Weeds can be a real nuisance in gardens and landscapes, and even during the colder winter months, some kinds of weeds continue to grow and thrive. These are called winter annual weeds.
Most weeds are classified as annuals, biennials, or perennials. Annuals complete their life cycle (germinate from seed, grow, flower, set seed, and die) in one year or less, biennials generally complete their life cycle in 2 years, and perennials live longer than 2 years.
Examples of winter annual weeds include chickweed, little mallow, and annual bluegrass. They germinate and actively grow during fall and winter, then produce seed and die by the hot summer months.
If allowed to set seed, annual winter weeds can continue to grow...
Summer is a great time for outdoor activities like camping, hiking, and backpacking. During your adventures in natural areas, be on the lookout for poison oak. Poison oak, a well known plant for most people in California, is widespread in our state and can be encountered in open woodland areas, grassy hillsides, coniferous forests, and open chaparral.
Poison oak looks different depending on the time of year, and may be difficult to recognize. In spring, it has young leaves that are green or sometimes light red, along with small, white-green flowers. In late spring and summer, poison oak foliage is glossy green. As we head into late summer and early fall, the leaves will turn shades of orange and red with whitish-green,...
- Author: Cheryl A. Wilen
[From the UC Weed Science blog]
In what has been dubbed “dandelion-gate,” members of the Washington State legislature spent 20 minutes complaining about weeds on the capital's lawn. “In all the years I've been here I've never seen so many dandelions all over,” Sen. Mike Padden (R) said. “Is it your policy not to treat dandelions?” The department responsible for landscaping responded that the legislature cut its budget and now it only has 15 people covering the nearly 500 acre campus.
Catchweed bedstraw. It's that weed that tugs at your clothes while you pass by or attaches to your dog or cat's fur. It's also known as the “Velcro plant” since it easily clings to anything that touches it.
In the garden, catchweed bedstraw competes with landscape plants for nutrients, water and light. Once mature, it can reach 6 feet long and be problematic when it smothers desirable plants. It can also make it difficult for gardeners to harvest produce.
Catchweed bedstraw is a winter or summer annual in California. The best control is to physically remove it as soon as it appears so it does not spread. For tips on how to manage this weed in your landscape, please visit the
Invasive plants are weeds that infest natural ecosystems, rangelands and pasture. They can cause dramatic ecological changes that affect both plant and animal communities. Once established, invasive plants are difficult to eradicate.
In California, exotic plants were originally introduced by humans who planned to use them for ornamental or aquarium use, or for use as forage, food, fiber, medicinal or soil stabilization purposes. In some cases, the unintended outcome has been plants that have become invasive.
Some invasive plants are still for sale at retail nursery and garden centers. Some examples of available invasive plant species include pampasgrass (