The existence of weeds evokes a number of human reactions – fear, anger, complacency, defensiveness, tolerance, acceptance. Well, in some gardens, maybe not accepted. It’s hard to accept that weed seems destined for world domination. Especially the bermudagrass and bindweed in my garden that require an annual reassessment of why I love to garden.
Plus, the world of weeds is adrift with outlook – what’s one person’s weed is another’s favorite flower. For example, henbit, also known as red nettle, (Lamium amplexicaule) may be unwelcome to some gardeners, but to another henbit is beautiful and poetic.
Definitions of weeds can vary – from plants that grow where they are not wanted, to those whose undesirable qualities outweigh the good ones. In some gardens, a weed is a plant that is moved or sown unintentionally, or that bothers us. Ralph Waldo Emerson once wrote, “What is a weed? A plant whose virtues have not yet been discovered.
Our understanding of weeds generally highlights the negative characteristics of weeds. Weeds compete for nutrients and water in our gardens and can block sunlight and choke out desirable plants. Weeds surrounding tree trunks can harbor pests and promote disease, with some harboring overwintering pests.
Despite the negative attributes of weeds, some crop scientists oppose certain beneficial qualities, such as soil retention, erosion prevention, and compaction breaking. Many weeds also provide excellent sources of pollen and nectar for bees and other beneficial insects, as well as habitat for soil microbes. Many are grown for medicinal or nutritional purposes.
Regardless of outlook and attitude towards weeds, their emergence at this time of year poses a challenge to even the most seasoned gardener. There are many ways to deal with these unwanted plants that invade our new seedlings.
Integrated Pest Management (IPM) offers several choices in managing weeds. Well known to many gardeners, IPM helps gardeners solve pest problems using a process that minimizes risk to humans, animals and the environment. IPM includes pests, plants, vertebrates, invertebrates, pathogens, or other undesirable organisms that can harm water quality, animal life, or other ecosystem components . A science-generated decision-making process, IPM requires first observation and correct identification of the pest, followed by an assessment of the number or extent of damage caused by the pest harmful. Guidelines are available on IPM sites to help gardeners decide which strategy or combination of strategies to use, such as biological, cultural, physical or chemical controls.
First, it is essential to identify a pest – in this case weeds which can be annual or perennial and can be characterized as persistent and competitive, some with seeds which can survive in the ground for a long time . To identify which weed may be invading your space, the UC IPM website offers an online tool that can help home gardeners identify weeds. the to place classifies weeds into four categories: leafy (herbaceous, flowering); sedges (perennial herbaceous plants that grow in shallow water or very moist soils); grasses (narrow leaves with parallel veins and small inconspicuous flowers); and aquatic plants (plants that grow in water for at least part of their life cycle). Each category includes a tutorial with images describing each type.
Once the weed is correctly identified, and with the help of IPM sites, weed management can be considered. Options include mechanical/physical, biological, cultural and chemical controls. One of the most common methods is probably the mechanical/physical method which, in simple terms, is to get out there and pull the weeds out! UCANR weed specialists suggest that most weeds can be managed by hand weeding, mulching and other non-chemical methods.
To learn more about weeds and their control, plan to attend the UC Master Gardeners of Nevada County, free outdoor public workshop, “Weeds – The Good, The Bad, The Ugly,” on Saturday, April 9. , from 10 a.m. to noon at the Demonstration Garden on the NID Business Complex (1036 W. Main Street) in Grass Valley. We will explore the history of weeds and how they fit into our landscape, weed problems and benefits, common local weeds, and management strategies using IPM methods.
Another strategy for avoiding weeds is to plant in containers. To find out more, join the Master Gardeners for the first outdoor workshop of our season, “Container Gardening” TODAY at 10 a.m. at the Demonstration Garden (address above). Maybe your growing space is limited, or deer and other pests are getting the better of you – maybe container growing would be a good alternative. Almost any plant, including bulbs and herbs, can be grown in a container, if you know how to care for it.
Other Master Gardener activities this spring include more in-person public workshops, and our popular Spring Plant Sale is underway Saturday, May 7, from 9 a.m. to noon. As in the past, master gardeners are now busy cultivating hundreds of vegetable, herb and flower seedlings for sale. Mark your calendars now. Check our website often for more information on this and all of our workshops at https://ncmg.ucanr.org/ .
Ann Wright is a Nevada County Master Gardener