Managing Tomato Pests: Let the Combat Begin

For this gardener, the physical act of gardening, within moments relinquishes burden of daily life and its challenges; a hectic schedule, pursuing a career, managing a farm and ‘juggling’ cumbersome people (not literally-though the thought has crossed my mind). Gardening for me is an outlet & provides me with the ability to transcend the uniformity of modern life, providing an easily accessible escape route (a personal reset). Gardening satisfies a primal urge and allows me to become ‘present in the moment’, using all my senses. The sights, sounds but most importantly to me the smell of warm-moist earth (or soil) is an intoxicating elixir dissolving life’s transgressions providing me regeneration and for a but a moment, the memories of a childhood in Germany with Oma and Opa.

As gardeners, we typically have diverse gardening interests, flower beds & hanging baskets to vegetable gardens and more nuanced specialty plants, like exotic’s requiring highly focused, specific care. Our fascination is with plant growth cycles, nurturing them while watching them grow, it’s the ‘process’ of gardening which we find alluring! I’m certain the flower and vegetable gardens you planted recently look fantastic! Everything is performing well in your personal plant paradise, but then you notice something a bit off in the tomato patch. Some of the tomato leaves appear yellow, or a few of the fruits have blemishes or holes in them, and small insects abound or debris on leaves. What is a gardener to do?

In my humble opinion, home grown tomatoes are the most wonderful gift a gardener can receive from their garden, since the fruit has an incredible flavor straight off the plant-when all goes to plan! But there are numerous hurdles (pests) a gardener must combat before enjoying the fruit. So, while there are many pests, let’s review the top 10 tomato pests for our locale and how to manage them.

• Nematodes are by far the most problematic tomato pests and there are tens of thousands of the species, with the root-knot nematode creating the most havoc. This nematode prevents the plant from getting nutrients from the soil by making galls and a knobby root system. Typically plant discoloration is the first sign of nematode infestation. Note there are many ‘beneficial’ nematodes which play an important role in controlling garden pests, so the best defense against root-knot nematodes is through crop rotation and/or selecting nematode resistant tomato varieties.

• Cutworms are caterpillars which chew through tomato (including numerous other nightshade and basilica plant) stems. They are extremely aggressive larvae requiring little time to decimate newly planted tomatoes. Beige in color, they can be located anywhere on the plant, though normally at the soil surface. This gardener wraps the base of each tomato plant with a thin, 1-inch strip of aluminum foil as a deterrent which has never failed.

• Aphids are sap-sucking insects that affect tomatoes, though a few aphids are harmless. Aphids find strength in numbers, so having a large aphid population will inhibit tomato growth and fruiting. Check the undersides of the plants’ leaves regularly for small green, or black insects, and remove the affected leaves.

• Fruit worms are pale-yellow moth larvae and burrow tiny holes into the fruit. Check the plants’ leaves for small white eggs and remove the affected leaves as they can go undetected until your tomatoes begin to rot.

• Hornworms are very large, green caterpillars with voracious appetites that are perfectly camouflaged by the tomato plants’ green foliage. They leave dropping trails (poop) on plant leaves and are easily removed by plucking from the plant and destroying.

• Leaf-Footed Bugs include stink bugs & squash bugs and are extremely common and the arch nemesis of gardeners. They enjoy hot, humid weather conditions and enjoy the SETX environment! Numerous species look similar in appearance with green or brown hues and are under an inch in length. They carry viruses and affect fruit quality by deforming immature fruit. Speaking from personal experience, planting companion plants such as basil, garlic, rosemary, and others aid in reducing the ‘stink bug’ population, followed by then pluck and squish method to remove the remaining insects as they are located.

• Psyllids are plant lice which jump from plant to plant quickly and are sap-sucking insects which inflict considerable damage to tomato plants. Psyllid saliva is toxic to tomato plants creating “psyllid yellows”, causing foliage to yellow and fall off the plant. Eradication occurs most often naturally by having a cold winter since they cannot survive harsh conditions.

• Beetles there are multiple species of beetles that can threaten tomatoes. Make a habit of thoroughly inspecting tomato plants. Beetles have a variety of appearances, such as Blister beetles are black with red heads, Colorado potato beetles have alternating black and yellow stripes, and flea beetles are solid black entirely. There’s no simple solution to eliminate beetles, as each type of beetle responds to different methods, so research the specific type of beetle and always wear gloves before handling them!

• Thrips are very tiny, narrow insects with four wings but unlike other tomato pests, cause damage through transmission of the tomato wilt virus they carry. Their telltale sign is trails of brown spots on tomato leaves. It’s best to remove infected plants and infested foliage.

• Whiteflies are small, sap-sucking insects, that carry viruses, spreading from plant to plant. They are easily spotted against a red tomato or green foliage and simply treated by removing infected foliage.

So long for now fellow gardeners, let’s go out and grow ourselves a greener, more sustainable world, one plant at a time! If you have gardening questions, email me: [email protected] or phone the Orange County Master Gardeners Helpline: (409) 882-7010.