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Ajuga is a plant that goes by many other names, such as carpetweed and bugleweed, to name just two. Native to parts of Asia and northern Africa, many wonder if the species will take over their landscape if introduced in a location where it’s not a native plant species.
Left unchecked, ajuga can choke out other plants and spread far beyond its original footprint. In some cases, this may be desirable, but in situations where you want a contained area of ajuga only, several effective methods exist to prevent the plant’s spread.
I’ll share information about how ajuga interacts with other plants, specifically focusing on how the plant propagates and spreads to better understand how to contain it. I’ll also share concrete tips to keep ajuga from choking out other plants in your yard and when to work it into your landscape.
Is Ajuga Bad for Your Other Plants?
When homeowners hear that ajuga has the potential to choke out other plants, the immediate concern is if ajuga itself kills other plants. Said another way, many assume that this means that it is bad for other plants.
This isn’t necessarily the case. Ajuga is not a plant that causes damage to other species. It does not release any toxin, spore, or mold that could harm your other plants. It does not scour the earth that it’s planted in.
Ajuga is only bad for other plants because it is such an aggressive spreader with dense leaves and greenery. If it isn’t contained or thinned out, it will overtake most other plant species. This is due to how ajuga grows, spreads, and propagates.
How Does Ajuga Spread?
Ajuga spreads via runners/stolons that grow laterally from the main plant. Each juncture or joint along the way establishes an independent root system below and sends up a plant above.
The stolon system gives ajuga a strong network that allows it to quickly and firmly establish its presence. The plants that grow from each juncture fill in quickly, covering bare areas with broad leaves that inhibit the growth of other plant species.
This characteristic can be both good and bad. On the one hand, ajuga outcompetes other plant species in an area. But on the other hand, it outcompetes weeds, making it a great choice to plant in a place where you don’t want to have to weed by hand.
Ajuga spreads aggressively but creeps slowly. This makes bugleweed plants relatively easy to contain in one area as long as you regularly maintain the area to keep it contained. If you want a maintenance-free bed, consider other methods to manage ajuga within a space before you put the first plant in the ground.
How To Contain Ajuga
Now that you know how ajuga or carpetweed spreads, you can better understand how to approach containing this aggressive species. Since the plant spreads by sending out underground shoots, the best containment method is to cut off or prevent the lateral stolon growth.
This can be done via a few different methods. The first method to contain ajuga is to dig deep enough around a border to bury a barrier to stolon spread. Some relatively inexpensive materials will work, but consider the life of the barrier and how long until it deteriorates or the stolons will be able to break through.
The second method to contain ajuga plants is to plant them within an area with an established edge or trench. The trench doesn’t have to be extremely deep; 4 to 6 inches (10-15 cm) is sufficient.
Since ajuga stolons spread slowly but steadily, you will be able to see when stolons peek out of the established bed and begin to jut out into the trench. At that point, you can snip them or clip them.
Note that those stolons you snip from the bed can be dipped in a rooting compound and placed in potting soil for a new ajuga plant. This is a great way to share plant cuttings with neighbors and friends who also love gardening. It also speaks to just how resilient this ground cover is.
The third and most challenging method to contain ajuga plants is to dig or pull them out of undesirable locations twice per year. Again, carpetweed is a slow but persistent species.
See our guide on How To Fully Eradicate Carpet Bugle Plants.
It only needs to be dug up or pulled out twice per year, but it’s critical that you not skip a session as those stolons continue to creep underground.
If none of these methods appeal to you, but you still want ajuga in our landscape, consider planting your bugleweed in a container. Ajuga gives lovely color, texture, and depth. Adding it to a planter helps moisten the soil and inhibits weed growth.
Best Places To Plant Ajuga
Plant experts at NC State Extension advise that ajuga is best planted in an area that is somewhat “wild” in appearance or at least not overly manicured (source). Consider planting it in an open space under a canopy of trees.
This will create a thick, uniform mat of color under the trees. A wide bed of ajuga requires no mowing or manicuring, so it’s virtually maintenance-free.
Because of the thick root systems and their ability to fill in bare patches of soil, ajuga provides great shade for tree root systems near the ground and keeps the ground from drying out too quickly. The thick nature of the plant’s colony growth system will keep undesirable weeds at bay.
Another excellent application for ajuga is on a slope or hill that tends to get washed out in heavy rains. The ajuga will systematically colonize the slope, and the web of roots will stabilize the hillside and could help prevent future washouts.
Sean and Allison at Spoken Garden give an excellent overview of bugleweed in this YouTube video:
Like any non-native species, it’s essential to understand how Ajuga grows, spreads, and thrives in any environment. Knowing the conditions that allow them to colonize an area helps you to think through how you will contain them before you even put a single plant in the ground.