None of the most problematic rodents here hibernate completely. Only ground squirrels hibernate, but they are rare, and tend to avoid home gardens and refined landscapes. Some other rodents are less active through the cooler parts of winter, but never completely stop eating, chewing and digging up what they want from our gardens. Many will become more active with warming weather.
Gophers are the most destructive rodents right now. They might still be excavating the mud of last winter from their tunnels. They will find plenty to eat as warming weather stimulates root growth of their favorite plants. Young gophers are growing up and leaving home, to excavate more tunnels and consume more vegetation elsewhere. They are more numerous now than they will be all year.
Squirrels are not so industrious. For now, they are destructive only if they dig out recently planted seedlings and bedding plants, or eat flowers and freshly emerging foliage. They should otherwise be temporarily satisfied with acorns that they hid late last year. They will become more of a problem as they eat ripening fruit, nuts and maybe vegetables later in summer. Some might chew bark.
Rats are sneakier than squirrels. They are not as destructive to ripening nuts and stone fruits, but do eat some of what falls to the ground. Although not a problem for the garden, well fed rats infest adjacent homes, where they cause serious damage. At this time of year, rats sometimes ruin citrus fruit. They eat the pulp out from the rinds of oranges and tangerines, and the rind off of lemons.
Rodents are nearly impossible to exclude completely and safely from gardens. Poisons are too dangerous to be practical around the home, particularly if there are dogs or cats anywhere nearby. Traps are safer and effective, but require diligence. Also, some traps are difficult to set. Each type of rodent exhibits distinct characteristics. That which controls one type is ineffective for another.
Sanitation and vegetation management deters some rodents by depriving them of sustenance and nesting sites.
Remember the Beverly Hillbillies? That was a really lame sitcom; but it was somehow very popular at the time.
Each episode began with the stupid jingle that explains how and why the formerly impoverished but suddenly wealthy Clampetts left their home in Bugtussle and moved to Beverly . . . Hills that is.
As they drive their decrepit Oldsmobile down Bedford Drive just west of downtown, the palms flanking the roadway are prominently visible to the left and right. This strictly regimented collection of Canary Island date palms alternating with Mexican palms was not very big back then, in the early 1960s. By the 1980s, they were strikingly grand. Sadly, they are now deteriorating from old age. Many of the broad Canary Island date palms have succumbed to pink rot, so are now absent. Some of the Mexican fan palms are also lacking. It is saddening to see them now knowing how grand they were not too long ago. Although they are being replaced, they will never be as formal and uniform as they were as a monoculture (or biculture) that was planted all at the same time back in the late Victorian period. Even if it were possible to remove all of the trees and plant new ones at the same time, such conformity went out of style decades ago.
Arborists see these historic trees differently. They know that just one Canary Island date palm is likely infested with rats. Such a grand collection must be infested with a disturbingly large population of rats. Within a canopy of a Canary Island date palm rats, are safe from most predators, and get quite a bit to eat from the fruit produced by the female trees. (Most Canary Island date palms are female, with only a few taller and less billowy male trees for pollination.)
When a Canary Island date palm gets cut down from the base, it falls with a big SPLAT on the ground, followed by a blast of wind containing every Frisbee, baseball, tennis ball, kite and whatever got stuck in the tree over the previous few years. After a brief pause, but before the the baseballs stop rolling in the gutters, a herd of all surviving rats flees the scene. Most hide in the closest shrubbery they find. Some scurry up other nearby palms. It can really blow your image of the Canary Island date palm.
Not much bothers old fashioned junipers. They tolerate heat and frost, and anything else the weather throws at them. They do not appeal to many troublesome insects. Once established, they do not mind if they do not get much water. So, aside from over-watering and bad pruning, they are pretty indestructible. Yet, once in a while, otherwise healthy junipers die suddenly and mysteriously.
Sometimes, entire plants die. Sometimes, only big pieces of them die. The foliage is intact, but dried to a nice light brown. The roots are firm. In fact, the damage that caused such efficient death might not become apparent until the dead stems get dismantled and removed. It might even get overlooked because it is not the sort of damage that we expect to find in our tame home gardens.
Rats! They sneak in under the dense foliage to chew the bark from the main stems. The thicket of rigid stems protects them from cats and dogs. They can kill both shrubby and ground cover junipers, as well as ivy, ceanothus, cotoneaster, firethorn, . . . and nearly any sort of shrubby plant that they feel safe from predators in. They also eat vegetables and fruits, particularly citrus fruits.
The damage should be rather distinct. Bark is missing. Bare wood is exposed. Squirrels sometimes cause the same sort of damage, but usually on smaller stems in trees. Gophers do their dirty work underground by eating roots. If they kill junipers or other shrubbery, the dead plants can be pulled up from the soil relatively easily, and fresh gopher ‘volcanoes’ should be evident in the area.
Protecting stems and roots from rodents is more difficult than protecting developing fruit. The rodents know that they are concealed by the dense growth that they chew the bark or roots from, so fake owls are not much of a threat. Poisons are very unpleasant for the targeted rodents (duh!), and very dangerous to cats and dogs that might catch the poisoned rodents. Traps are effective and safe (except for the rodents . . . duh!) but take serious dedication to empty and reset!