Mother Nature asserts herself in every garden: weeds, insects, disease ... they’re all waiting to take control, and although you can’t stop her, the first step in combating her is recognizing the signs and vigilantly watching for them. Here’s a primer.
Dropping a hint: The first signs of a tomato hornworm's chewing damage are their droppings, which are easier to see than the green caterpillars themselves. The caterpillars normally start eating at the tops of plants. Pick them off and destroy them.
But, if the hornworm is has tiny white "Tic-Tac" shaped parasites hanging off its body, leave it alone. This Braconid parasite is a beneficial and important factor in hornworm control.
Late fruiters: Assuming you did not give the plant too much Nitrogen, lack of bearing fruit may be weather-related: nighttime temperatures that remain above 70 degrees or below 50 interfere with pollination. Fruit set can also be hampered by irregular watering.
Rot Bottom: Blossom-end rot, so called because the bottom is where the flower was before the fruit began to grow, can appear as leathery and sunken, or be watery-looking. The end is discolored, and dark. The cause: not enough calcium, caused by water stress. Some gardeners work lime or calcium into the beds as a preventive measure.
Greenbacks: On a tomato’s stem end, having a “greenback” doesn’t signal a bumper crop, it means the area remains hard, green and unripened. Too much sunshine can sometimes be the culprit.
Seeing Spots: Various fungal diseases, cankers, viruses and bacterial conditions can show up as spots on tomato skin. If your tomatoes get anthracnose (sunken round spots that go dark in the middle for a bull’s-eye effect), alternaria canker (a.k.a. blight, sunken gray-brown marks on fruit, accompanied by plant lesions), or black mold and ghost spot (watery spots with dark centers), crop rotation might have helped prevent it, and is a must next year.
Tomato foliage can also experience all manner of spotting, and many such afflictions are symptoms of the same cankers, blights, fungi and viruses.
Sometimes leaves fall off from the bottom up, other times it’s from the top-down. Bacterial wilt is a top-down deal, while fusarium and verticillium begin at the bottom of the plant. Apply two inches of compost, then mulch lightly. A barrier of clean mulch applied at planting time can reduce some spores that splash up from the soil onto plants.
False start: Sometimes tomatoes set fruit, and then drop it when it’s barely the size of a small bead. Hot, dry conditions at blossom time (90 degrees plus) prevents proper pollination and causes buds or tiny fruit to drop. If it’s early enough, hopefully a next round of flowers appears during more favorable weather. Some gardeners hose down their plants if the weather is inhospitable, hoping to encourage fruit set.
Cracking up: Cracks often develop when moisture suddenly becomes abundant after not enough and the fruit swells faster than the skin can expand. Too much Nitrogen can also bring on cracking, as can some fungal diseases and even plant genetics (large-fruited beefsteak types are said to be more susceptible).
Bring any and all gardening questions to us at Gateway, we love tomatoes and want you to have a bumper crop.
