Life Cycle of Winter Annual Weeds In Your Lawn and Landscape

winter annual weeds

In the world of weeds, there are three different life cycles – annual, biennial and perennial. Annuals only live for one growing period, biennials live for two years and perennials live for more than two years. Among these life cycles, there is also a distinct as to when the initial germination takes place. The common thought is that all weeds germinate in the spring, but many of them germinate in the fall, such as Dandelions, Henbit and Shepard’s Purse. These life cycles are referred to as winter germinating weeds.

Winter Annual Weeds In Your Landscape

Winter annual weeds are often the first ones seen in the spring. The germination process usually begins in the fall and the plants persist over the winter in a vegetative state. They can survive freezing temperatures and be ready to start growing again once the weather begins to warm up in the spring.

As the weather warms up, the plant will begin to bolt, or send up a flower stalk or stem as their life cycle continues. This is the time that the plant produces seeds to perpetuate the species. By that time, the weather has usually started to get warmer, which signals to the winter annuals that their life cycle has come to an end.

It is important to remember that when a plant produces flowers, it also is creating seeds and those seeds will be present in the lawn to germinate the following fall and the whole process will start again. Applying weed control products in the spring is important, but it is equally important to treat a lawn for weeds in the fall as well.

Common First Winter Annual Weeds of Spring

Henbit

Henbit is a member of the mint family and has square stems with opposite leaves. It has pink to purple flowers and usually grows about 6 inches high in the Midwest. The plant has circular or rounded leaves with rounded teeth on the leaf edge or margin.

Shephard’s Purse

Shepherd’s Purse grows 3 to 18 inches tall and forms a rosette that is like a dandelion. The main difference between the two plants, besides the obvious of a Dandelion being a perennial and Shepherd’s Purse being an annual, is the shape and direction of the lobs on the leaves. The lobs on a Dandelion point back to the center of the rosette while the lobs of Shepard’s Purse point straight out from the mid vein. The seedpods are heart shaped and contain hundreds of seeds.

Common Chickweed

Chickweed has a shallow fibrous root which grows best in moist, cool shaded areas. It has small white flowers with 5 petals that are split almost to the base. The leaves are bright green and are about ½ inch long, smooth and sharply pointed.

Prickly Lettuce

The distinguishing feature of this weed is the deeply lobed leaves with a prominent row of spines on the underside of the mid vein.

Catchweed Bedstraw

This weed also has square stems with short hooks on the stems. It grows best moist shady areas. The hooked spines cling to just about everything and are difficult to remove. And it was used as a filling for mattresses.

There’s a lot more types of winter annual weeds. These weeds may be growing in your lawn now, but remember, they actually starting growing last fall. They will die when the weather turns warmer, but they will leave behind hundreds of seeds, ready to germinate again next fall. If you have any questions, feel free to contact your local Spring-Green!

Winter Weed Control On Warm-Season Grasses

warm season grass

This picture is a Bermuda grass lawn in Opelika, AL entering dormancy. Each year, as the temperatures drop, this is what happens to most warm season grasses when exposed to freezing temperatures. They take on this almost camouflage-look to them.

Except for parts of Florida, most warm season grasses enter into a dormant state during the winter. They will turn brown and do not green-up until next spring through early summer. Even though the grass turns brown, there are still broadleaf weeds and annual grasses that continue growing throughout the winter dormant period.

Types of Winter Annual Weeds

The broadleaf weeds are classified into annuals and perennials. They can also be broken down into winter germinating and summer germinating weeds. Winter weeds germinate in the fall/winter, grow throughout that period and then die when the warm weather returns the following year.

These plants will produce flowers and seeds during that time, which will then germinate again next year. That is why applying a weed control application or two during the dormant-turf period will help to eliminate these weeds from your lawn.

Most broadleaf weed control products will take care of the majority of the winter annual weeds like Henbit, Large Hop Clover Poa Annua and Chickweed.

One good thing about warm-season grasses turning brown in the winter is that weed control applications from Spring-Green can be used on grassy weeds like annual bluegrass and Dallisgrass.  The grass you wish to control are often still green and growing while the desired grasses are dormant.

Controlling Winter Annual Weeds

Now is a good time to apply a pre-emergent weed control product to prevent many annual grasses from germinating. As the name implies, these products will control these problem weeds, like crabgrass, from germinating in the spring. Once the pre-emergent application is completed, it’s important to water the lawn at least half an inch to ensure it reaches the grass root growth, especially of there is no rain in the forecast.

Even though your yard may be brown during the winter, keep in mind this is completely normal during this time. There are a few tasks that you can still do to have a more weed-free lawn next year. If you have questions on winter annual weeds or lawn maintenance, contact your neighborhood lawn care professional at Spring-Green.