Q: A few columns back, you recommended owls to control the rodent population. Would you please share your ideas on how to attract owls to an urban neighborhood?
We’ve found that if we wash and wax one of our cars and park it underneath the streetlight in front of our house, the resident great horned owl will, without fail, show up and hang out on the light. We learned that owls are very messy eaters, and when they poop, it’s “go big or go home.”
In all seriousness, though, the best way to show your local owls some love is to refrain from using any kind of poison. Even the supposedly “safer” rodenticides containing warfarin and chlorofacinone are harmful to non-target wildlife, including owls. Rodenticides containing brodicfacoum, bromadiolone, difenacoum, and/or difethialone have been greatly restricted due to their devastating effects on predators and scavengers. If you have any of these on hand, please dispose of them at a hazardous waste disposal site.
I recommend battery-powered electrocution devices for rodent extermination since they are clean, environmentally friendly, and humane. These are most effective where rodents have invaded indoor spaces, especially since you don’t have to worry about a poisoned rat dying in an inaccessible spot. The animal dies instantly, and all you have to do is shake it out of the trap. Snap traps are less expensive, but getting the dead rodent out of the trap can be kind of tricky (and icky).
Clearing away potential hiding places for outdoor rodents makes hunting a bit easier for owls, hawks, and other predators. Even when you don’t have the space for an owl box, you can help these beautiful creatures.
Q: My summer vegetable garden started off strong, but now all the leaves are covered with a white powdery substance that doesn’t rub off. The leaves are starting to curl up and dry out, even though I’m watering every day. What is causing this?
Powdery mildew is a fungal disease that occurs in dry climates. Curcurbits (squash, pumpkin, and cucumber) are most susceptible, but it can affect other crops as well. Once a plant is infected, it will decline and die. There is no remedy – the affected plants should be disposed of in the regular trash (never compost diseased or heavily insect-infested plants).
Poor air circulation contributes to the problem. When planning your garden, allow for plenty of space between plants. If powdery mildew is a frequent problem, periodic spraying with an antifungal agent (Daconil) can prevent recurrence. Daconil is only effective at preventing mildew, so treatment should start before symptoms appear. Be sure to thoroughly coat the leaves when spraying. Vining plants can be grown on a trellis to make this task somewhat easier.
Los Angeles County
mglosangeleshelpline@ucdavis.edu; 626-586-1988; http://celosangeles.ucanr.edu/UC_Master_Gardener_Program/
Orange County
ucceocmghotline@ucanr.edu; http://mgorange.ucanr.edu/
Riverside County
anrmgriverside@ucanr.edu; 951-955-0170; https://ucanr.edu/sites/RiversideMG/
San Bernardino County
mgsanbern@ucanr.edu; 909-387-2182; http://mgsb.ucanr.edu