What is a Weed?

The definition of a weed is “any plant that is unwanted or out of place in your garden landscape.” Weeds compete against cultivated plants for nutrients in the soil, as well as water and sunlight. In an urban landscape, weeds are considered unsightly and can create a place for insects and disease to proliferate.

Weeds are typically grouped into 2 categories based on their plant structure:

  • Broadleaf weeds usually have flat leaves, a network of veins, and grow by means of a taproot or coarse root system. When they first germinate, two leaves emerge from the seed.
  • Grassy weeds grow narrow, upright leaves and have parallel veins. They sprout only one leaf from the seed pod and develop a finer, more fibrous root structures.

Weeds are also classified by their life cycle.

Just like flowers and other plants, they can be annual, biennial or perennial.

  • Annuals complete their life cycle within one year or less
  • Biennials take two years to germinate, bloom and die. They are the least common type of weed, and will germinate in any growing season.
  • Perennials live at least two years, and have the potential to reproduce indefinitely. If their root system is not entirely removed they’ll continue to grow back again and again.

Why are weeds an ongoing problem in urban landscapes?
Weeds are genetically designed to germinate, grow and propagate faster than most cultivated plants. They are essentially adapted to spread. They can easily be distributed by animals, insects, topsoil and mulch. Unfortunately once weeds set root into your lawn or garden beds, they can remain there for a long time if not controlled properly. While most weed seeds only exist in the soil a few years, there is a small percentage that can remain dormant for decades, waiting for the right growing conditions to occur. To top it all off, most plants only produce a few hundred seeds, but weeds are especially prolific seed producers. One single weed can produce anywhere from 10,000 to over 100,000 seeds. It’s clear to see that if left untreated, weeds can rapidly take over a garden or lawn.