"Advice is what we ask for when we already know the answer but wish we didn’t."
–Erica Jong
"Let us love nobly in marriage, and add again
Years and years unto years..."
– with apologies to John Donne
As a consequence of our on-and-off warm, humid and overcast weather,
I have been busy dispensing advice on pest and disease management, not only to Catharine, but to in-laws, neighbors, friends, and even clients. My patients are plants, routinely attacked and injured by a familiar gang of pests or diseases... but not always.
Seasoned gardeners recognize the usual problems riding roughshod in their garden. Powdery mildew, aphids, caterpillars and mites are expected this time of year. There are many tried and true control options available with varying degrees of efficacy (depending on your toleration of plant damage versus pesticide pollution). But what happens when something bad occurs in your garden and you don’t recognize the problem?
Identification is the key to proper management of plant pests and diseases. Many of the "problems" I see at first display symptoms similar to insect or disease damage. However, closer inspection often reveals that the damage is the result of either natural occurrences (i.e., extreme heat or cold) or unsound cultural practices (improper watering or location).
Environmental factors may even predispose a plant to be attacked by weakening its natural immune system. Before dusting off that old bottle of DDT or calling the Orkin Man, one should first ascertain what is really ailing your plant. It may be as simple as moving the plant around the corner. If you are uncertain of the problem, consider consulting your favorite nursery.
One thing I have learned over the years is that there is a nearly inexhaustible horde of pests and diseases waiting to invade our borders. They arrive primarily through natural migration and contaminated shipments of live plants and foodstuffs. That is the reason California has strict regulations governing the inspection of plant material into and within its boundaries.
Eugenia was once a popular plant in Laguna, useful for hedges and topiary, but the invasion of psyllids has curtailed its use at the present time. Infested leaves become curled, distorted and covered with blisterlike galls. Pesticides are rarely effective... consistent watering and fertilization to maintain a vigorous plant has been the best solution.
Although the seven years of drought are just a faint memory for some, it left its mark on the Monterey pine and eucalyptus population in the village and canyons. Both were stressed by lack of water and became susceptible to attack. The Ips engraver beetle became the nemesis of the Monterey Pine, while the Eucalyptus longhorned borer proved fatal to a number of eucalyptus trees. A program of supplemental watering and removal of diseased trees would have saved dozens of trees.
If you have hibiscus or bird of paradise growing in your garden, I strongly suggest you look at them closely. Giant whitefly has invaded Laguna in a big way. Not only are the adults huge (many times larger than whitefly) but they quickly multiply and create a trademark colony of white threads that hang from the undersides of infested plants. Washing the leaves constantly with a stream of water and applying horticultural oils and insecticidal soaps are the best line of defense.
Like the eugenia, the ubiquitous oleander may soon be departing nurseries and even the landscape. A relatively new insect, the glassy-wing sharpshooter leafhopper is infecting oleanders with a deadly bacterium. The foliage appears to have been burnt by a blowtorch... Oleander leaf scorch is unfortunately, an apt name. At this time, there is no remedy other than removing infected plants.
Today is my parent’s wedding anniversary. Forty-eight years and going strong! Happy Anniversary! Their marriage has been an inspiration to me... one of the reasons I decided that being married was possible. Of course, Catharine does make it easy to be Mr. Cooper. See you next time.
|
