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weeds that grow in michigan

Weeds that grow in michigan

Glossy buckthorn (Rhamnus cathartica) is a small tree with very bad habits. It leafs out early in spring and keeps its leaves far into fall, effectively shading out native plants wherever it sprouts. Since it can thrive in woods, sun, wet areas and dry, it’s a serious threat to native ecosystems of all kinds, as well as gardens. The seeds don’t travel far on their own. Birds eat and then drop them where they roost so the trees are common along fence lines. Fast growing, the gardener must patrol for and pull them at least once a year, and try to locate and remove the mature plants which are providing the shiny black berries. One thing gardeners can be thankful for is the plant’s shallow, fibrous root system – far easier to pull than other woody weeds such as mulberry and tree of heaven.

The native perennial, enchanter’s nightshade (Circaea canadensis) is rarely seen in sunny gardens but can drive a shady gardener wild, especially when the buried seeds ripen (right photo). In seed, it seems to pull out easily and completely, but careful loosening of the soil before pulling will reveal the new, white, nearly-detached perennial roots (left photo) which can lie quietly until the next spring.

Mexican bamboo, Japanese knotweed (Polygonum cuspidatum). Perennial, up to 9 feet tall, spreading far and wide from established clumps by stout underground runners (left). Jointed, hollow stems explain the common name “bamboo.” The center section of stem has been eliminated in this photo for clarity’s sake. Grub out the roots or apply Roundup and be prepared to kill remnant sprouts for a season or two.

Perennial, wickedly persistent Canada thistle—Cirsium arvense, which is not native, despite its common name. A stem and a basal clump are shown here, left of the glove. Note the running roots, which can persist and keep sprouting even through a year or two of frequent pulling or spraying with herbicide. The key to control is to be even more persistent than the plant and to adopt as a mantra what Edwin Spencer writes in All About Weeds, “…any plant can be killed—starved to death—if it is not permitted to spread its leaves for more than a few days at a time.” The annual prickly sow thistle (Sonchus aspera), immediately right of the glove, and biennial bull thistle (Cirsium vulgare), far right, are weedy but not nearly so much trouble to eliminate. Just keep pulling or cutting the annual and biennial thistles before they set seed, and keep the area well mulched to prevent existing seed in the soil from sprouting.

Glossy buckthorn

To best the beasts on this list, beat them at their own game. After you roust out every bit of green and as much root as you can reach, post a guard. Expect new shoots within a week. Find them and cut them before they can return to the root the starch they used in reaching the sun. Be vigilant in this follow up and you will gradually exhaust the weed’s reserves.

Violet, common blue violet (Viola sororia). Perennial, often tolerated in gardens for its blue-violet flowers in spring, yet hated for colonizing nearby lawn. A typically schizophrenic approach by gardeners! Either accept it in both places or eliminate it from both. Like ground ivy, it can be killed in lawns with broadleaf weed killer—may take repeated applications—but will then return from seed if the grass is not pampered until thick enough to shade out the seedlings.

These are some of the warriors you’ll have to kill and kill again. They are weeds that cause people to shake their heads even as I answer their question, “How do I get rid of…” The gardener may even smile ruefully while saying over and over, “No, I’ve tried that.”

Enchanter’s nightshade

Pokeweed (Phytolacca americana) is an impressive, statuesque plant draped in purple-black berries in fall. Birds love this native fruit – although it is quite toxic to humans – but gardeners wish their feathered friends would eat all of the berries before they fall and then not excrete any! This photo shows the berries of an established plant – up to 9 feet tall and wide – and the roots of seedlings just 4 months old (center) and one month old (right). The roots don’t run but they do delve deep, so pull them early or be prepared to dig deep.

These weeds earned places on this list by their tendency to present a false face or ride in on invited guests. Once their true natures and their avenues of entry into a garden are known, they are relatively easy to eradicate with informed pulling and thorough mulching.

Weeds that grow in michigan

Woodland horsetail
Equisetum sylvaticum

Field horsetail
Equisetum arvense

Your description of a plant looking like a small pine, however, sounds like one of the native horsetails (Equisetum species). There are two possibilities:

1. Equisetum arvense (Field horsetail) is the most likelly possibility. It has roots that are described by Flora of the Canadian Arctic Archipelago as “pallid-brown, or red brown, or black”. It also has underground stems (rhizomes) that are “dull brown”.

ANSWER:

From: Oxford, MI
Region: Midwest
Topic: Invasive Plants, Plant Identification
Title: Invasive spreading weed in Michigan that looks like a small pine tree
Answered by: Nan Hampton

Michigan State University describes it as “a weed of landscape beds and low-lying areas.” Oregon State University offers strategies for controlling field horsetail and here is more information about controlling it from Penn State Extension and the Pacific Northwest Weed Management Handbook.

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

QUESTION:

Field horsetail
Equisetum arvense

You don’t mention flowers. Your plant will eventually have flowers unless it is one of the horsetails or other non-flowering plants such as a fern. If it is a flowering plant, when the flowers do appear it will be easier to identify. If you still can’t identify it after it blooms, you should photograph it and visit our Plant Identification page to find links to several plant identification forums that will accept photos of plants for identification. Be sure to read the Important Notes on that page before submitting your photographs to any of the plant identification forums.