Invasive weed

Asked May 15, 2018, 4:37 PM EDT

One small patch 2x4 feet - 5 days later it spread to approx 6x30 ft engulfing an entire flower bed. It is bright lime green very fine tiny delicate almost lacy leaves and plant is 7-8” tall, grows in clumps and spreads like crazy under my blue spruces which have been trimmed up. Totally engulfed my grape hyacinths, tulips , and hostes. I have never had this before and need to know how to get rid of it. I have a problem back so cannot pull it out plus, this would take days.

Wayne County Michigan

1 Response

Although it is difficult to see clearly, I believe your weed is either carpetweed or cleavers--if you go on-line, you can find a photo to compare your plant to. Either one is difficult to remove. You have the following options:
1. Pulling it out, but you say that this is difficult for you because you have back problems.
2. Use a herbicide. However, the weed is growing under your blue spruces and I would hesitate to use a herbicide under trees. Any broad spectrum herbicide would kill everything including the tulips and hyacinths. Glyphosate can be used but should be in the original format--not mixed with other chemicals such as Imazapyr which could be extremely toxic to your trees. The original format can be purchased from farm suppliers. (To read about the effect of herbicides on trees, I suggest you go to which is a website of Dr. Dave Roberts, the tree diagnostician at MSU. Click on General Articles under Landscape Tips and scroll down to 'Is Roundup Glyphosate?') Also, if you have healthy blue spruces, you need to protect them against unnecessary stress which herbicides may cause.
3. There is a final alternative but it too would be difficult with a sore back and it would also kill all the plants including your bulbs. You can smother the entire area. Cover the area with paper, either newspapers (3 sheets thick) or brown paper (cut up yard waste bags), water the paper down and cover with 2-3 inches of shredded bark (mulch) making certain that the bark is several inches from the trunk of the spruce. If there is mulch up against the tree trunks, it will rot the bark.