What Are Winter Weeds

In the Arizona desert area like the Phoenix Metro area our climate leads to much different growth patterns that found in the rest of the country.

Weeds compete for water, nutrients and sunlight and reduce the vigor and growth of ornamental landscape plants. A weed is any plant that interferes with the management objective for an area of land at a particular time. Weeds are usually plants that are very prolific, invasive, competitive, harmful, destructive, or difficult to control. Weeds detract from the appearance of landscapes and can be hosts for disease causing organisms and insects. They may also provide shelter and food for insects and rodents that feed on ornamental plants and invade buildings. The important aspects of this weed definition are that a plant is a weed only in the eyes of the person considering it a weed and that a plant is only a weed at a specific time and place. Thus, landscape managers should be cautious about using weed control measures such as soil sterilents that preclude alternate land uses in future years.

Annual plants live for only one growing season. They are referred to as winter annuals if they germinate, grow, flower and produce seed during the fall and winter or as summer annuals if they germinate, grow, flower and produce seed during the spring and summer. Common summer annuals in desert landscapes include spurges, pigweeds, and puncturevine. Common winter annuals include London rocket, thistles, little mallow, redstem filaree, annual bluegrass, mediterraneangrass, and wild barley.

Biennial plants require parts of two seasons to grow, flower and produce seed. In Arizona, biennials typically germinate in the fall, grow a basal rosette of leaves during the winter, and then flower and produce seed in the spring and early summer. Some annual weeds in Arizona may grow as biennials during parts of two seasons when favorable moisture and temperature conditions exist (e.g., camphorweed, little mallow, and Russian thistle). Biennials are not common in Arizona, are not that different from winter annuals in our climate, and can be managed using the strategies discussed for annual weeds. The survival or reoccurrence of annual and biennial weeds in a landscape depends on the production of seed by weeds in the landscape and on the movement of seeds in to the landscape by animals, wind, and water.

Being able to distinguish between dicot and monocot weeds is important because some herbicides will control dicot but not monocot weeds and vice versa. In addition, herbicides that control grasses may not control sedges. Purple and yellow nutsedge are two common sedges in Arizona landscapes that can be very difficult to control because they are perennials with extensive underground root and rhizome systems. 

It doesn’t matter to us whether you want desert landscaping, lush lawns or some type of landscaping in between, we can help.  We serve businesses like yours all over the Phoenix Metro Area. To find out how give us a call at 623-848-8277.

Presented By:
Greens Keeper Landscape Maintenance, LLC
623-848-8277
http://www.commerciallandscapecare.com
greenskeeperllc@cox.net