Many parks, recreational areas, and outdoor venues in California are home to yellowjacket wasps (Vespula spp.). Yellowjackets are commonly attracted to human food items, creating a serious nuisance and a potential stinging threat. If found, nests (usually underground) can be effectively treated with targeted insecticide applications (e.g., dusts containing pyrethroids). However, baiting could be a feasible alternative method to suppress yellowjackets over a wide  area, especially if nests cannot be located. Currently, only one active ingredient (esfenvalerate) is registered for use within bait in California to control yellowjackets,...

Nutgrass, also called nutsedge, could easily be one of the top 5 nuisance weeds gardeners deal with in the garden and landscape. While we don't know that for sure, we do know that nutsedge is a very challenging weed to control.

Yellow and purple nutsedge are the two species most often found in California. Yellow nutsedge grows throughout the state, while purple nutsedge is found mostly in southern California.

Nutsedge is difficult to control because the plants form small underground tubers and rhizomes. Most of these tubers are found in the top six inches of the soil but can also be found even deeper. Removing the tubers by hand is the best way to remove small plants but may require continued monitoring and hand...

If you are seeing black and red bugs scurrying about near trees and buildings, they may be boxelder bugs. Boxelder bugs (Boisea rubrolineata) feed on the flowers, leaves and seedpods of female boxelder trees (Acer negundo) and occasionally are found on maple and ash, and sometimes on certain stone fruits and grapes.

Boxelder bugs are often confused with other insects that look similar such as red-shouldered bugs, squash bugs, the bordered plant bug, and leaffooted bugs.

This insect doesn't usually cause significant damage to landscape plants, but when their numbers are high during fall, they can build up on outside walls or sometimes enter houses and may be considered a nuisance.

If you have a...

Wet weather is favorable to mushrooms, which are sometimes called toadstools. Mushrooms are the visible reproductive (fruiting) structures of some types of fungi. Although the umbrella-shaped fruiting body is the most common and well known, mushrooms display a great variety of shapes, sizes, and colors. Some other fruiting bodies encountered in lawns include puffballs, stinkhorns, and bird's nests, descriptive names that reveal the diversity of forms among mushrooms. But regardless of shape, the purpose of all fruiting bodies is to house and then disseminate spores, the reproductive units of fungi.

Many people become concerned when mushrooms appear in their lawns; however, most mushroom-producing fungi in lawns are merely...