray

1-2 tablespoons of pepper mint oil per gallon of water (I recommend 2)
1-3 teaspoons of dish or detergent soap (soaps vary and too much can damage leaves)

I recommend using Castille type soap as it is pure soap and mild. When using Castille pure soaps, I use 1-2 tablespoons per gallon. 

Oil will float on water and you need soap to disperse the oil through the mix. Soap will also kill soft bodied insects. 

Spray the tops and bottoms of the leaves, shaking regularly to keep the oil mixed in the water.

You can also use rosemary oil or a combination of both. You can find these at my seed and garden shop. If you don’t purchase them from me, make sure to purchase pure oil and not an extract. The oil is potent and that is what you want to manage insects.

To maintain healthy plants, spraying every 7-10 days is effective. Even though this spray mix is relatively mild, always test spray new sprays in your garden and wait 24-48 hours to see if they cause leaf damage.

“Good Luck in Your Gardens”
Cheers!

Gary (The Rusted Garden)