Tomato Patch: Setback or Disaster?

Typical curled leaf

Sickly—that's the word. Thirteen of my 23 tomato plants look sick, very sick. Is this a disaster—or just a setback?

I set out my plants on May 30, and they seemed to flourish. I mulched and caged them and watered them regularly. Within a week of when I transplanted, our paving guy came to repair several cracks in our driveway and to apply a petroleum-based sealant. Fumes from the sealant were strong, so strong I opened the garage doors for two or three days to air it out. And then came those record-breaking days—99° and 100° F., or were they higher? Leaves of my 13 plants nearest the driveway began to curl, stems to twist, young leaves to shrivel, blossoms to droop.

Most affected were plants near the asphalt—Super San Marzano, Big Mama, Defiant, Virginia Sweets, Juliet, Sungold, and Wow! But two adjacent rows grew normally—three Brandywine (Sudduth’s) and three Brandywine Red, and just 25 feet downhill in another patch, a Virginia Sweets and three Yellow Plum plants flourished.

What’s going on here? I can’t recall reading an article in a gardening magazine about such trauma.

Did the plants wilt in the fumes of the petroleum asphalt sealant? Did the horrendous heat wilt the plants before they became well rooted in the garden soil? Did the heat and fumes combine to injure the plants? Or something else?

I researched on online. I used the index and found relevant information in the University of Maryland Master Gardener Handbook. I went online and submitted a question to the consultants at the University of Maryland Extension’s Home & Garden Information Center.

The consensus is that there are multiple possible causes, so it’s difficult to pinpoint the cause with certainty. Because the leaves curl up, rather than down, herbicide (such as drifting 2,4-D) is not the answer. The most likely suspect is the effect the extreme heat we had last week had on the newly set-out plants. The sealant fumes are hard to factor in because they’re not a common cause of such problems, but in my case, plants between the asphalt and the tomatoes were not affected—peonies, daylily, spotted mint, allium, crape myrtle, butterfly weed, and Shasta daisy.

What am I going to do? I’m going to monitor my sick plants closely. HGIC asked that I report if the situation gets worse.

While I was mulling over possible causes of my sickly tomato plants, I had another troubling thought. Tomatoes—peppers too—have maximum fruit set between 65° and 80° F. They have reduced fruit set at temperatures greater than 95°. Temperatures last week were above 95° several days.

Did high temperatures damages the blossoms?

Did those high temperatures do double damage on my tomato plants? Did those temperatures, more like those of July and August than June, wilt my young plants and delay their growth? Did those super-hot days damage the pollen in the first blossoms—so I will have few early tomatoes if the plants do revive?

How much drama can we stand, tomato growers?

I knew I should have done a Ph.D. in botany. “Dr. Nixon, Dr. Nixon. Please report to the Tomato Patch. Code Wilt. Code Wilt.”

Ah, fantasies—always good for a smile—as would be an enclosed Tomato Patch—perhaps a greenhouse with central heating and air-conditioning—so I could keep the temperature at exactly 78° F.—for maximum fruit set.