News from the Edible Demo Garden

September 2024: Tackling the Weeds

No matter what season, there is always weeding to be done in the Edible Demo Garden. Weeds seem to pop up everywhere – in and between the raised beds, in containers, and even in the straw bales. They are the uninvited guests among the cultivated organic fruits and vegetables.

What is a Weed?

The definition of a weed is tricky – more a value judgement rather than a plant category. Weed is a label given to a plant that is undesirable where it is growing. Any type of plant can be considered a weed if it turns up as an unwanted volunteer and competes with crops and landscape plants for water and nutrients or harbors viruses that can infect other plants.

Some plants such as purslane, which is considered by most to be a nasty weed, is also cultivated as an edible. Amaranth, a beautiful plant that has long been used for food by indigenous cultures, has a bad habit of showing up where it isn’t wanted. Even some popular native plants and wildflowers can get out of control and be considered “weedy”.

Although weeds are often described as invasive, the UC Integrated Pest Management Program considers invasive plants to be “a distinct group of weeds that occur in natural habitats”. They differ from common garden and agricultural weeds in that they are non-native and infest ecosystems causing damage to natural areas.

Annual vs Perennial Weeds

Annual weeds appear seasonally in summer or winter and are spread only by seeds. This makes a difference in how they can be controlled. The strategy is to get them out before they can go to seed. Common annual weeds include cheeseweed, crabgrass, purslane, and spurge.

Perennial weeds all have underground parts that enable them to spread through root systems as well as through seeds. These are the more stubborn weeds such as bermudagrass, field bindweed, dandelion, and yellow nutsedge. It takes some digging to completely remove perennial weeds.

Weed Management in the Edible Demo Garden

Only non-chemical methods for weed management can be used in the organic garden. Physically suppressing and removing weeds is a never-ending task for garden volunteers. It takes repeated efforts to reduce weed populations. Sheet composting and mulch are applied to suppress weeds between the garden beds. A weed-whacker has proven to be a handy tool for getting rid of annual weeds before they produce seeds. However, hand-pulling and digging remain the best methods for eliminating the most persistent of the pesky weeds. Some volunteers even claim to experience some “Zen” moments while weeding.

Read more about controlling weeds by clicking here.

Additional information can be found on the UC IPM website by clicking here.