I’m Looking Over a Three-Leaf Clover

White Clover

Perhaps you have noticed that many school yards around town have an abundance of weeds with white pom-poms throughout the lawns.  What you are likely seeing are patches of white clover that really thrive this time of year.  No, it has nothing to do with the students or faculty or the presence of Leprechauns.  Clovers are legumes and part of the pea family.  As a legume, their roots have symbiotic nitrogen-fixing bacteria which basically allow them to take nitrogen from the air and make it available for uptake by their roots.  Clovers can take advantage in soils that receive little fertilization by making their own and out competing the lawn and other weeds.  They can be good for soil building.  On the negative side, the flowers attract bees which can result in bee stings.  Some clovers like California Burclover produce spiny burs that can be painful on bare feet and become attached to pet’s fur.

There are numerous types of clovers in our area.  Clovers can be annuals, biennials, or perennials.   California Burclover (Medicago  polymorpha)and Black Medic (Medicago  lupulina) are very common annual clovers that invade lawns.  Both of these grow in a low prostrate manner from a single taproot and produce bright yellow flowers.  The leaflets form in threes and are oval shaped.  In flower beds you may see upright-growing sweet clovers like yellow sweetclover (Melilotus officinalis) which may grow 2 or more feet tall.  And finally you will see white (Trifolium repens) and strawberry clovers (Trifolium fragiferum) which are perennials in lawns, school yards, and parks throughout the state.  Their creeping stems can root at the nodes into the soil below. Their common names come from their mostly white or pink-strawberry flowers that can be very prominent.  The white clover also has a white cresent mark on its leaves.  Strawberry clover does not have this distinct marking on the leaves and is generally a more robust and aggressive plant.

You may wish to keep clovers in your lawn for their ability to add some nitrogen to the soils at no cost to you or you may like the appearance of the plant and its flowers.  Others of you may not like the patchy appearance of the clovers, not like to be stung by bees, or not like to be poked by burs.  Lawn fertilization will help the lawn grasses compete better with the clovers and reduce their advantage   Unfortunately, mowing will not reduce the presence of clovers, but you should still regularly mow the lawn.  The annual clovers may be able to be pulledout by the taproot after a good rain or irrigation, but established white clover patches will not be easily pulled out.  The use of selective herbicides are the best and easiest solution for these.

For more information on clovers and other weeds call Weed Man at 266-1624 or visit our website at Fresno.WeedManUSA.com.