Page 4
Warren County Connection
spots in the turf, reducing other weeds and the need for chemical herbicides. White clover greens up early in the spring and, being drought tolerant, stays green during the hot, dry, dog days of summer. Consider including white clover in your lawn just because it is an important nectar source for many pollinators. White clover is also a very valuable forage crop. Rabbits, and other wildlife, will browse it in the garden. If you have members of your household who are allergic to bee stings, you can always reduce the number of flowers by mowing beneath their height, which can reach 6 inches.
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White clover. Photo credit: Chris Evans, University of Illinois, Bugwood,org
The following chart may be useful in distinguishing the three look-alikes: Plant
Growth Habit
Flower
Prostrate, Yellow becoming Yellow woodsorrel more erect
Leaf
Smooth margins; deep indentation at tip; heart-shaped
Prostrate: Spur at tip; center mat-shaped; Yellow inflo- leaflet has longer petiBlack medic does not rescence ole; pair of stipules at have nodes base of leaf stem Prostate White, growth from sometimes White clover center pinkish, incrown; roots florescence at nodes
Serrated margins; slight indentation at tip; white, V-shaped watermark
All three of these look-alikes are turfgrass weeds that can be reduced through improving the quality and thickness of your lawn. It may be of interest to note that white clover was included in grass seed mixes until the development of broadleaf herbicides in the 1950s. At that point it became a goal of the herbicide companies to influence homeowners to have a "perfect" lawn, free from all broadleaf weeds, including white clover.
It is with good reason that white clover was historically considered part of a healthy lawn. Like other members of the legume family, it takes nitrogen from the air and "fixes" it into its root system. This nitrogen becomes an available fertilizer for the grass. This symbiotic relationship reduces or can even eliminate the need for supplemental nitrogen fertilizer. White clover will fill in empty
St. John's Wort Hypericum perforatum F. Hypericaceae General Description: St. John's wort is a low-lying herb measuring 30-75 cm. in height. The radially symmetrical flowers have bright yellow petals with distinctive black dots. The leaves are small, elliptical, and spotted. Flowers: The radially symmetrical flowers of St. John's wort are small, measuring 2-2.5 cm. in width. The blooms have five rounded petals with distinctive black spots, numerous stamens, and 3 styles. Flowers are arranged singly atop the terminal shoot of the stem. Leaves: The leaves are small, measuring 2.5-5 cm. in length and are light green and elliptical with distinctive, translucent spots/irregularities. Leaves are arranged in an opposite fashion along the length of the stem. Habitat: St. John's wort grows best in fields, along roadsides, and around waste areas. Fun Facts: St. John's wort is a medicinal plant. Commercial pill forms of the plant extract is used to treat depression. However, it causes increased sensitivity to the sun as well. St. John's wort also causes photodermatitis in grazing animals. This wildflower was introduced from Europe. Source: http://www.bio.brandeis.edu/fieldbio/ Wildflowers_Kimonis_Kramer/PAGES/SEARCH_NAME_HOME.html
