Rainy conditions present mixed bag for foliage

By: Sarah Wojcik | C&G Newspapers | Published August 7, 2013

 Plants suffer root-rot from an excess of rain.

Plants suffer root-rot from an excess of rain.

Photo by Erin Sanchez

The onslaught of rainy weather lately presents pros and cons for flowers and plants.

Fungi are among the largest problems, greenhouse employees report, while on the other hand, the extra water promotes growth and also decreases the labor needed for keeping plants hydrated.

“Black spot and powdery mildew are humidity-related (fungi) because of the extra moisture in the air and the ground,” said Mike Maran, the grower at Telly’s Greenhouse in Shelby Township. “And we have to fight fertilizer issues — the rain leeches it out and we have to feed the plants again.”

Powdery mildew resembles talcum powder, while black spot appears as small dark lesions, both appearing on a plant’s leaves.

Once the spores germinate and fungus appears on a leaf, however, it cannot be removed, Maran said.

“The only thing you can do is preventatively spray for the funguses and keep plants spread apart so they can get a good airflow,” Maran said. “And try to keep plants dry at night — moisture and darkness is what fungus needs to reproduce.”

Fungicides are available at most greenhouse and nursery locations.

Maran suggested watering in the morning instead of at night and turning off sprinklers after it rains, so long as you remember to turn them back on later.

He said that some of the crop schedules are off a week or two, due to the rain.

“However, the rain does have its benefits, too,” he added. “We don’t have to water as much outside. And the grass is growing like crazy.”

Janie Saltarelli, manager at Auburn Oaks Nursery in Rochester Hills, agreed with Maran, and said the hard-hitting rain the area has seen lately compacts the soil.

“We haven’t had a lot of sun shining, so things aren’t forming new buds very fast,” she said. “It just isn’t too good for the flowers when you get that much water all at one time.”

Saltarelli said the ideal amount of rain is around one inch per week, with some sun to dry things out.

Ed Hessel, owner of Hessel’s Greenhouse in Shelby Township, said that while the rain and cooler weather has not promoted the growth of flowers, there is still a lot of green, and due to a cooler spring, the recent heat spell perked up some plants.