Part of my job as the Director/Farm Advisor at the Intermountain Research and Extension Center involves overseeing weed management programs for a variety of crops and non-cropland at the Center.  Over the last month, I’ve observed the outcome of these programs as many of the crops are nearing harvest.  This spring I would have given myself an “A” grade for weed control.  We treated crop fields with a combination of control methods and made an aggressive push to control weeds along roads, ditches, and field borders.  Unfortunately, as time goes on I think I need to downgrade my performance to a “B” because some fields and roadsides now have quite a few weeds.

In reviewing field records, one factor was a common denominator at...

Over the weekend, the Sacramento Bee published an article discussing the invasiveness and spread of yellow starthiste (Centaurea solstitialis) in California. http://www.sacbee.com/2011/08/21/3847369/invasive-yellow-star-thistle-aims.html

 It was written as an "interview" with the weed which, although a little cute for me, may help the general public understand a bit more about yellow starthistle which currently infests over 15 million acres of rangeland and noncrop areas of California.

For folks interested in more scientific information on yellow starthistle biology, ecology, and management in California and other...

I ran across a Weed Science Society of America (WSSA) press release from last summer that I found interesting. 

The article, entitled "The Deadly Problem of Poisonous Weeds", outlines ten poisonouos weeds in North America that are particularly dangerous and features information from UC Davis Cooperative Extension Weed Specialist Joe DiTomaso.

The article includes basic information on the toxicity, identification, and links to photos of::
1. Poioson hemlock
2. Waterhemlocks
3. Oleander
4. Bittersweet nightshade
5. Common pokeweed or pokeberry
6. Pennyroyal
7. Meadow...

The nursery industry has introduced thousands of ornamental plants, but only a small percentage (~1%) has escaped to become invasive and cause economic or ecological damage. Thus, the removal of these known invasives should not present a major economic hardship on the industry. In addition, a pre-screening of potential introductions would be expected to accept most species as possessing low invasive potential, and identify relatively few as having a high probability of becoming invasive.

Currently, several Weed Risk Assessment (WRA) models have been developed, the most common of which was developed by Paul Pheloung and his colleagues in Australia. This model is currently used to evaluate new introductions in other parts of the...

Field Bindweed (Convolvulus arvensis)

The late spring rains that fell in Northern California seemed to benefit some plants more than others. One weed that appears to be doing very well this year is Field bindweed.   Field bindweed (Convolvulus arvensis), is a perennial weed that spreads by seed, creeping roots and rhizomes. You may call it morningglory or wire weed. It has arrow-shaped leaves and white to pink trumpet-shaped flowers and can grow spread along the ground from early spring until late fall. Bindweed’s creeping roots can penetrate the soil to more than 10 feet and send up vertical shoots that look much like seedlings, but unlike seedlings, are part of a much larger plant. Studies...