Now is the Time to Prevent Crabgrass

May 16, 2019

By Esther McGinnis

Crabgrass seeds begin to germinate when the soil temperature consistently reaches 55 degrees.

Crabgrass is a warm-season annual weed with a wide leaf that can look unattractive to homeowners wanting a healthy lawn, says Esther McGinnis, NDSU Extension horticulturist.

Although the plants die with the first hard frost, a large soil seedbank ensures a new crop of weeds each year.

Crabgrass seeds begin to germinate in spring when the soil temperature, at a depth of 2 inches, consistently reaches 55 degrees. Seeds will continue to germinate throughout summer but the majority will germinate at soil temperatures between 60 and 70 degrees.

“With our late spring, turf soil temperatures have been slow to rise. However, the soil will warm very quickly this week with warmer air temperatures,” says McGinnis. “Now is the time to apply a crabgrass pre-emergent herbicide before we reach this germination threshold.”

To check on the turf soil temperature in your area, please consult the North Dakota Agricultural Weather Network (NDAWN) website at https://ndawn.ndsu.nodak.edu/soil-temps.html. Crabgrass preventers are a class of pre-emergent herbicides that are applied before the crabgrass seeds germinate. Most pre-emergent herbicides will not provide effective control after germination.

Commonly available crabgrass preventers include active ingredients such as pendimethalin, prodiamine and dithiopyr. Of these three herbicides, dithiopyr is the only one that has early post-emergent activity. Dithiopyr can control crabgrass seedlings that are in the one- to three-leaf stage.

“When applying a crabgrass preventer, follow all label instructions,” McGinnis recommends.

To be effective, it is necessary to apply 1/2 inch of water to dissolve the granules and move the herbicide into the top layer of soil. Once dissolved, the crabgrass preventer will form a barrier in the soil.

Do not apply a standard crabgrass preventer to newly seeded lawns. The pre-emergent herbicide cannot differentiate between crabgrass seeds and lawn seeds. Instead, products that contain the active ingredients mesotrione or siduron (Tuperan) can be used in that situation.

Source:ndsu.edu

Video: Why Your Food Future Could be Trapped in a Seed Morgue

In a world of PowerPoint overload, Rex Bernardo stands out. No bullet points. No charts. No jargon. Just stories and photographs. At this year’s National Association for Plant Breeding conference on the Big Island of Hawaii, he stood before a room of peers — all experts in the science of seeds — and did something radical: he showed them images. He told them stories. And he asked them to remember not what they saw, but how they felt.

Bernardo, recipient of the 2025 Lifetime Achievement Award, has spent his career searching for the genetic treasures tucked inside what plant breeders call exotic germplasm — ancient, often wild genetic lines that hold secrets to resilience, taste, and traits we've forgotten to value.

But Bernardo didn’t always think this way.

“I worked in private industry for nearly a decade,” he recalls. “I remember one breeder saying, ‘We’re making new hybrids, but they’re basically the same genetics.’ That stuck with me. Where is the new diversity going to come from?”

For Bernardo, part of the answer lies in the world’s gene banks — vast vaults of seed samples collected from every corner of the globe. Yet, he says, many of these vaults have quietly become “seed morgues.” “Something goes in, but it never comes out,” he explains. “We need to start treating these collections like living investments, not museums of dead potential.”

That potential — and the barriers to unlocking it — are deeply personal for Bernardo. He’s wrestled with international policies that prevent access to valuable lines (like North Korean corn) and with the slow, painstaking science of transferring useful traits from wild relatives into elite lines that farmers can actually grow. Sometimes it works. Sometimes it doesn’t. But he’s convinced that success starts not in the lab, but in the way we communicate.

“The fact sheet model isn’t cutting it anymore,” he says. “We hand out a paper about a new variety and think that’s enough. But stories? Plants you can see and touch? That’s what stays with people.”

Bernardo practices what he preaches. At the University of Minnesota, he helped launch a student-led breeding program that’s working to adapt leafy African vegetables for the Twin Cities’ African diaspora. The goal? Culturally relevant crops that mature in Minnesota’s shorter growing season — and can be regrown year after year.

“That’s real impact,” he says. “Helping people grow food that’s meaningful to them, not just what's commercially viable.”

He’s also brewed plant breeding into something more relatable — literally. Coffee and beer have become unexpected tools in his mission to make science accessible. His undergraduate course on coffee, for instance, connects the dots between genetics, geography, and culture. “Everyone drinks coffee,” he says. “It’s a conversation starter. It’s a gateway into plant science.”