Spring Weeds in Turf Grass

Story and photos by Joanne K., Pitt County Arboretum Extension Master Gardener Volunteer

Although our grass does not actively grow in winter and early spring, the weeds certainly do! They seem to pop up everywhere in the lawn, causing headaches for grass lovers.

Weeds are defined as plants growing where you don't want them. Most of the same weed species will return in the same areas every year. Weeds compete with the grass for light, water, nutrients, and space.

This time of year you are likely to see a variety of broadleaf weeds, including Henbit (Lamium amplexicaule), Hairy buttercup (Ranunculus sardous), Dandelion (Taraxacum officinale), Purple deadnettle (Lamium purpureum), Wild garlic (Allium ursinum), and Wild violets (Viola papilionacea).

Weeds can reproduce not only through seeds but also through root and stem fragments, underground rhizomes, and tubers. Anyone who has tried to eliminate wild garlic knows how tough that is to do.

Viola papilionacea (blue violet)

Lamium purpureum (purple deadnettle)

Weeds love to move into barren dry soil, compacted soil, or perpetually damp areas. The best defense is a dense healthy turf whose shade will prevent weed seeds from germinating and slow water evaporation.

Proper mowing heights, applying fertilizer at the right time, sufficient water, thatch control, and weed and insect control are all critical to maintaining a healthy turf.

Weeds that appear now are best controlled in November or December with a treatment of a preemergent herbicide containing mesotrione, MOA 27 (4 SC) or sulfentrazone + prodiaminel, MOA 14 + 3 (4 SC).

If you missed that window, a number of postemergent herbicides can be used now, including those containing quinclorac, MOA (27 +4); 2,4-D amine, MOA 4 (4 SL); mecoprop, MOA 4; or dicamba MOA 4 (4 SL).

Before selecting a herbicide to use, it's important to identify both the weeds to be controlled and your grass type.

Also, always be sure to carefully read all of the instructions on the herbicide packaging to ensure the safe application of the product.

Ranunculus sardous (buttercup)

These include calculating the square footage, measuring the herbicide amount accordingly, and correctly calibrating the spreader.

An excellent resource is the turf grass file at NC State University: https://www.turffiles.ncsu.edu/weeds-in-turf/

The NC State University website describes the various weeds that occur at different times of the year and includes pictures for identification. It describes cultural and chemical controls listing the pre- and post-emergent herbicides that can be used, along with explanations on their usage.

Lawn maintenance calendars can be requested from the Pitt County Extension Master Gardener Volunteers by calling the Info Line at 252-902-1709.