Media frenzies and
From the Davis Enterprise, March 22, 2007
Musings in early spring ...
A couple of stories from the popular press have caused comments and questions to come our way.
"I'd better get these things planted early; I've heard it's going to be a really hot summer this year."
Tracking this back, I found a January report from the University of East Anglia (UK) as the early source of this rumor. Based on computer models incorporating global temperature trends and the impact of El Niño, climatologists there stated they believed there was a 60% chance that this year's worldwide temperatures could match or exceed the records set in 1998 (previous record: 1934). Reporters then interviewed some researchers here who, at least as quoted, mostly just confirmed the global temperature trends. This didn't stop the breathless headlines. My favorite: California Steamin':
Forecasters Predict Hellacious Summer, World's Hottest Year on Record! (DailyNews.com).
It is true that El Niño has been correlated with higher summer temperatures in the west of North America. But El Niño has fizzled. By February, the ocean temperature data showed --no anomaly -- that is, no warming -- and in fact we appear to be heading into La Niña (cooling) pattern of ocean temperatures. North American summer temperatures during La Niña events have generally been near average. So a major component of that January prediction no longer holds.
In fact, the National Weather Service Climate Prediction Center (www.cpc.ncep.noaa.gov) issued regional forecasts on March 15. Their outlook? An equal chance of temperatures being above or below normal for most of North America. Exceptions: Arizona, southern Texas, southern Florida, the Great Lakes, and New England are likely to be warmer than the 30-year average.
What does this mean for gardeners? It will, undoubtedly, be a hot summer here in the Sacramento Valley--it usually is! Expect a couple of dozen days with high temperatures over 100 degrees, a couple of dozen in the 80's, and the rest likely in the 90's. Expect the delta breeze to make it livable most of the time, and a couple of real hot spells in July. That would be normal.
"But you can plant any time the soil is workable here."
The key is the after-care you give the plants, especially proper watering. The most important factors in plant success, regardless of the time of year you plant them, are
Choosing the right plant for the situation and for this area.
Digging a proper planting hole.
Watering correctly and carefully during the weeks after you plant.
"Where are all the bees? I hear there's a new disease killing them all."
There have been several stories about bee problems in the last few weeks. Item: Honey production fell 23% in the nation's top beekeeping state (guess which state ranks #1 in honey production? Answer below!) and fell 34% in California, which ranks #2. Dry weather in the Midwest, and mid-summer heat waves there and here, were blamed.
Item: Growers' costs are up. European honeybees have been beset by Varroa and tracheal mites since the 1980's. 'Wild' (feral) hives of European honeybees are mostly gone. Increased management expenses for beekeepers have been passed along to almond growers, with colonies costing over $135 each this year (2004: $55).
The most recent publicity is about Colony Collapse Disorder.Ê Some beekeepers in some states are opening their bee boxes and finding no adult bees. The capped brood are present, there is pollen and honey, but the queen and all the adult bees are gone. Not dead, just decamped. This is not entirely new: there have been reports going back over a hundred years. But in late 2006 the loss rate reportedly reached unusually high levels. Possible causes, including stress, pathogens, parasites, nutrition, and heredity, are being explored by a working group at Penn State.
We have had calls for several years about lack of pollination on early summer crops such as melons and squash. There are plenty of bees in the area in the spring, as local almond and fruit growers import hundreds of hives that remain active here through the spring bloom period. But many of those hives are trucked north by early summer, and the loss of the 'wild' honeybees has reduced the pollinators for your vegetables.
So imported bees will probably take care of your fruit trees. But if your zucchini doesn't seem to be setting, you may need to pluck the male flowers and take them to tickle the female flowers. They're easy to tell apart: the female flowers already have undeveloped, but visible, fruit at the base of the flower. Planting flowers that draw bees among your vegetables can be helpful. Try Borage, Cosmos, and Sweet alyssum. All are easy from seed and tend to reseed themselves (to put it mildly) for subsequent years.
You may be fortunate enough to have an amateur beekeeper in your neighborhood, and they don't have to be right next door. How far do bees fly? The flip answer is as far as they have to.Ê In a classic study published in 1933, it was shown that honeybees would fly as much as 7 miles! They also exhibit strong preferences for some flowers more than others. We do have native bees of various types, though they tend to be less efficient pollinators.
Speaking of bugs, we get questions as lots of critters emerge in the spring ...
"Why are we still getting aphids on our hackberries?
Haven't natural predator populations increased to take care of them?"
You will see lots of ladybugs, lacewing larva, syrphid flies, and other aphid-eating beneficial insects on your hackberry tree, feasting on the Asian woolly hackberry aphid that arrived in 2002. But they can't reproduce anywhere near as fast as the aphid. Biological control programs usually focus on introducing a predator that is specific to the pest, which can be reared readily and which reproduces rapidly. No naturally occurring beneficial insects in our area meet that job description. So for now the most effective management is imidacloprid (Merit), a systemic applied in the spring. Or you can just live with the incredibly sticky mess all over everything. Even very heavy aphid populations don't seem to stress the hackberries, though they definitely stress the homeowners.
"So, can I release ladybugs in my garden?"
Sure. On a cool, overcast day ladybird beetles will stick around. On a hot sunny day they will tend to fly away. In either case, release them in the evening and they will eat a lot of aphids before they go. Put them at the base of infested plants, and then cover those with seedling blankets (floating row cover) for a few days, and they will eat even more aphids. If you have a diversity of plants in your garden, including ornamental grasses and herbaceous perennials, they may settle in.
Note: you could not release enough ladybugs to control your hackberry aphids, at least not at a reasonable cost.
"What about praying mantids?"
They're fun, they're interesting to watch, but being general feeders they eat everything -- including other beneficial insects and each other. So of the hundreds that tumble out of an egg case in the spring, only a few remain by season's end. But if your garden has suitable habitat, they will lay eggs and show up in future years as well.
Don't panic about a sudden increase in pests. In most cases the problem will run its course, and safe solutions are available. Learning to recognize the good guys is an important first step!
The #1 honey-producing state is (drumroll, please) -- North Dakota! Their official state beverage is milk. So I guess North Dakota is the land of milk and honey.
© 2008 Don Shor, Redwood Barn Nursery, Inc., 1607 Fifth Street, Davis, Ca 95616
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