Every garden faces threats from insects and mammals. How you deal with them is important.
The Japanese beetle is currently public enemy number one. Long a problem on the East Coast and Midwest, it has finally invaded metro areas gardens after its initial accidental introduction to the Cherry Hills area.
A voracious eater, the Japanese beetle attacks many plants and is especially fond of grapes, cannas and roses. The damage on leaves can be spotted and diagnosed by its lacey appearance.
The beetle starts life as a grub in lawn turf. One method of control is to introduce counter measures into your lawn. Milky spore will make the grubs sick, beneficial nematodes act as parasites on the grub. The best control will happen when everyone with a lawn introduces milky spore and beneficial nematodes.
Once the full-grown beetles emerge, control includes hand-picking the beetles. They are black with an iridescent sheen and are about a third of an inch long. If you are quick, they can be snatched and dropped in a jar of soapy water.
If you decide to use pesticides, be extremely careful. You don't want to kill off beneficial insects such as bees. Neem oil can be used as a spray and doesn't have any detrimental effects to the environment. The chemical dusts Sevin and Eight provide some control as well.
The powder should be dusted only on leaves--not on flowers--since it can kill bees. The active ingredient in Sevin goes inert within four days so if it is used, it must be reapplied regularly.
In my garden, the fallback weapon of choice is soap. A teaspoon of Dr. Bronner's liquid soap in a quart bottle of water will kill many traditional pests such as white flies, aphids and spider mites. When the soapy spray hits them, the soap dissolves their hard exoskeletons and they literally melt away. Many of our grandmothers used this idea when they emptied their dishpans of soapy water on their vegetable plants in their gardens.
As for mammals that consume your plants, adequate fencing is the only reliable solution. Without that, gardeners use pepper sprays, coyote urine and other tactics to thwart deer, elk and rabbits. Researching what these animals generally prefer not to eat is also a smart move. As for squirrels, which many gardeners rail about, I feed them. I'd rather they eat some stale crackers or squash than to play havoc in the rest of the garden.