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