Purple deadnettle (Lamium purpureum) is a common broadleaf weed that can be found in open fields across the United States, but you may also find it in your Illinois lawn. You may know this annual weed as one of the most commonly foraged-for plants due to its tasty flowers and nutritious leaves, but the effects it can have on your lawn are much less savory.
If allowed to grow freely in your yard, purple deadnettle is notorious for overtaking the turfgrass and plants in your yard. Let's learn a bit more about this interesting lawn weed so you can keep your property defended against it!
Once you know what to look for in your yard, purple deadnettle is one of the easiest lawn weeds to identify. The most noticeable trait of purple deadnettle is its vibrant flowers that are usually a bright pink or purple color, and they have a symmetrical appearance in terms of both their markings and shape. These flowers technically feature 5 flower petals: 1 hooded top petal, 2 “winged” petals on either side, and 2 smaller lobes hanging off the bottom.
Purple deadnettle has a square stem that stands completely upright. This weed can sometimes grow as tall as 16 inches, but it is often found to be somewhere closer to 4-6 inches in lawns. The leaves of purple deadnettle are often described as triangular or heart-shaped with scalloped edges, and they often have a deep reddish or purple color near the flower. As the plant matures, the leaves will slowly change color to a completely deep green color.
What To Look For:
Purple deadnettle is often confused with a similar-looking weed called henbit. Distinguishing between henbit and purple deadnettle can be tricky, as both belong to the mint family, share similar growing habits, and often appear in the same locations. They both have square stems, purple or reddish leaves, and small tubular flowers, making them easy to confuse at a glance. However, subtle differences in leaf shape and growth pattern set them apart.
Purple deadnettle tends to have more distinctly triangular, pointed leaves that are densely packed near the top of the plant, giving it a tiered appearance. In contrast, henbit features rounder, scalloped leaves that directly encircle the stem without petioles. Their growth patterns also differ, with henbit often appearing more sprawling and open, while purple deadnettle tends to form dense clusters with a more upright structure. Paying attention to these small yet important characteristics makes it easier to identify each species accurately.
Purple Deadnettle (Lamium purpureum):
Henbit (Lamium amplexicaule):
Unsightly patches of purple deadnettle will appear in your lawn once an invasion begins. This weed is an aggressive grower, and it can easily take over your turfgrass and other plants if you do not take steps to control it. With its low-growing habits, purple deadnettle can be difficult to detect in a lawn, especially if you prefer your grass a bit taller. This weed uses stolons to spread its invasion along the soil surface, causing new stems to emerge all over the affected area of your lawn.
In addition to rooting at nodes and producing horizontal stems, purple deadnettle will also drop seeds all over your lawn. The more deadnettle weeds that start to appear in your lawn, the fewer nutrients will be left in the soil for your grass or other desired plants. These are the factors that make controlling purple deadnettle so important to proper landscape maintenance.
Purple deadnettle is a winter annual. Seeds germinate in fall, and the emerged seedlings survive the harsh winter conditions. Early spring is the time of year when you will notice deadnettle weeds, as the cooler temperatures early in the season are perfect for their growth. The weeds will mature quickly and are likely to produce the majority of their flowers in April, especially in cooler climates.
Purple deadnettle does not endure hot temperatures well, so the weeds will start to die as summer arrives. Before wilting, the flowers will drop seeds into the soil that will germinate again in fall. Purple deadnettle produces up to 27,000 seeds per plant, which is why removing them before they set seed is crucial.
The eastern half of the United States is known to see high numbers of purple deadnettle, but they can be found all across the country. However, since they are winter annuals, purple deadnettle weeds are not likely to be found in the deep south or other places where temperatures do not get cool enough.
This weed prefers full sun to partial shade, and it thrives in moist soils that are rich in nutrients and minerals. It grows well in disturbed soils, which is why it can be found in residential yards, gardens, near roadsides, and other areas that are close to people and civilization.
If you have followed any of our series of articles about lawn weeds, you know what we are going to say about weed control -- prevention is your best option! There are things you can do around the yard that will help deter and prevent purple deadnettle from appearing. Thankfully, though, annual weeds do not have complex or deep roots like perennials can have, so removal is possible if the invasion has not spread too widely across your property.
Call Merrill Landscape Services today for all of your weed control needs in Illinois, and keep the following tips in mind for preventing and removing purple deadnettle in your yard this season!
