My Golden Gate Gardening column in today's SF Chronicle (www.sfgate.com) was about Nothoscordum gracile, a weed to watch out for in your garden. I thought I would put a few photos in this post, for those who wonder if they have it and to help you understand what is going on underground if you do have it. The plant, shown at left, has white flowers that look a little like a brodiaea. It blooms most actively in summer. The leaves are strap-like, gray green, and do not have a midrib. This plant is not edible and does not have any scent of onion or garlic. The plants can be easily overlooked, but the best way to control them is to remove the first one you see, digging carefully to get all of the root and the bulblets, even discarding a handful of soil to be sure you got rid of all the bulblets.
Here is a mature bulb with its many bulblets, each the size of a grain of rice. The youngest ones are white, so they stand out well against the soil, but the older ones turn brown, and are very difficult to see. The bulbs are usually very deep in the soil--as deep as your shovel can reach. Be sure your shovel blade is straight up and down when it enters the soil, or you may cut the stem of the plant, leaving the bulb unmolested in the soil.
The problem with leaving some of the bulblets in the soil is that they will all germinate into small plants. Incompletely digging a Nothoscordum bulb, and then turning the soil in the bed can spread the bulblets all over, so that soon you will practically have a lawn of the plants. I am combating this weed now in a vegetable garden, digging out mature bulbs and also digging the smaller plants carefully to be sure I have removed the attached bulbs, and am ruing the day I tolerated the first plant of it. Don't make the same mistake.