Bicolor Lespedeza is a deciduous shrub that was initially introduced for soil stabilization and as a food source for wildlife, including bobwhite quail, whitetail deer, and cottontail rabbits. However, it has since become invasive, displacing desirable vegetation in habitats like forests and large openings.
The weed forms dense stands, can regrow from root crowns, and has a long-lived seed bank, making it an important weed to eradicate once sighted.
If you’re dealing with Bicolor Lespedeza infestation, here are a few details to help you in correctly identifying the weed and a list of mechanical, chemical, and long-term monitoring strategies to help you get rid of the weed for good.
How to Identify Bicolor Lespedeza
Before we delve into the removal methods, here are a few pointers to assist you correctly identify the weed.
Bicolor Lespedeza is a semi-woody shrub that can grow 8-10 feet in height.
Stems are upright, slender, and much-branched at the top, giving the weed a bushy appearance. The flowers grow in racemes on the tops of stems and in the leaf axils. The pea-like flowers are pink to purple in color.
1. Pulling and Digging of Young Plants
Hand-pulling is effective for getting rid of young plants, especially if done when the ground is moist. Digging out the plants and uprooting the entire root crown can also prove helpful for isolated shrubs.
Ensure that you collect and bag all the cut material to prevent regrowth. Also, restore the area with native vegetation to prevent re-colonization.
2. Chemical herbicides
For moderate to larger infestations, chemical herbicide application is necessary. The best time to apply a herbicide is when the foliage is actively growing and before seed set.
The herbicides you can consider include triclopyr, glyphosate, metsulfuron-methyl, hexazinone, and aminopyralid.
For the best results, consult your local extension expert on the herbicide choice, depending on the size of the infestation, surrounding vegetation, and local regulations.
3. Adjust Site Conditions
Adjusting site conditions to reduce Bicolor Lespedeza vigor is another strategy you can consider.
These strategies include:
- Increasing shade since the weed thrives in full sunlight.
- Lightly enriching the soil with compost to favor native competitors.
- Limit mowing and burning as they can stimulate flush growth if not followed by herbicide control.
By applying these measures, where appropriate, you make the environment inhospitable for Bicolor Lespedeza.
How to Prevent Bicolor Lespedeza Growth in Your Landscape
Bicolor Lespedeza is a stubborn and invasive weed due to its spreading and growth adaptations. However, there are strategic measures you can apply to prevent regrowth and time-consuming weed control.
1. Target the Root Crown
Bicolor Lespedeza develops a root crown or a woody base that allows the growth of new shoots even after cutting or burning the top.
When digging, ensure that you remove the root crown and dispose of all the small fragments to prevent re-sprouting. Alternatively, you can spot treat the cut stumps with herbicides like triclopyr or glyphosate to eradicate them.
2. Deplete the Seed Bank
The weed’s long-lived seed bank can keep you on the defensive for several years. To stay ahead, pull or cut the weeds before seed set. That way, you gradually deplete the seed bank every season.
You can also lay a thick layer of mulch or grow native plants like grasses or other towering herbs that can inhibit the weed’s germination by blocking sunlight.
3. Monitor and Establish a Long-Term Control Plan
Since seedlings and shoots will often appear in the next season after the first control plan, don’t think of eradication as a single event, but as a long-term process.
Schedule monthly checks (especially during the growing season) to map out the hotspots for resprouting clumps. Then quickly deploy the appropriate control strategy, whether that’s hand-pulling or a herbicide treatment.
4. Establish Dense Vegetation
Bicolor Lespedeza prefers open and sunny areas with little competition. Re-establishing native grasses or fast-growing shrubs will create shade and minimize space for Lespedeza growth.
The perennial vegetation can also create long-term competition, eliminating the need for expensive and time-consuming weed control.
Lead Editor for Insight Weeds.