Dakota Gardener: Battling bugs in the garden

Gardens in North Dakota look great this year. The rains have been plentiful in most areas, and our plants are thriving.

Be prepared to protect your garden from insect pests. Swarms of flea beetles will be arriving soon, and I see white moths laying eggs on my cabbage today.

Whenever my vegetable garden gets attacked by insect pests, I don't get sad.

Instead, I get mad. Then I get even.

When I was a farm boy, I sprayed a product called Sevin (perhaps misspelled but very effective) to kill the pests. The bugs dropped to the ground and died. Revenge felt sweet!

Synthetic pyrethroids are widely available at garden centers today. These chemicals kill many insects quickly and protect our crops for several days. Products include zeta-cypermethrin (GardenTech Sevin), permethrin (Bonide Eight) and cyfluthrin (Bio Advanced Vegetable and Garden Insect Spray).

The ultimate foe in Dakota gardens is the hornworm. These giant caterpillars destroy gardens by eating four times their weight every day. Imagine! These "garden gluttons" increase in size 1,000-fold in 30 days. That is like a cat turning into an elephant in a month!

When I see hornworms on my tomato vines, I don't use Sevin or Eight insecticides. I use my favorite natural insecticide. I call it "Thirteen," which is the size of my shoe. I pick off the hornworms and step on them.

Besides my shoes, there are lots of natural insecticides available today. In general, these chemicals are safer for us and persist for a shorter time in the environment compared to synthetic chemicals. That's good.

Spinosad has emerged as one of the most popular and effective organic insecticides. It was discovered when a chemist on vacation in the Caribbean stumbled by a rum distillery and noticed there were very few pests around. He discovered the pesticide in the soil. Spinosad kills a wide range of insects and mites.

Bacillus thuringiensis is another great weapon. Almost harmless to humans, this bacterium causes a gut rot in caterpillars. The caterpillars eat the bacterium and then die. Kurstaki, the most common strain of this insecticide (trade names Dipel and Thuricide), only kills caterpillars. It won't harm beneficial insects such as ladybugs and bees. I enjoy killing my foes in battle while not harming my friends.

Neem oil comes from the seeds of the neem tree. Neem initially acts as a feeding repellent. Bugs exposed to neem will lose their appetite and then suffer hormonal problems. They fail to mature, fail to reproduce, and slowly wither away.

Pyrethrin is another weapon available in our war chest. This organic chemical comes from chrysanthemums. Pyrethrin kills pests immediately and then breaks down in sunlight after only a day or two. It's a precise killer with no long-term effects in the garden.

As you can see, we have lots of insecticides available to protect our harvest. Choose your weapon wisely and let's get ready to rumble!

For more information about gardening, contact your local NDSU Extension agent. Find the Extension office for your county at ndsu.ag/countyoffice.