Holly Scott was concerned that moving the washer and dryer out of the basement would hurt the houseplants.

Coffee-lover Peyton Hyde wondered whether her mom was right when she’d say that caffeine would stunt her growth.

Good thing it was time for the Hamilton Rotary Club’s Science Fair.

What better opportunity to prove your mother wrong?

The Garfield Middle School eighth-graders were among 180 students working on 125 projects for the annual event, open to Hamilton City School students in grades eight and 10.

“The Hamilton Rotary Club and the Hamilton City School District have been doing this for over 60 years,” said event chairman David Mancuso.

Students can compete in 12 different categories and earn cash prizes. The amount varies depending on the distribution of scores, but this year, students earned $20 for a Superior score, $25 if they also took first place in their category. The money is provided by the Rotary Club’s Andrew Kornylak fund.

Mancuso said that it takes about 80 adult volunteers to run the show, about 50 of them coming from Rotary Club ranks. The rest are volunteers from other civic organizations, area businesses and Miami University Hamilton, which hosted the event on Friday.

Mancuso said that the quality of the Science Fair presentations improved dramatically a couple of years ago when the Rotary Club started encouraging English teachers as well as science teachers to get students involved.

Hyde, Scott and several other students examined the effects of outside influences on the growth rate of plants. Grass, it seems, was a common test subject.

“It’s not practical to test on mammals because their growth is too slow,” Hyde said.

Hyde added varying amounts of caffeine to the water of the grass she had planted in identical containers and fed them every three days for two weeks. While she found that caffeine “pretty significantly” stunted the growth of grass, she hasn’t given up coffee.

“I’m done growing anyway,” she said.

Scott wasn’t sure what kind of seeds she used, but she added varying amounts of detergent to the soil of three different plants, which she would then water every 12 hours, and she discovered a correlation between the growth rate of plants and the amount of detergent in the soil.

Abby Tompkins, a sophomore, tested how colored light affected how the grass grows. Pink and blue works best, she discovered, but green light interfered with the plants’ photosynthesis.

A pair of dueling projects had mixed results to determine whether music would make the grass grow better. Sophomore Laney Blevins discovered that plants listening to classical music four hours a day grew better than plants listening to four hours of rap or rock music each day.

Amanda Haley and Shelby Bushnell, however, gave their plants a steady diet of music for two weeks and found that the rap grass out-performed the classical grass by more than double.

Rap, it would seem, takes some getting used to.