Flowers Faring Well From Fall Rain
According to the calendar, spring began a couple of weeks ago, but for gardeners, winter departed way back in January when the rain stopped. That’s when we had to start watering again, after a too-brief winter vacation.
Gentle rains fell all fall and partway into winter. Until February, we gardeners had happy faces and water in the bank, but now it looks like we’ll finish up with below-normal rainfall for the season. The time for a March miracle has come and gone.
All that autumn rain, however, followed by dry warmth, made a lot of plants extremely happy. No rain fell on this spring’s petals.
Along state highways and interstates, lupines bloomed from San Diego to San Luis Obispo; every major road I traveled was lined with the blue spires of lupine. Most were planted by Caltrans as part of erosion control mixes in years past, and the rains were spaced just right to bring them up in abundance. There were even fields of lupine beside Interstate 10 in urban West Los Angeles. Who knows how long the hard, pebble-like seeds had laid there waiting?
The new San Joaquin Hills tollway, which unfortunately cut across some precious wilderness between Newport Beach and San Juan Capistrano, was ablaze with acres of goldfields, one of our brighter wildflowers. Planted as mitigation by the builder of the tollway, there were also yellow poppies, miniature lupine, baby blue eyes, owl’s clover and strips of native perennial grasses.
They made it one of the best rides in Southern California for a flower fancier, better than anything at Magic Mountain, and a whole lot cheaper since it costs only $2 to ride its length.
A Special Spring
In gardens, azaleas of all kinds have been glorious the last few weeks. Even azaleas pruned into severe little hedges were covered with flowers. The saucer and other deciduous magnolias were a knockout in late December and January. Camellias also had a good year.
Several people called to exclaim over the various flowering Prunus species, including flowering cherries such as the Taiwan, or the variety ‘Pink Cloud.’ Flowering peaches and nectarines put on quite a show, and even the plebeian purple-leafed plum was anything but common this year.
Other flowering plums, such as Prunus blireana--usually happier in the northern half of the state--were spectacular, as were the varieties ‘Thundercloud’ and ‘Krauter Vesuvius.’ Before you run to the nearest nursery to buy one of these flowering fruit trees, check the Sunset Western Garden Book to make sure it will thrive where you live in a normal year.
Right now the roses are blooming. My wife came in the house last weekend with an armful of the new striped rose named ‘Scentimental,’ exclaiming about it being “a flower factory.” Put in a big vase on the dining table, they looked like a bouquet of peppermint candies, with deep red stripes and swirls on candy-white petals. Breathtaking.
They don’t smell like peppermint candies, but are powerfully fragrant with a spicy rose scent. This 1997 rose, developed here in Southern California by Tom Carruth, may become the most popular rose of the decade, especially for cutting. Be careful of the thorns, though; this one is particularly prickly.
Pest Parade
A parade of garden pests seems to be enjoying all this dry weather as well. I’ve never seen so many aphids on cabbages and other cole crops maturing in my vegetable garden. Roses, of course, were covered.
Spraying with safe insecticidal soap washes the aphids off and kills the hangers-on, but I’ve had to follow up with second, even third sprayings because they bounce right back, though now it looks like the ladybug larvae are getting the upper hand, so its time to quit.
I’ve already spotted some holes made by rose slugs (actually sawfly larvae), which means it’s time to spray with a light horticultural oil (such as SunSpray) and then follow that up with another a week or two later, before they do serious cosmetic damage. Last year, I missed this early spring opportunity, and my roses looked like they had taken a broadside of buckshot.
Horticultural oils are not poisons, but they do suffocate pests. Still, you can’t use any spray with impunity, so read the labels carefully on oil sprays and soap sprays. Days, for instance, can be too hot to use either.
Neem Oil
You may want to really study the label on a bottle of neem oil, a newish botanical pesticide that not only does in pests but seems to work on some tough diseases, though it has a very low toxicity to people, pets and other animal life in the garden.
Rose gardeners in particular are pretty excited about this oil made from the Indian neem tree (Azadirachta indica).
There are two neem products on the market; one is the oil and the other is a refined compound, but it is the less-expensive neem oil that is said to work as a fungicide as well as a pest control.
Rose growers report that it works on powdery mildew, which so far doesn’t seem to be a big problem during this dry spring, as well as rust and black spot. One neem oil product is named Rose Defense, made by Green Light Co.
The refined compounds--the active ingredient is Azadirachtin--don’t have fungicidal properties but are very effective against a great many pests. Azadirachtin is not a poison but a growth regulator that takes a few days to work, preventing insects from molting. It does not affect adult insects.
It’s been used on cutworms and cabbage loopers, some whiteflies and thrips, even fungus gnats. One brand is sold as Azatin, and another is Safers BioNeem.
Giant Whitefly Arrives
When I last wrote about the giant whitefly, which was expanding its range from Central America and Mexico into California, it was only in San Diego and south Orange County. Now a reader has called from near the Wilshire Country Club in Los Angeles, asking what all the white beard-like filaments are on her hibiscus.
There’s no mistaking an infestation. Leaves are dripping with white filaments and the undersides are covered with a white waxy substance. Look closely and you’ll see the whiteflies, which despite being called “giant” are still quite small, with a wingspan of about a fifth of an inch.
Touch the plants and clouds of whiteflies take flight, though it is the flightless larvae that do all the damage.
Hibiscus are a favorite food. So are avocados, citrus and a variety of ornamental plants from bird of paradise to xylosma.
The University of California has found a wasp that it is hoped will control this whitefly eventually but in the meantime there are some environmentally friendly sprays that can help.
Repeated soap sprays (such as Safers or Jungle Rain) seem to work, as do light horticultural oils (such as SunSpray). The botanical neem sprays mentioned above are also effective.
Thoroughly coat the undersides of leaves and spray about once a week for several weeks. Giant white flies are much easier to control at this cooler time of the year, so act soon if they’ve arrived in your neighborhood.
