Today was cooler but still hot. Am trimming the yew hedge and making an archway. Hopefully in a few decades it will look like the hedges at Great Dixter!
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A sweltering day with the temperature hitting 90. I’ve finally taken the last languishing 'house' plants outside and lined them up on the mudroom steps and soaked them under the hose. The only summer container plants that really survive my brutal care are the common geraniums, Pelargonium zonale. I wouldn’t say they thrive on winter neglect and the bone dry potting soil that surounds their roots on the backstairs windowsills, but they live to see another summer. They’re also the only plants that thrive in the summer under my (non) watering scheme. I’ve been tempted to ONLY plant geraniums in previous years -- partly inspired by the incredible window boxes and containers of geraniums we saw in the Alsace Lorraine a couple of years ago. This year I'm trying these pink and red trailing geraniums in hanging baskets on our garage pergola which is really to shady for them but the reflected heat from the asphalt driveway seems to fry shade loving annuals. Besides aesthetics, there is now a really compelling reason to fill the garden with common geraniums. Scientists have known since the 1920s that geranium flowers appear to both attract Japanese beetles and paralyze them -- the beetles become so intoxicated by the petals they pass out for 12 to 18 hours which in the wild can be a lethal binge. Recently UK entomologists Daniel Potter and David Held have studied this phenomenon further to discover what causes this reaction. Japanese beetles are the scourge of home gardeners and retailers -- eating over 300 types of plants and 79 plant families. Almost all of the states east of the Mississippi River except Florida suffer incredible financial damage from greedy beetles, and the U.S. Department of Agriculture is keen to prevent the beetles spreading to the western US where they could devastate California vineyards and crops. An effective and earth-friendly way of exterminating Japanese beetles would be a goldmine and the geranium’s knockout punch seems to have great potential. "We found that when Japanese beetles fed upon the petals of geranium, generally in less than an hour the bugs enter a kind of narcotic state," says Potter. "They curl up on their back and pull their legs close to their underside. They'll twitch if you disturb them, but they're clearly in dreamland." Funded by the USDA, Potter and Held have found that the bugs seem unable to resist geranium temptation -- when beetles were given a choice between nutritious linden plants and mind-blowing geraniums they overwhelmingly went for the geraniums and ended up on their backs. Nor did they learn from their mistake, every time they recovered from their geranium-trip they ignored the healthy choices and chomped down on almost 10 times the previous amount of geranium petals before becoming intoxicated again. Interestingly, geraniums grown in full sunlight packed more of a gastronomic punch for the beetles. Potter's team also reared pairs of beetles in boxes with soil so that they could lay their eggs while they observed the beetles. One group received the healthy linden leaves, one group received the geranium petals, and one group received an equal amount of both. "As one would expect, the group that got the linden leaves lived long and happy lives and laid a large number of eggs," says Potter. "Both groups with access to geranium spent the better part of this two-week experiment on their backs in a narcotic state, had a much higher mortality rate, and laid very few eggs." With the help of plant chemists at Cornell, UK researchers are testing various geranium chemicals on the beetle-favorite Virginia creeper, and they've been able to duplicate the geranium's narcotic effects. Potter says that by this coming summer they'll have identified the exact extract which should be invaluable in creating effective Japanese controls. "One of my goals is to understand the insect better," says Potter. "I think if you understand the biology of a pest insect, it opens up new avenues for management that are environmentally more responsible." The Japanese beetle's behavior makes it an interesting insect to study, Potter says. "I really like the Japanese beetle. It's my bread and butter insect. It's a great bug, sort of The Terminator of the insect world." Maybe this summer I actually will create an Alsace inspired geranium display and sit back with a glass of Riesling to watch the beetle show. Our local beekeepers are still very concerned about the so-called "colony collapse disorder" CDC in which seemingly healthy bees simply vanish from the hive, leaving the Queen and a few newly hatched adults behind. They claim they are still losing between 30% - 90% of their hives each year. Billions of honeybees have died in the US since CCD became apparent in the winter of 2006-2007. Honeybees are used to pollinate more than 130 crops in the US worth over $15 billion, and teams of scientists have been working to solve their mysterious disappearance. There are still many theories floating around, and the beekeepers I've spoken to have different strategies for establishing successful hives. An organic keeper I spoke to months ago recommended a minimum of 6 hives, and said most beekeepers feed sugar in the fall which is completely wrong. Our beekeeper thinks current research points to having less than 5 hives to mimic natural habitat more closely and try and keep mite populations in check and said feeding sugar water in the fall might be necessary if we have a terrible summer and there are not that many natives flowering as they might need the extra food to sustain them through another potentially bad winter. I can see the sense in this, though am hoping the summer is terrific and all our autumn flowering wild grasses and natives make sugar water unnecessary. An early study published in the journal Science in 2007 showed a strong correlation between CDC and a pathogen called Israeli acute paralysis virus, or IAPV. Scientists screened honeybees collected from colonies infected with CCD with honeybees from healthy hives and found the IAPV virus, which is transmitted by the varroa mite, in all samples from the CCD colonies. Jeffrey Pettis, an entomologist at the USDA's Agricultural Research Service stressed this was only a strong correlation, not a proven cause-and-effect connection and the research did not prove that IAPV was actually the cause of CCD. A recent study conducted by researchers at Washington State University posits a combination of toxic chemicals and pathogens are probably to blame. "One of the first things we looked at was the pesticide levels in the wax of older honeycombs," researcher Steve Sheppard said. The researchers acquired used hives from the U.S. Department of Agriculture, finding that they had "fairly high levels of pesticide residue." When bees were raised in these hives, they had "significantly reduced longevity," the researchers said. Prior research by scientists from Pennsylvania State University found unprecedentedly high levels of two pesticides in every sample of honeycomb or foundation wax tested, as well as lower levels of 70 other pesticides. The pesticides found in the highest concentrations were fluvalinate and coumaphos, used to eradicate the bee pest varroa mites, which have themselves been suggested as a cause of colony collapse. "We do not know that these chemicals have anything to do with colony collapse disorder, but they are definitely stressors in the home and in the food sources," said Penn State researcher Maryann Frazier. "Pesticides alone have not shown they are the cause of [colony collapse disorder]. We believe that it is a combination of a variety of factors, possibly including mites, viruses and pesticides." The Washington State researchers uncovered another potential cause, which likely interacts with chemicals to contribute to colony collapse: the pathogen Nosema ceranae, which entered the United States around 1997 and has since spread to bee hives across the country. The pathogen attacks bees' ability to process food and makes them more susceptible to chemicals and other infections. "What it basically does is it causes bees to get immune-deficiency disorder," said beekeeper said Mark Pitcher of Babe's Honey. "So it's actually causing the bees to almost get a version of HIV." So far our new bee colonies seem to be alive and buzzing, with bees swarming over the nepeta and herbs in the garden and will be fat and healthy enough to be nursed thorough whatever the winter throws at us. |
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