Nature’s Fireworks

July 11, 2011 under CANR News

 Annelid worms do it. Certain species of centipedes and millipedes do it. Even a tropical land snail can do it.

But here in Delaware, fireflies and glow worms are the only terrestrial creatures that light up the night with their own built-in flashlights.

Bioluminescence results from a chemical reaction in which chemical energy is converted to light energy, according to Doug Tallamy, chair of the University of Delaware’s Department of Entomology and Wildlife Ecology in the College of Agriculture and Natural Resources.

Fireflies (Lampyridae) aren’t actually flies and glow worms (Phengodidae) aren’t really worms. Both are considered to be beetles and are closely related species.

The fireflies’ glow adds beauty to a summer night but there are several pragmatic reasons for bioluminescence, too. Fireflies and glow worms light up to attract the opposite sex. Adult fireflies, both male and female, flash coded messages to attract prospective mates. Males fly about while they flash, females usually flash while hanging out in bushes. It’s all about “speed dating” not lengthy courtships — there’s no time to waste since adulthood only lasts for about two weeks.

There’s another reason why fireflies light up, at least in the case of juvenile larvae. Almost a decade ago, UD scientists led by Tallamy discovered that baby fireflies light up to keep predators at bay.

Previous studies had shown that mice and other would-be predators shun adult fireflies because of a compound in fireflies’ body that produced a bitter taste. The UD study demonstrated that baby fireflies flash to advertise that they also exhibit this bitter taste.

“A flashing neon sign may lure hungry humans to an all-night diner but the bioluminescence of firefly larvae sends a very different message to would-be predators,” says Tallamy.

Summer season

This summer is shaping up to be a good but not spectacular season for fireflies.

“Lightning bug populations at my house have been strong but not record-breaking,” says Tallamy. “In general, populations fluctuate from habitat availability more than from weather. However, if we get a bad drought during the summer and fall that does impact the population of lightening bugs the following summer.”

Fresh strawberries for a few short weeks around Memorial Day. Carnival rides at the State Fair for 10 days in July. Like other summertime pleasures, firefly season is short-lived.  “Nature’s fireworks” begin a few weeks before July 4th and are at their peak now. By the end of July they’re gone, save for a few stragglers.

Where to find different species

Several species of fireflies can call themselves native Delawareans. The beach region of Sussex is home to the coastal firefly, which prefers sandy, even salty, soil and generally stays close to the ground. Inland Sussex and Kent counties are home to yet another species. But the greatest diversity in firefly species is found north of the Chesapeake and Delaware Canal, says Tallamy.

“Fireflies are especially abundant in the Piedmont region, in the northernmost part of Delaware,” he says. “Most firefly species favor ‘old field habitat.’ In New Castle County, that type of habitat is most commonly found around the White Clay and Red Clay creeks and along the Brandywine River.”

At first glance, one species of firefly may not look much different from another. But pay close attention to fireflies as they begin to light up. “If you look closely, you’ll start to notice some distinct variations in their flash pattern,” says Tallamy.

There are three characteristics that differentiate firefly species:

  • Where the fireflies are located. Some species like to be close to the ground; others prefer shrubs and low trees.
  • The flight track, or style of flying, varies from species to species. Some fly in a “J” pattern then swoop down low, others take looping flights.
  • The pattern of the bug’s flashing. Think of the flashes like Morse Code — do they resemble a dash-dash-dash pattern or dash-dot-dash?

If your kids like to catch fireflies and put them in a jar, go for it, says Tallamy, as long as you punch some holes in the lid and release the fireflies after a few hours. Fireflies are beneficial insects; in their larval form they feed on garden and crop pests.

Article by Margo McDonough

The article can also be viewed online on UDaily.

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Happy National Pollinator Week

June 21, 2011 under CANR News

Debbie Delaney looked like she was feeling the heat on a recent 95-degree day at the University of Delaware apiary, despite the shade of black walnut and tulip poplar trees. It was hard to tell how the 22 hives of honeybees – some two million bees in all – were handling the steamy weather.

But Delaney, an assistant professor of entomology and wildlife ecology in the College of Agricultural and Natural Resources, had no worries. “Bees are much better at thermoregulation than humans are,” says Delaney. “Honeybees maintain strict temperature control. The colony always stays between 89 and 92 degrees, ideal for a honeybee, and the humidity never varies more than 5 percent. Worker bees flap their wings to cool the air and some periodically leave the hive to reduce the effects of body heat.”

Delaney has been researching bees for years but continues to be amazed at their abilities, including staying comfortable in the heat while we wilt. She’d like to see bees get a bit more respect — if not the all-out enthusiasm she displays.

She’ll have an opportunity to spread the word about bees this week, which marks National Pollinator Week. The event recognizes not only bees but all pollinators – birds, butterflies, bats and beetles. One in every three bites of food humans consume has been made possible by one of these pollinators.

Pollinator Partnership, a nonprofit organization that sponsors the week, calls bees the primary pollinator of most plants. Delaney agrees, with a slight qualification.

“Bees are definitely the most important pollinator in our state in terms of the numbers and the importance of the crops they pollinate,” she says. “But bats also are important in a different way. Bat-pollinated flowers generally open at night and have distinct floral tube sizes and shapes that can accommodate bats.  So bats are very important pollinators for a certain subset of plants.”

Even while giving bats their due, Delaney rattles off the Delaware crops that bees do pollinate: apples, asparagus, blueberries, broccoli, cabbage, carrots, cantaloupe, cucumber, eggplant, honeydew melon, nectarines, peaches, pears, peppers, pumpkins, okra, onion, squash, strawberries, tomatoes and watermelon. She’s quite sure she has missed a few. After all, bees pollinate more than 90 crops in North America.

Non-native honeybees are responsible for some of this pollination. But Delaware’s native bees deserve credit, too.

There are at least 200 native bees in the state, according to the state Department of Agriculture, which recently completed a five-year study of native bees. “Recent research has shown that native bees can play a major role in pollinating agricultural crops,” notes Delaney. “Native bees often will visit flowers in wet or cold weather when honeybees don’t want to come out of their hives. And farmers who use managed honeybees will see increased yields when native bees interact with the crops.”

Wild honeybees – descendants of honeybees introduced by European colonists – also play a role in agricultural pollination. Research on these feral bees may even help combat colony collapse disorder, a poorly understood syndrome that can wipe out entire hives of managed honeybees.

The Feral Bee Project, sponsored by North Carolina State University, asks beekeepers and “citizen scientists” to log the location of wild honeybee hives at the Save the Hives website.

“Colony collapse disorder in domestic honeybees continues to be a major concern,” says Delaney. “We still don’t know the cause or causes of this syndrome. But the Feral Bee Project may give us a better understanding of the role that natural resistance plays in fighting disease or environmental stress, as well as a better understanding of genetic components that contribute to ‘survivor stock.’”

Learn more

To find out more about pollinators and National Pollinator Week, go to the Pollinator Partnership website.

The Brandywine Zoo will be hosting “Pollinator Power” on June 25, a family friendly event from 10 a.m. to 4 p.m.

Article by Margo McDonough

Photos by Danielle Quigley

This article can also be viewed online on UDaily by clicking here.

 

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Create a backyard rain garden

May 24, 2011 under CANR News, Cooperative Extension

Want to do your part to help local rivers and bays? Create a backyard rain garden.

It’s fairly easy to build your own rain garden and it can pay big dividends for nearby watersheds.

Stormwater runoff is one of the leading sources of pollution in waterways, according to Valann Budischak, a horticultural associate with University of Delaware Cooperative Extension. But rain gardens can be a great way to manage stormwater. Rain gardens are shallow depressions, planted with perennials and woody plants, which collect water from roofs, driveways, other impervious surfaces and turf grass (which, like a driveway, is lousy at absorbing water).

Rain gardens slow down and reduce runoff and thus help prevent flooding and erosion. In addition, the garden’s soil and plants filter pollutants in rainwater.

“Rain Gardens for the Bays” was launched last year to encourage homeowners to build rain gardens to improve water quality in the Delaware Bay, Delaware’s inland bays and Maryland’s coastal bays. Partners in the project include UD Cooperative Extension, the Delaware Department of Natural Resources and Environmental Control (DNREC), the Center for the Inland Bays, Delaware Nature Society and other agencies.

In addition to doing good, rain gardens look good. “Rain gardens are an attractive way to reduce impact on the environment,” says Budischak. “And you don’t need a huge property to have a rain garden.”

She has seen successful rain gardens as small as 10 feet by 15 feet. On the other end of the spectrum, rain gardens on UD’s Newark campus range from less than 1,000 square feet to more than 3,000. In addition, a large rain garden was installed on the Lewes campus last year, says Tom Taylor, UD’s landscape engineer.

Rain gardens were at UD long before the term “rain garden” was coined, says Taylor. He spearheaded the installation of a rain garden – at the time called a bio-retention basin – at the Dickinson residence complex in the early 1990s.

UD’s rain gardens have always had an environmental function but now the gardens serve an educational role, too. “The key is signage,” notes Taylor. “It’s important to have signs at the rain gardens so that people know what they’re looking at and understand how they can do something similar at home.”

Taylor added plantings to a bio-swale at his Lewes home and used the campus gardens for inspiration. Plants on the exterior of a rain garden must tolerate both dry and wet conditions while plants inside the garden need to handle very wet conditions. (A rain garden’s interior is designed to hold water for up to 48 hours.)

On the edges of a rain garden, Taylor likes native ornamental grasses, asters, goldenrod, blueberry bushes and red-twig dogwood. For the interior, he frequently chooses clethra, cardinal flower, iris, button bush and winterberry. Other options that Budischak suggests are turtlehead, Joe-Pye weed, dwarf fothergilla, sweetbay magnolia and river birch.

Living in Sussex County, Taylor doesn’t have to contend with the single biggest obstacle to a successful rain garden – heavy clay soil. That’s a problem most New Castle County residents must overcome because clay soil inhibits water infiltration.

Taylor recommends replacing a foot and a half of heavy clay soil with a rain garden soil mix to improve drainage.

Other considerations in building a rain garden are size and location. Although it would seem logical to install a rain garden in a low area that doesn’t drain well, this is a poor choice because it won’t support plant growth. The ideal place for a rain garden, says Budischak, is gently sloping ground where stormwater drains off grass or impervious surfaces.

Garden size depends on the size of the area from which you are capturing runoff, soil type and depth of the garden. Many homeowners seek professional advice about the garden’s size and soil requirements before tackling installation and planting. UD Botanic Garden intern Rebecca Pineo created a how-to guide to rain gardens, which can be found online.

For more information about the Rain Gardens for the Bay program, go to the website.

Article by Margo McDonough

Photo by Danielle Quigley

The original posting of this article can be viewed on UDaily.

 

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For the love of limas

May 5, 2011 under CANR News, Cooperative Extension

Pole lima beans are a Delaware staple.

April 20 was National Lima Bean Respect Day but in Ronald Dodd’s eyes, limas deserve kudos every day of the year.

The Georgetown septuagenarian has been growing pole limas since he was a boy and says that his father and grandfather grew them before he did. Dodd’s 55- by 147-foot garden, on land he owns one block off Georgetown’s Circle, features 42 to 45 hills of pole limas each season.

Come harvest time, he’ll enjoy pole limas in succotash accompanied by baking powder biscuits, just like scores of other native Delawareans.

But head a couple hundred miles from the First State, or talk to new state residents, and you may get puzzled looks at the mention of pole limas. “At conferences, I’ve met people in the agricultural industry who have never heard of pole limas,” says Emmalea Ernest, aUniversity of Delaware Cooperative Extension associate who specializes in lima bean research. “But there is a long tradition of growing pole limas here; there is a real lima bean culture in Delaware.

“As a plant breeder, the most interesting thing to me about pole lima beans is that it is still possible to find people in Delaware who are growing local landrace varieties that they have selected themselves or that have been passed down in their families.  For other vegetables, even though there are lots of people out there growing heirloom varieties, they got the seed from Burpee, not their grandmother.”

Lima beans are a big business in Delaware. Limas are grown on more acres in the state than any other vegetable crop. However, the commercial market is made up almost entirely of baby limas and Fordhooks, not pole limas. These baby limas and Fordhooks are grown for processing, which, nowadays, means flash-frozen, not canned.

If you want to eat fresh lima beans this summer, you’ll need to be on the look-out for pole limas at farmers’ markets, particularly markets in Sussex or Kent counties. Or, better yet, you can grow them yourself, suggests Ernest.

She knows, though, that some folks may need convincing that it’s worth the effort to grow limas, pole or otherwise. Maybe they weren’t paying attention on National Lima Bean Respect Day. Or, more likely, they still have vivid memories from childhood of mushy, over-cooked canned limas heaped high on dinner plates or school lunch trays.

There’s nothing worse than a soggy canned lima but these days, flash-frozen baby and Fordhook limas are tasty and have a nice, firm texture, says Ernest.

And there’s absolutely nothing better than a fresh-picked pole lima, she says. “The taste of a pole lima is delicious and the pole lima isn’t starchy, unless you leave it on the vine too long. My four-year-old daughter, Irene, just gobbles them up.”

As an added bonus, pole limas – and limas in general – are nutritional powerhouses. They’re rich in fiber, potassium, iron, copper and manganese.

In her own Ellendale garden, Ernest doesn’t bother growing baby limas or Fordhooks – “I am able to get enough of them at work,” she says. But she has devoted 400 feet of trellis to pole limas.

If you want to grow pole limas this summer, now’s the time to prepare. Pole limas have a long growing season and should be planted between mid-May and early June. Pole limas can be grown on teepees but Ernest prefers trellises because teepees can blow over in windy conditions. Pole limas can tolerate New Castle County’s heavy, clay soils as well as Sussex’s sandy conditions.

Ernest starts her pole lima plants from seed. You can buy seeds online; pole lima plants are available at some independent nurseries and farmers markets. One of the most popular varieties is Dr. Martin, an heirloom that features 16- to 20-foot-long vines bearing large, flat pods. Big Mama and King of the Garden are other local favorites. For something different, try the Christmas Lima, sporting a red and white speckled bean that has a butter-like texture and a subtle chestnut-like flavor.

Pole limas need a lot of room and should be planted four to six feet apart. To keep your pole limas happy, Ernest says to go heavy on the watering and light on the fertilizing. Keep an eye out for spider mites and stink bugs; the two most common lima pests. Pod development should start occurring in mid- to late-August, with mature beans ready to pick about three weeks later. Pods will continue to develop into September.

If you have a bumper crop of pole limas you can freeze them or, like Ronald Dodd, you can give the excess to friends and neighbors. “I have plenty of ‘customers’ who like to get some of my pole limas,” says Dodd. “But last year was not a great season; I didn’t have any extra to give away.”

Plenty of native Delawareans – and Delawareans in the know – will be hoping for better pole lima yields this growing season.

Article by Margo McDonough

Photo by Danielle Quigley

This article can also be viewed on UDaily by clicking here.

 

 

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Stink bugs shouldn’t pose problem until late summer

April 1, 2011 under CANR News, Cooperative Extension

Last fall, Stephanie Sturmfels battled stink bugs at her Pike Creek home and yard. “Stink bugs were on my deck, they were on my front porch, some were even in my house,” recalls the mother of two small children. “My four-year-old daughter, Madison, would go around and collect stink bugs in pieces of tissue.”

Now that spring has arrived, Sturmfels is worried that stink bugs may return in full force. So far, she has seen a few stink bugs but nothing like the invasion last September and October.

Brian Kunkel, a UD Cooperative Extension entomologist, has some good news for Sturmfels and anyone who despises the brown marmorated stink bug. “The adult stink bugs that were driving people crazy last fall will be giving birth this June and dying off soon afterwards. From now until then, they will be too busy feeding on plants in the landscape to spend much time around houses.”

“Their offspring — the nymphs — will spend most of the warm-weather months outside as they mature. They don’t feed in houses so you shouldn’t expect to see many on decks and patios or inside houses this summer,” adds Kunkel.

Best yet, nymph stink bugs can’t fly — they have wingbuds but not mature wings — so they can’t land in your hair, on your shoulders, or in a bowl of potato salad, the way those annoying adults were doing last autumn.

So rest easy and host a Memorial Day or Fourth of July cook-out, says Kunkel. You shouldn’t worry about scads of brown marmorated stink bugs crashing the party. However, when Labor Day rolls around, your guest list could unexpectedly rise.

“By late August, the nymphs have become adults and are able to fly,” says Kunkel. “What’s more, they start to congregate in houses, decks, garages and other warm spots during this time period. There is a lot that researchers don’t yet understand about the stink bug’s behavior but we do know that cooler temperatures at night motivate them to seek shelter.”

Twenty-six states now have populations of the non-native brown marmorated stink bug. If you have friends in other regions who shrug off stink bugs as a minor annoyance, you may have already guessed that Delaware has more of the critters than most places.

“This region is the epicenter of the stinkbug outbreak,” says Kunkel. Brown marmorated stink bug were first found in this country in Allentown, Pa. They arrived in 1998, as stowaways in packing crates from Asia, where they’re native. Here in the U.S., they have few natural predators. Some spiders, including arboreal spiders, feed on the brown marmorated stink bug.

“Don’t get rid of spiders in your yard and garden,” notes Kunkel. “Spiders are beneficial. In addition to stink bugs, they eat a wide variety of other pests.”

Keep in mind, though, that not all of Delaware’s stink bugs are bad guys; a native stink bug known as the spined soldier bug eats aphids and other pests. Delaware is home to three other native stink bugs: green, brown and dusty.

The brown marmorated stink bug has been more of a nuisance than a pest in the home landscape, thus far, but Delaware’s agricultural industry is monitoring the insect closely. This stink bug feeds on many plants, including lima beans and sweet corn, but is a particular threat to fruit-bearing trees.

“There are some orchards in other states that may go bankrupt this year because they had so much fruit damage from the brown marmorated stink bug last year,” says Kunkel.

He and other UD experts are launching several research projects aimed at protecting Delaware’s growers. One project will focus on when the stink bugs arrive in fields or at greenhouses, their life cycle, and the natural enemies (native parasitoids, predators) attacking this pest. Another project will evaluate the effectiveness of insecticides against the brown marmorated stink bug.

According to Kunkel, current insecticides provide little help in keeping this pest out of the house. Exclusion is the best approach. “Seal up every opening — caulk around windows, repair screens, install screens over your attic vents and replace any rotten wood on your house,” says Kunkel.

And take comfort in the fact that you won’t have stink bugs landing in your hair until later in the summer.

Article by Margo McDonough

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Botanic Gardens tour highlights flowering magnolias

March 23, 2011 under CANR News, Events

Magnolias will be featured on the University of Delaware Botanic Gardens tour and at the annual plant sale.

When John Frett leads a guided walk of the University of Delaware Botanic Gardens on March 31, he’s hoping to point out a few early blooming magnolias. More likely, though, he’ll head to the greenhouse to show off magnolias in flower.

Non-native magnolias typically start blooming in Delaware in April while the native varieties wait until May.

With plenty of other March blooms to enjoy — winterhazel, forsythia, hellebores and some dogwoods — why the rush to spot magnolias?

The walk is a spring tradition that highlights plants available at the UD Botanic Gardens Plant Sale. Along with winterhazel, magnolias will be a featured plant of this year’s sale, which is open to the public April 29-30.

Almost everyone loves magnolias. Frett, the director of the UD Botanic Gardens, is no exception. However, he’s reluctant to single out a best-loved cultivar or species. “It’s like picking a favorite child, they’re all fabulous,” says Frett.

Magnolias vary widely. The 80 or so recognized species include trees and shrubs; deciduous plants and evergreens; cold-hardy varieties that do well in Maine and others that flourish in the tropics. About the only thing they have in common are the distinctive, tulip-shaped flowers. And most — but not all — are highly fragrant.

Under Frett’s leadership, the magnolia collection at the UD Botanic Gardens has been expanded to 100 taxa of magnolia, with some 125 magnolias in all.

“The UDBG’s fantastic collection of magnolias includes a nice variety of native and non-native species and cultivars,” says Sue Barton, Cooperative Extension’s ornamental horticulture specialist.

Magnolias are widely scattered throughout the UD gardens but large groupings can be found between Townsend and Worrilow Halls, south of Townsend, and also north of UD’s outdoor pool.

In assembling the collection, Frett looked for a progression of flowering, from the earliest species, in April, to varieties that are still going strong in June. He also included rich and unusual colors, found in the hybrid varieties. In addition to characteristic pink or white petals, magnolia blooms can be light to medium purple, deep purple that is almost red, and yellow.

Barton has one of the yellow varieties in her backyard. “I bought the ‘Elizabeth’ cultivar from the UDBG sale a number of years ago because my older daughter is named Elizabeth,” she explains. “This tree will be covered with yellow flowers in about a month.”

Despite its name, “Elizabeth” isn’t Barton’s favorite backyard magnolia. That distinction goes to the native sweetbay magnolias growing near her patio. “They’re multi-stemmed so they help enclose the patio but you can still view through them so they don’t make it claustrophobic,” she says.

Carrie Murphy, the Extension horticulture agent for New Castle County, says the sweetbay is the top pick for most Delaware gardeners. “Including me,” she adds.

“The sweetbay magnolia is by far one of my favorite plants — it has beautiful late spring and early summer blooms and is lightly fragrant.”

But what Murphy really likes about the sweetbay isn’t apparent at first glance. “I love the underside of the foliage — when the wind blows and rustles the leaves, the silver underside of the leaves becomes visible and it’s absolutely gorgeous,” she says.

Several sweetbays have been added to the Master Garden Demonstration garden at the county Extension office in Newark. At the demo garden, home gardeners often ask for recommendations for small flowering trees and sweetbay nicely fits the bill. It prefers moist soil and some shade and even works well in wet sites. But it’s also adaptable to drier conditions, says Murphy.

Three cultivars of sweetbay will be available at the plant sale: “Mardi Gras,” with a butter-yellow variegated leaf; “Perry Paige,” a new dwarf variety only five to eight feet tall; and “Green Shadow,” a selection that Frett describes as “nearly an evergreen.”

Two other native magnolias will be sold, Magnolia macrophylla “Big Leaf Magnolia,” featuring huge leaves with a tropical feel and Magnolia pyramidata “Pyramid Magnolia,” which is considered rare. Also available will be three hybrids from native species, including two that originated from a cross with the native cucumber tree.

Guided walk

March 31: An hour-and-a-half walk through the UD Botanic Gardens, focusing on plant sale selections. 4 p.m. $5. Call 302-831-2531 or email [kelsch@udel.edu] to register. Maximum 35 people.

UDBG plant sale

Public sale hours are 3-7 p.m., April 29; 9:30 a.m. to 4 p.m., April 30. For more information, call 302-831-2531 or go to the UDBG website.

Article by Margo McDonough
Photos by Danielle Quigley

This article can also be read online on UDaily by clicking here.

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Master Gardeners offer vegetable garden workshops

February 24, 2011 under CANR News, Cooperative Extension, Events

Vegetable gardening continues to surge in popularity. An estimated one in every three American households grows some type of veggies, whether it’s a solitary tomato plant on a deck or a showcase of raised beds with wrought-iron garden stakes, irrigation systems and obelisks for climbing vines.

With all this interest in growing edibles, it was a no-brainer for New Castle County Master Gardeners to choose a program focus this spring. Two thirds of the workshops are dedicated to edibles.

“Our vegetable workshops fill up right away so we decided to offer even more vegetable classes this year,” says Carrie Murphy, horticultural agent for New Castle County Cooperative Extension. “For the second year in a row we’ll have separate classes for novice and experienced gardeners. We’ll also present specialized sessions, such as a workshop devoted exclusively to growing berries and another on starting vegetables from seed.”

Classes get underway in less than two weeks and continue through May. The majority of the sessions are in March, when gardeners are finalizing their plans, and in the case of some crops, starting to plant.

In Delaware, commercial and home growers typically put seed potatoes in the ground on or around St. Patrick’s Day. The Master Gardeners’ potato planting demo, on March 19, details the best methods for success, including mounding techniques and container growing.

The demo appears to fill a need, says Gail Hermenau, a Master Gardener and head of the committee that develops the workshop schedule. “Last year, we offered a tour of our demonstration vegetable garden,” says Hermenau. “When we arrived at the mounded potato beds, a number of people said they didn’t know potatoes grew like that and wanted more information.”

A new tomato class also was created because of popular demand. “A lot of feedback came my way about holding a workshop specifically on tomatoes,” says Hermenau.

Tomatoes top the list of the most commonly homegrown vegetables (even though technically they’re a fruit). Now that more backyard gardeners are growing heirloom varieties, they’re combating new challenges. Heirlooms aren’t disease-resistant, like most hybrids, and they’re more susceptible to cracking and bruising. The March 31 workshop will focus on the pros and cons of heirlooms and other varieties, as well as site selection, seed sources, transplanting, fertilizing and more.

Programming for advanced gardeners includes a workshop on maximizing yields through succession planting, companion planting, crop spacing and other techniques.

Another way to learn about veggie growing is at a Garden Day, held in the Master Gardeners’ Native Teaching Garden on the second and fourth Wednesday, from 9 a.m. to noon, April through September.

On these days, Master Gardeners work in the garden, all the while explaining what they’re doing – from scouting for pests to the right way to weed. They’re happy to answer specific gardening questions, too.

Sussex Master Gardeners also will offer vegetable-oriented programs this spring, including a March 10 session that covers the basics of site location, soil, fertilizing and watering.

“New Gardener in Delaware?,” on May 12, will be useful for vegetable gardeners, as well as those primarily interested in ornamental gardens. This workshop focuses on how to overcome the challenges of growing plants in Sussex’s sand, salt, humidity and heat.

“People move here from Connecticut or the D.C. metro area and think that they can garden the same way they did in their old hometown,” notes Tracy Wootten, Extension horticultural agent for Sussex County. “But Sussex is unique. We teach you how to succeed as a gardener here.”

Check out the spring Master Gardener workshops online. New Castle County classes are at this website and Sussex County classes are at this website.

Register by calling 302-831-COOP in New Castle County. In Sussex, call 302-856-7303.

Article by Margo McDonough
Photo by Danielle Quigley

This article can also be viewed online on UDaily by clicking here.

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Wild animals cope with harsh winter weather

February 10, 2011 under CANR News

Humans may whine about the harsh weather but for most of us winter isn’t a matter of life or death. For many wild animals and birds, the stress of winter is life-threatening. Wild animals and birds must contend not only with extreme weather but with a lack of food and other resources, such as adequate shelter.

Winter adaptations vary by species. Some species migrate, some go into dormancy and some develop a thick skin and tough it out. The thick skin is literal — from the bushy cold-weather undercoat of the fox to the thick winter coat of the raccoon.

Many birds adapt to winter by getting the heck out of here. About half of Delaware’s common summer birds are migratory and depart for warmer climes each autumn, according to Chris Williams, a UD assistant professor of wildlife ecology in the College of Agriculture and Natural Resources.

The birds that do stick around Delaware often form flocks in the winter, comprised of members of the same species, or sometimes flocks of different species (known as mixed flocks). Common mixed flocks include small birds, like chickadees and titmice, which join larger birds, such as nuthatches and woodpeckers.

Flocking is a form of cooperative behavior that rarely occurs during spring and summer nesting season. Williams says that flocking can increase wintertime avian survival rates. Flocks have an easier time securing food since birds are foraging together. And when flocks roost together, heat loss is reduced. Flocking also can provide safety in numbers from predators.

Birds utilize a number of other survival strategies in winter, such as fluffing their plumage, which creates an insulating layer by trapping air. They cope with the cold by shivering, just like we do. And many species increase their metabolic rate to produce more body heat. The downside of this adaptation is that they need to eat more food, even though food supplies are limited.

A handful of species lower their metabolism, but only in the evening when food isn’t available. These birds enter a state called torpor, which causes lowered body temperature and decreased oxygen consumption.

Plenty of mammals also slow their metabolic rate in winter. Groundhogs that live in northerly climes are “true hibernators,” meaning they exist in a state of uninterrupted, deep sleep for six to seven months, with body temperatures so low their metabolisms are almost at a standstill.

However, Delaware’s groundhogs are “semi-hibernators,” says Derek Stoner, conservation coordinator at the Delaware Nature Society.

“In February and March, if it warms up to about 50 degrees, Delaware groundhogs will come out of their burrows,” says Stoner. “By St. Patrick’s Day, the males, in particular are very active on warm days. They visit other burrows in hopes of finding a mate.”

In the fall, Delaware’s groundhogs gained some 50 percent of their body weight to prepare for their long — if somewhat fitful — snooze. But they also stashed grass in their burrows for the occasional snack when they do awake. Chipmunks also are “semi-hibernators” at Delaware’s latitude.

Deer don’t hibernate in winter although they do move around less to conserve energy. In cold conditions, they gravitate to areas with good thermal cover, such as a patch of evergreen trees that’s protected from the wind and cold and thus a degree or two warmer than surrounding terrain.

In the Poconos and Adirondacks you can see herds of several hundred deer hanging out together in the woods. Here in Delaware, herds are smaller, usually about 40 deer. Stoner says that a herd has congregated on Coverdale Farm, near Way Road, for the past several weeks.

Like flocking behavior in birds, herding is a wintertime phenomenon that increases survival rates. Come spring, the herd breaks up and the deer will go their separate ways.

Unlike us, wild animals and birds don’t need to turn to the Weather Channel to know when a storm is brewing; they sense the shift in barometric pressure, says Stoner. While we make our pre-storm trip for milk, bread and eggs, they, too, make a mad dash for adequate provisions before the snow flies.

Article by Margo McDonough

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How insects survive the long, cold winter

February 3, 2011 under CANR News

Baby, it’s cold outside. Time to put another log on the fire, wrap up in a thick sweater, or make a steaming mug of tea. These human adaptations to cold weather are quick, easy and get the job done. Even more effective, of course, is the central heating that is ubiquitous in our homes, offices and schools.

It takes a lot more effort for other mammals, birds and insects to make the necessary adaptations to survive harsh weather. Next week, we’ll look at animal and bird strategies; today we’ll see how insects make it through the winter.

In many species, insects adapt to the cold by dying off; it’s the larval stage of the species that goes through winter. Insects that do over-winter as adults usually enter a hibernation-like state called diapause.

“Insects don’t technically hibernate in winter but many go into diapause, a dormant state that allows them to withstand cold temperatures,” says Brian Kunkel, a UD Cooperative Extension entomologist.

The mourning cloak butterfly exists in a type of diapause called freeze susceptible. It avoids freezing in much the way that car owners do — by adding anti-freeze. This butterfly replaces the water in its body with antifreeze compounds — called cryoprotectants — which supercool its bodily fluids and tissues.

The other form of diapause, called freeze tolerant, is used infrequently by North American insects but is a common strategy of Southern Hemisphere insects. In this type of diapause, the insect freezes its bodily fluids.

Not all insects go into diapause in winter. A few, like the stonefly and mayfly, can be seen out and about in their adult form. The best time to look for stoneflies is after a snowfall — these small dark critters are much easier to spot in the snow.

The social insects take a middle-of-the-road approach to winter. They don’t enter diapause, like many butterflies, but they’re not bounding about, full of pep, like stoneflies. Social insects that live through winter in Delaware include honeybees, termites and a number of different ants.

Many of the social insects, including ants, consolidate their living quarters during the winter, says Deborah Delaney, an assistant professor in the Department of Entomology and Wildlife Ecology in UD’s College of Agriculture and Natural Resources. In late fall they move deeper into their nests and close up the exit with soil, leaves and other organic materials.

Honeybees slow down in winter and stick close to the hive. The focus is on eating and huddling close to each other on cold days, notes Delaney.

When the hive temperature drops below 64 degrees, honeybees cluster together into a carefully organized, compact ball. The interior bees generate warmth by vibrating their wing muscles. The outer bees are motionless, acting as an insulation layer. The colder the temperature outside, the tighter the cluster. A single bee can increase heat production 25-fold.

The honeybees take turns enjoying the warmth in the middle of the huddle and then move to the outside. Not surprisingly, the queen bee reigns supreme in the middle and never takes a turn on the outskirts of the huddle.

Despite huddling and other strategies, winter takes a toll on honeybees, says Delaney. Hives that may have had a peak of 60,000 bees in the summer may diminish to 20,000 bees by mid-winter. Some hives are totally lost, due to insufficient food or other factors.

Worker honeybees toiled long hours in the fall, collecting nectar to feed and maintain the colony until spring. If their work wasn’t adequate, there is nothing they — or Delaney — can do about it now, in the depths of winter.

Nonetheless, Delaney checks on the hives at UD’s Apiary about two to three times a week this time of year. “I hold my ear to each hive and if I hear buzzing inside, I know everything is good,” she says.

“The hives are kind of like my fourth child,” admits Delaney, who is the mother of three small children.

Article by Margo McDonough

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Extension agent encourages winter exploration

January 13, 2011 under CANR News, Cooperative Extension

This is the season when many nature-lovers page through seed catalogs, polish their binoculars and dream of warmer and brighter days. But then there are the hardy types, like Dot Abbott, who consider winter the perfect time to get outside.

“During the cold-weather months, I appreciate aspects of nature that I take for granted at other times of the year,” says Abbott, a renewable resources agent for University of Delaware Cooperative Extension. “With the foliage gone, it’s a lot easier to see animal habitats and to notice wildlife. For example, a male Northern cardinal will really stand out amid the browns and grays of the forest in January.”

Abbott is responsible for Extension’s forest conservation education program, which teaches Delawareans about forest ecosystems. Much of the programming takes place at the outdoor woodland classroom located at UD’s Carvel Research and Education Center in Georgetown. Abbott also utilizes woodland classrooms at Delaware State University and Blackbird State Forest.

Abbott works with both adult and youth groups but especially enjoys training childcare providers because they help very young children become attuned to nature.

“Exposure to the natural world is an essential part of growing up,” says Abbott. “It increases a child’s awareness and improves observational skills.”

“In the winter, I do an activity with childcare providers and other visitors that encourage them to fully utilize their senses,” adds Abbott. “Without the visual distractions of green leaves and bright flowers, they may find it easier to tune into auditory stimuli — the crunch of dry, withered leaves under foot, the whistle of the wind, the calls of noisy blue jays or the high-pitched, whistling call of the Eastern screech owl.”

She encourages visitors to fine-tune their sense of smell, too. Though most of us don’t think of winter as being a particularly fragrant time of year, Abbott says to think again. Decaying leaves give off an earthy, musky scent; fox dens offer pungent smells and pine trees have a crisp, clean scent that’s synonymous with the holidays.

Abbott uses those pine trees, as well as other trees, to illustrate different textures found in nature. Some bark is smooth, such as on the American beech; some is ridged, like on a tulip poplar; some is peeling or flaky, like that of the yellow birch or sycamore.

As for pine, the texture depends on the species. While most pines have thick and scaly barks, a few species have thin, flaking barks.

To Jimmy Buffett, a change in latitude brings about a change in attitude. For Abbott, as she leads her woodland classrooms tours, it’s all about a change in altitude.

She’s not talking anything drastic, though, just the change in altitude found when one squats or kneels rather than stands erect. “Get down low and you’ll notice all sorts of things on the forest floor,” says Abbott. “If you’re near a riverbank you may see small black insects — these are stoneflies, one of the few insects that are active during a Delaware winter. You may see chipmunks, a cache of nuts under a tree, animal tracks or scat. If you had remained standing, you may not have noticed any of these things.”

And if you hadn’t braved the cold and ventured out, you definitely wouldn’t have seen any of these things.

Abbott offers free, one-hour guided tours of the outdoor woodland classroom to groups, individuals and families. She also offers a forest ecosystem lesson to groups who are not able to travel to the outdoor classroom. For reservations and more information, call Abbott at 302-730-4000 or email her at [dotad@udel.edu].

Article by Margo McDonough

This article with accompanying photos, can be viewed online on UDaily by clicking here.

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