You didn’t think there were only six plants we considered to be horrific, invasive plants, did you? As bad as the plants we discussed on Monday are, there are plenty more that give them a run for their money. Here are six more invasive plant species that are spreading across the United States and giving gardeners and lawn keepers headaches.
This is a shrub that spreads through using small fruits that birds and animals love, meaning that one plant can spread seed far and wide through droppings. Autumn Olive, along with its relative the Russian Olive, grow in dense stands and will choke out local plants. This invasive plant is prohibited in some regions of Canada, and is an invasive throughout the United States. It’s also difficult to eradicate – it will grow back when cut, so pulling it out by the roots is the only way to remove it permanently.
Originally introduced as a culinary herb, it has spread across the United States, thanks to the ecosystems not having the native insects and fungi that normally feed on it. Additionally, many of the common grazers in the states, such as deer, to not like the flavor of this invasive plant, and will not eat it. They will trample it though, which is mildly useful. Aside from cooking, it can also be used medicinally, consumed or used to cover and heal a wound.
Common and Glossy Buckthorn
Hard to kill, and bearing berries that are toxic to humans and animals, buckthorn is a particularly nasty invasive plant. It produces leaves early on, which means it can steal and block light from plants that might live underneath it. It is shade-tolerant, which means it can outlast the plants in darker areas as well. Controlling buckthorn is very difficult as well – the root collar will continue to sprout, through burning, cutting, or otherwise removing everything above ground. Even with killing it off, seeds can stay dormant and viable in the soil for years.
Common and Border Privet
A large shrub native to Europe and Northern Africa, it was brought over to the United States to feature in hedgerows. Unfortunately, it found advantageous living conditions in the United States, and spread quickly. It produces berries that, while beneficial to birds, are poisonous to humans. It also produces a rather strong odor that is unpleasant to most people. It chokes out and grows over native plants, and since birds love its berries, it expands its area of influence quickly.
An ornamental plant that also has medicinal purposes – most notably in the treatment of diarrhea and dysentery – purple loosestrife most often occurs in swampy, marshy areas. They tend to crowd out native species such as cattails, making them a threat to a well-balanced ecosystem. While purple loosestrife is resistant to a lot of chemical and mechanical control attempts, it’s been shown that they can be controlled by certain species of beetles.
Lily of the Valley
This is possibly more of a pet peeve, as it is not commonly seen as an invasive plant, but anyone who has had lily of the valley in their garden knows it doesn’t stay in the garden for long. The plant spreads easily throughout a garden, your lawn, and beyond. Sure, it has a pleasant scent, and can make for good groundcover in wooded areas. However, it is nearly unstoppable as it spreads underground. Do yourself a favor, and don’t plant this invasive plant.
So, as before, if you see these plants begin to encroach on your lawn and garden, begin your attack immediately. If left alone, these invasive plants can take over your garden in only a few seasons, choking out the plants you’ve worked so hard to cultivate.