Lawn Weeds Identification: Common Lawn Weeds
Common name of the most common lawn weed is Salvia officinalis (Salvia). It is a perennial herbaceous plant growing up to 3 feet tall. Leaves are opposite, 1/4 inch long and smooth.
Flowers are white or pinkish purple, and have 5 petals each. They grow from stems 2 inches high, which can be seen at any time during the day when they open. They bloom only once per year. Seeds are spherical, greenish brown, and have 4 seeds each.
The leaves are used as food source by birds and insects. The flowers attract bees and butterflies, which pollinate them. The seed pods contain edible fruit, but it is not known how many seeds there are in the pod.
Weed Symptoms & Effects:
It is very difficult to tell the difference between Salvia officinalis and other common weeds. However, it is easy to distinguish the Salvia from its relatives. The leaves of Salvia are slightly hairy, while those of other weeds are smooth.
Other than these differences, all common weeds look similar. There may be some minor differences in color and texture, but none of them are noticeable enough to cause concern for gardeners or landscapers. Salvia grows very fast, in most cases faster than other weed species. It is also resistant to herbicides.
It is a common misconception that Salvia is toxic and can harm children and animals. In fact, salvia isn’t the problem, but it’s the rain water after a rare sunny day that contains high concentration of Salvinorin A. This ingredient is absorbed through skin and metabolized in the liver.
It affects the brain by activating kappa opioid receptors, which results in hallucinations. Salvinorin A is also a dangerous ingredient in research studies that look for treatment of opiate addiction. This drug is about 10,000 times more powerful than morphine.
The best way to get rid of Salvia is by digging it out, but herbicides are an option as well. Salvia can be spotted during any month of the year, but it is known to grow better in soil that doesn’t contain too much nitrogen. It grows better in new lawns that have not yet been fertilized.
Other common lawn weeds are Dandelion, Plantain, and Vetch
Dandelion (Taraxacum officinale)
Dandelion is a common weed that grows in lawns, fields, sidewalks cracks and other open areas. It is also known as “puffball”. It has a milky juice, and grows from a white taproot.
Leaves are lobed, toothed, and have hairs on the bottom. It is one of the largest weeds.
Plantain (Plantago major)
Plantain is an edible weed that can be used in salads or other meals. It can also be crushed and applied directly to skin to treat rashes or bee stings. It is a common weed found everywhere, including lawns.
It has long leaves, and grows from a white taproot. It is known for its ability to grow in almost any condition, including concretes and other man-made structures.
Vetch (Vicia villosa)
Vetch is a legume that grows in poor soil, hence the reason why it grows in lawns. It has pea-like blossoms and hairy vines. It has a tendency to grow very quickly.
In some areas it is known to be an invasive weed that takes nutrients from other plants near it, eventually killing them.
Sources & references used in this article:
Floristic composition of weed community in turf grass area of west peninsular Malaysia by MD Kamal-Uddin, AS Juraimi, M Begum… – International Journal of …, 2009 – academia.edu
Control of Turf grass Weeds by LB McCarty, TR Murphy – Turf weeds and their control, 1994 – Wiley Online Library
Destructive turfgrass insects: biology, diagnosis, and control by DA Potter – 1998 – books.google.com
Pollinator assemblages on dandelions and white clover in urban and suburban lawns by JL Larson, AJ Kesheimer, DA Potter – Journal of insect conservation, 2014 – Springer
Weeds of southern turfgrasses by TR Murphy, DL Colvin, R Dickens, JW Everest, D Hall… – 1992 – archive.lib.msu.edu
All about weeds by ER Spencer – 2013 – books.google.com
St. augustinegrass for Florida lawns by LE Trenholm, JL Cisar, JB Unruh – 2000 – nwdistrict.ifas.ufl.edu