- Author: Chris McDonald
As the summer heat is finally nearing its end, and its officially fall on the calendar, there unfortunately is a new crop of weeds flowering right now. Some of our summer annuls have started to go to seed, others are just about ready, and others are already starting to senesce. In order to manage these weeds, managers must stop the plants from reproducing. With our summer annuals that means stopping the plants from producing seeds, right about now, (or maybe three weeks ago).
However, treating a giant tumbleweed right now isn't really my favorite activity. I'd rather spend my time treating small tumbleweeds and working more effectively and also using less labor and/or herbicides to do it in the process....
- Author: Chris McDonald
I'm sure you've noticed that different years have dominant weed species. For example this year in Southern California Russian thistle (aka tumbleweed Salsola tragus among other Salsola species) is abundant in many areas. Other years it is only moderately abundant and some years it seems to hardly hang on. The obvious question is why? Why is there so much variation in abundance between years?
Fortunately for us people have been working on this issue for a while and have a few general answers for us. Since the bulk of weeds in California are annuals I'll limit my discussion to those plants.
The seeds of annuals germinate only under a certain range of environmental conditions....