DEAR JOAN — Is there a way to prevent the black mold that shows up on hummingbird feeders?
I clean the feeder every time I fill it, but the mold persists.
Rada Ford, Mountain View, California
DEAR RADA: Mold can be an unfortunate byproduct of the sweet nectar we feed hummingbirds. It can be worse in the summer when high temperatures may make the nectar spoil and encourage mold growth.
To reduce the chances of mold, make sure you're not giving the hummers nectar that is too sweet. The recommended formula is 4 parts water to 1 part plain, white sugar.
On hot days, try hanging the feeder in the shade and keep an eye on the solution. If it starts to turn cloudy, replace it immediately. When temperatures are regularly above 90 degrees, you should change the nectar every couple of days.
If you're having a recurring issue with mold, make sure you clean the feeders thoroughly. That means soaking them in a mild solution of bleach or cleaning them with vinegar. Try soaking them in your preferred cleaning solution for an hour, then rinse them well. It's a good idea to let the feeder dry completely before refilling it.
You might also want to invest in a stiff bottle brush to clean all the parts of the feeder, including the feeding tubes and flowers. Stores that specialize in wild birds will have special brushes for just this chore.
Mold can sicken the hummers, so it's imperative that you keep the feeders as clean as you can.
DEAR JOAN: We have a 5-year-old miniature poodle who loves people when we walk, but will bark and get aggressive when we meet other dogs while walking.