Three look-alike attractive plants, often considered weeds, appear each spring in lawns and landscape beds: henbit, purple dead nettle and ground ivy.

These are best managed in late summer or fall rather than spring. Correct identification is essential as management techniques differ.

Purple dead nettle (Lamium purpureum) arrives each April.

Small pink flowers rise above the burgundy-red upper leaves. The heart-shaped, scalloped leaves change to green further down the short green stem.

These plants germinated the previous autumn, so they are ready to bloom first thing in spring.

A close cousin of purple dead nettle is henbit (Lamium amplexicaule).

It shares the square stem of the mint family and its mild scent.

Henbit’s round green leaves with deeply scalloped edges attach to a deep red short stem. Its pink flowers have a much longer tube than dead nettle flowers.

These winter annuals germinate in autumn, bloom in spring, set seeds and disappear during May when temperatures warm.

How can you use the life cycle of a winter annual to manage it?

Seeds of winter annuals, like henbit and purple dead nettle, germinate in the autumn.

Pre-emergent herbicide granules applied in early or mid-September will prevent the seeds from growing. Corn gluten meal is an organic option to apply in late summer.

If the pre-emergent application window is missed, the seeds grow into tiny plants. Then a different management approach is needed.

Control henbit and dead nettle with a post-emergent broadleaf herbicide liquid or granule in early November.

Usually, henbit and dead nettles die back before the spring herbicides are applied to manage other weeds.

Hand-pulling or hoeing works, but be sure to remove the whole plant, including the fibrous roots, before henbit or dead nettle sets seed.

Regular mowing will remove the flowers before seeds mature.

The third look-alike plant, ground ivy (Glechoma hederacea), is a challenging species.

This perennial has many common names: ground ivy, creeping Jenny, creeping Charlie, and others. Beware of the variegated form with white dappled leaf margins sold in nurseries.

Ground ivy is a weed that can creep into landscape beds. Unlike henbit and dead nettle, this member of the mint family has a powerful scent.

Its round evergreen leaves with scalloped margins are attached to the stem by a short stalk. The stems stay low to the ground as ground ivy sprawls across the yard.

Wherever there is a node, the square stems root into the soil. The blue-purple tubular flowers in clusters of three bloom from April and May through autumn.

Ground ivy is hard to manage. It does not respond well to control measures in spring. At best, spring herbicidal treatments suppress it.

There are no pre-emergent herbicides that work on ground ivy. Instead, wait until after autumn’s first frost, then apply broadleaved herbicides, often in combination products. Use again a month later.

Autumn is the best time for systemic herbicide applications as ground ivy actively moves nutrients to nourish the plant through winter.

Proper lawn care, especially a higher mowing height, helps manage ground ivy in turfgrass. Only apply lawn fertilizer when indicated by a soil test.

Hand-pull ground ivy from landscape beds, taking care to remove as much stem and roots as possible. A well-mulched bed makes it easier to see and eliminate this plant.

Always follow the product label for directions for the proper use of herbicides. Ask yourself if these plants really must be managed before applying a herbicide.

“Growing Green” is contributed by Diane Dorn, Lehigh County Extension Office Staff, and Master Gardeners. Information: Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613