Last season’s notes from a gardener’s journal TOMATOES

By JOYCE KARSNAK

OSU Ext. master gardener volunteer

CANFIELD

“Did you mulch?” was the question our Extension Educator Eric Barrett asked last September when I lamented over the browned and shriveled leaves on my tomato plants laden with half-ripened fruit.

They looked more like a heavy freeze had hit them rather than the hot August summer.

The plants went from thriving green to yellow with dark spotting, to drooping, dried up brown within a couple weeks, starting on one plant but spreading quickly to the others in the same patch of ground.

“No, I didn’t mulch this year. I could barely get the plants in from all of the rains,” I replied, feeling rather sheepish to have neglected to use newspaper to line tomato rows, recommended in every class on growing tomatoes along with using a soaker hose, one of the basic rules we learned as master gardeners.

The newspapers covered with a sprinkle of mulch not only controls weeds, but they prevent the splashing of the disease from the soil onto the plant itself.

Early blight

Here is the diagnosis. It is caused by a fungus called Alternaria solani that lurks in the soil. During warm and wet conditions, rainwater splashing up to lower leaves even when staked can infect the plant. It can occur any time during the growing season but usually after fruit is set. That timing is when the temperature is warmest and humid.

Hence, mulching would have helped as a barrier between the tomato leaves and the ground.

Unlike other disorders that can ruin the entire crop, the early blight did not affect fruits. They had begun to ripen, ultimately on the porch picnic table. They hung on the vine for as long as it held, and that is when I found the worm.

Yellow-striped army worm

It burrowed in the tomato. It will eat foliage but will also damage tomatoes and green peppers (found holes there, too). They produce a few generations each season. For details, go to http://go.osu.edu/stripedarmyworm.

Had I been more observant, I could have noticed the worm’s telltale droppings. They tend to hide during the day and feed at night, so for hand eradication, scouting is best done early or late in the day. The worm was the final insult. The tomatoes were dropping from blight and were packed with damage inflicted by the stink bugs.

Stink bug damage

They pierce the tomato, then suck on the fruit. If the damage occurs on green tomatoes, the result is a yellow blotch on the skin of the ripened fruit. Ripe red fruit feeding results in cloudy spots on the skin.

In either case, the result are plugs of white tissue under the peel that needed to be cut away. The culprit was the invasive species brown marmorated stink bug that has lived in Ohio only since 2007. The plugs were easily cut away from the fruit with minimal loss. Bless those tomatoes, they still made the best pizza sauce.

Lessons learned

Rotate tomato plants to a different garden area away from the infected soil. Scout for pests. Put down the soaker hoses and don’t forget to mulch.