Identifying early spring weeds


OSU Extension Today

By Kim Hupman

Weeds, those ingenious plants designed by nature, to cover any bare, disturbed ground as quickly as possible. We do our best to combat these invaders with every tool available. The best and first tool to use is positive identification. Correctly identifying the offending weed will give you the methods you need to control the weed. There are three early spring weeds often mistaken for each other.

They are henbit (Lamium amplexicaule), purple deadnettle (Lamium purpureum) and ground ivy or creeping Charlie (Glechoma hederacea). All three are members of the mint family sharing similar characteristics that make them easily identifiable such as, square stems, tubular shaped flowers of purplish color.

Henbit (Lamium amplexicaule), (pronounced LAM-ee-um am-plex-i-kaw-lee) tends to be a late winter weed and can be noticed in the fallow fields. The leaves are opposite; kidney shaped and has rounded deeply toothed margins. The lower leafs have short petioles while the middle and upper leafs have no petioles. The upper leaves tend to clasp the stem, hence the name amplexicaule which means stem clasping.

The five –lobed flowers are a purple color, tubular and arise from the top of the leave. Henbit is an annual. It completes its life cycle in the early spring by producing seed that will either over winter or germinate in the late fall. It is easily controlled with a pre-emergent herbicide in the fall or/and a post emergent herbicide in the very early spring when the weeds are still in a juvenile state.

Purple deadnettle (Lamium purpureum) (LAM-ee-um per-per-EE-um) leaves are triangle to heart – shape and opposite. The flower is similar to Henbit but tends to come below the leaves. The petioles are prominent on the lower leaves becoming shorter as the leaves ascend up the stem.

The leaves tend to be closer together toward the tip and the new leaves generally have a reddish to purplish tint to them. Purple deadnettle is an early spring/late fall annual that is controlled by pre-emergent herbicide in the fall or post-emergent herbicide in the spring. The key is not to let either of these annuals to go to seed.

Creeping Charlie (Glechoma hederacea) (Glee-KO-muh hed-ur-AY-see-uh) has the square stem, tubular purple flower and a distinct odor when crushed. The leaves have round toothed margins and are kidney shaped similar to Henbit.

The difference is Creeping Charlies’ leaves have petioles on each leaf where the upper leaves of Henbit have none. Creeping Charlie is a perennial weed which requires a different control approach. Pre-emergence herbicides are not an effective control method. Post-emergent herbicides applied in the fall will give the best results.

Always read and follow the directions when using any pesticide it is the law. Accurate identification is the first step to creating a successful management plan. If you are unsure, bring your sample to the OSU Extension Greene County office.

OSU Extension Today

Kim Hupman is a horticulture program assistant at OSU Extension Greene County.

Kim Hupman is a horticulture program assistant at OSU Extension Greene County.