Spring means lush blooms and wide variety of beneficial bugs

March 20, 2013 under CANR News, Cooperative Extension

assassin bugSpring officially gets underway March 20, bringing blooms, birds and bugs. Lots of people get excited about the first redbud flower or returning tree swallow. Fewer get enthused about the first Eastern tent caterpillar or green lacewing that emerges in spring.

But a wide variety of flowering plants and songbirds wouldn’t exist without insects. “A number of different insects pollinate plants and many are an important protein source for birds,” notes Brian Kunkel, an entomologist with University of Delaware Cooperative Extension.

Bugs get a bad rap, says Kunkel. Some bugs – stink bugs, Japanese beetles and yes, Eastern tent caterpillars — deserve the nasty reputation because they damage or destroy ornamental plants, turf grass or agricultural crops.

But many insect species are innocuous – they do no harm. And plenty more, like immature green lacewings, are good guys.

While the adult form of this insect eats pollen and nectar, the young green lacewing gobbles up a slew of pests, including white flies, aphids, adult mealy bugs, and mealy bug eggs and larvae.

“Beneficial insects far outnumber the pests,” says Kunkel. “In fact, more than 97 percent of arthropods typically seen in the home landscape are either beneficial or innocuous.”

(Arthropods, as you may recall from your school days, include not only insects but also spiders, predatory mites and other creepy crawlies.)

Gardeners often grab a can of pesticide at the first sight of a bug, without even bothering to figure out whether the species is a pest.  Retired Hercules technologist and current Master Gardener Frank Ebright used to do that, too.

“I spent my career working with chemicals. I have nothing against them; chemicals have helped to save lives. But I don’t see a need for them in my garden,” says Ebright.

He tends to a two-acre yard in Cecil County, Md. Once he became a Master Gardener 19 years ago, Ebright’s use of chemical pesticides declined but he still spot-treated roses and other plants with pest problems. About five years ago he abandoned lawn chemicals for good and reports that his landscape has never looked better.

“Once I got rid of the chemicals, the beneficial insects starting coming to my yard and taking care of my pest problems,” he says.

Ebright will be leading a Master Gardener workshop about beneficial insects and integrated pest management on May 16. “I want gardeners to use chemical control as a last resort, not the first defense, and learn who their friends are.”

Sometimes it’s easy to identify your friends. Even though there are some 150 species of lady beetles in the U.S., these beneficials are a cinch to recognize. Their size and color may vary but all sport characteristic spots on their abdomens.

Other times, it’s tough to tell friend from foe. For example, the hover fly looks like a stinging hornet but the adult form is a first-rate pollinator that has been ranked just after the honeybee in its effectiveness. Plus, the larvae of many species of hover flies gorge on aphids, a pest that can wreak havoc on everything from roses to maple trees.

Ebright’s go-to book for identifying insects is Garden Insects of North America by Whitney Cranshaw. If he sees an unknown bug, he snaps a photo of it then compares it to images in Cranshaw’s book.

One of the first steps in integrated pest management is “making sure your plants are happy,” says Kunkel. Essentially, that comes down to “planting the right plant in the right place,” he notes.

If a plant requires moist soil, don’t put it in a dry spot. If it needs full sun, don’t think you can get away with partial shade. A stressed plant won’t be happy and can be more vulnerable to pest infestations, says Kunkel.

Companion plants are another element of integrated pest management. Nasturtium is commonly used as a companion plant, especially in vegetable gardens. Plant nasturtium near cabbage, tomatoes, cucumbers, broccoli, collards and kale. The aroma of this colorful annual will repel aphids, squash bugs and striped pumpkin beetles.

Presentations

• May 16, 6-8 p.m.: Find out how to use integrated pest management for an attractive yard and productive vegetable garden. New Castle County Cooperative Extension Office, Newark. $25. To request a registration form, call 302-831-COOP or download the form online.

• June 11, 6-8 p.m.: Join Brian Kunkel and other experts for a plant, pest and beneficial insect walk. New Castle County Cooperative Extension Office, Newark. Free. Register by email to cjmurphy@udel.edu.

Article by Margo McDonough

Photo courtesy of Brian Kunkel

This article can also be viewed on UDaily.

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Native Delaware: January is planning time for area vegetable gardeners

January 9, 2013 under CANR News

Native Delaware BeatsThe wind howls at the windowpanes. The sun makes a brief appearance but departs before the workday is over.  In the woods, the white-tailed deer huddle together for warmth.

In January, it’s easy to believe that spring will never arrive. But some folks, like Master Gardener Rick Judd, disregard the signs of winter around them and already are gearing up for spring.

“I’m making my seed selections now,” says Judd, who gardens on a small but prolific plot at his suburban Newark home. “You’d be surprised how early you can plant. By mid-March, I’ll be direct seeding onions, scallions, radishes, spinach, beets, peas, kohlrabi, several types of lettuce and more.”

Judd will be out in the garden even earlier – usually by the first of March – pulling weeds, raking the soil, and amending with fertilizer so he’s ready for planting day.

An avid gardener for more than 20 years, Judd knows that vegetables are divided into two major groups – cool-season and warm-season crops. Cool-season veggies can handle chilly conditions and even frost. In fact, the biggest threat to cool-season crops is warmth. Gardeners must plant these veggies early enough that they reach maturity before temperatures heat up too much. In contrast, warm-season crops, like tomatoes, corn and watermelon, can’t be planted until after the last frost. Since the warm-weather growing season is fairly short in Delaware, these veggies are usually transplanted into the garden rather than directly seeded.

Judd realizes that many new gardeners are clueless about these distinctions. They mistakenly think that nothing can be planted until after the risk of frost has passed. More experienced gardeners may understand the difference between cool- and warm-season crops but are tomato or sweet corn snobs. They couldn’t be bothered getting out in the garden early to grow watercress, chive, endive and other “little, green things.”

Judd hopes to get more gardeners juiced about cool-season crops at a “Grow Your Own Spring Salad” Master Gardener workshop on Jan. 29. He’ll reveal his secrets to success, from choosing the right cultivars for local growing conditions to scouting for pests.

He’ll also share the surprisingly long list of cool-season vegetables that can be grown. In addition to his staple crops of lettuces, radish, spinach, beets, scallions and onion, Judd says he often plants “several more exotic choices, like arugula or kohlrabi.”

Other cool-season vegetables that can be grown in Delaware include beet, bok choi, broccoli, Brussels sprout, cabbage, cardoon, carrot, cauliflower, celery, chard, chicory, fava bean, fennel, kale, pak choi, kai-lan, parsley, peas, Swiss chard, turnip and watercress. Plus, there are a number of perennial cool-season selections, including asparagus, rhubarb and horseradish.

Overwhelmed? No need to be. First, while it may sound obvious, grow the stuff you like, says Judd. If you don’t like chard from the supermarket you probably won’t like it even when it’s grown in your own backyard.

Secondly, “plant stuff that’s reasonably easy to grow,” says Judd. Leafy greens are probably the easiest cool-season veggies to grow. This includes all types of lettuce, especially leaf lettuces.

The good news is that, in general, cool-season vegetables are some of the easiest plants to grow.  “This isn’t like growing orchids,” notes Judd. “God was good to us in that he made a lot of our foods fairly easy to grow.”

Learn More

“Grow Your Own Spring Salad” will be held Jan. 29, 7- 9 p.m., at the New Castle County Cooperative Extension office in Newark.  The workshop costs $20. To register, call 831-COOP.

Want to be a Master Gardener?

If you’d like to share your gardening knowledge with others, like Rick Judd does, train to be a Master Gardener. The 2013 training program in New Castle County will be held from March to May on Tuesdays and Thursdays from 9:30 a.m. to 12:30 p.m. Applications are available at: http://extension.udel.edu/lawngarden/master-gardener-volunteer-educators/become-a-master-gardener/  or contact Carrie Murphy at 831-2506.

Article by Margo McDonough

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UD Cooperative Extension entomologist says summer insect populations uncertain

April 9, 2012 under Cooperative Extension

Recently, we’ve heard water cooler and dinner table pronouncements that it’s going to be a bad summer for mosquitoes, stink bugs and other insect pests. Prognosticators cite the mild winter and the fact that insects are out earlier this spring as their rationale.

Not so fast, says Brian Kunkel, University of Delaware Cooperative Extension entomologist. “The mild winter may not make much difference in the size of the insect populations this summer.  In terms of the early spring, yes, most insects are emerging or arriving about two weeks ahead of schedule,” he says. “But it’s too soon to say what impact — if any — this will have on insect populations later this season. There are many variables that could impact different species, either adversely or favorably.”

“Keep in mind, when I refer to insect populations I’m not just talking about pests,” he adds. “Beneficial insect populations — such as lady beetles — also are vulnerable to these variables.”

On the adverse side of things, some insects have become active sooner than their plant food source has become available. Various factors, not just air temperature, influence when plants bud. Photoperiod — the relative length of light and dark each day — is an important trigger for many plant species.

“We could see insect populations crash if their food source hasn’t bloomed or leafed out and they can’t obtain enough food,” says Kunkel.

Plant-eating insects that are host-specific — meaning they eat only one type of plant or from one plant family — are more vulnerable to such a crash.

Weather conditions during the rest of the season can be just as critical to many insect species as what already happened in winter and early spring.

“If the spring turns cool and damp, it could mean fewer insects in summer,” notes Kunkel. That’s because cooler, damper weather brings greater number of fungi that attack insects. A hot, dry summer could be even worse. Hot, dry conditions can make it difficult for some insects to survive.

Although Delawareans are tackling pesky insects earlier than usual, there is an upside. At the end of the season you’ll say goodbye to these pests that much sooner.

“The insects are going through their normal life spans, just earlier,” points out Kunkel. “For example, you may see Japanese beetles eating your roses earlier than normal this June. But, if that happens, then the beetles may peter out in August, instead of September.”

It’s anybody’s guess as to how bad insect pests will be this summer. But these tips, from Kunkel and the National Pest Management Association, are good advice in any season:

  • Trim back tree branches and other plants near the house.
  • Keep mulch at least 15 inches from your house’s foundation.
  • Get rid of standing water and other sources of moisture.
  • Make sure you don’t have holes in your screen windows and doors.
  • Seal cracks and small openings along the bottom of the house.
  • Tightly seal outdoor trash cans.
  • Learn about good bugs

Beneficial insects play an important role in the garden. Learn how beneficial insects can help manage your pest problems at this Master Gardener workshop to be held from 6-8 p.m., Wednesday, May 2, at the New Castle County Extension office in Newark. Cost is $15. Call 831-COOP to register and for more information.

Article by Margo McDonough

Photo by Danielle Quigley

This article can also be viewed on UDaily

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Fall in bloom

September 8, 2011 under CANR News, Cooperative Extension

“I love fall plants, fall temperatures, fall colors, fall sounds. I think it’s the best time of the year for gardening,” enthuses Suzanne Baron, a Master Gardener with University of Delaware Cooperative Extension.

The “third season” is ramping up for Delaware gardeners and many, like Baron, consider it the very best season. It’s starting to get cooler, especially early and late in the day, making it easier to accomplish garden chores. It also happens to be an excellent time of year to get plants in the ground, notes Sue Barton, ornamental horticulture specialist with UD Cooperative Extension.

“Fall’s cooler temperatures and typically higher rainfalls help plant roots become well-established. The soil is still warm and allows roots to grow until the ground freezes,” says Barton. “In contrast, plants may get off to a slower start in spring because the soil is cooler and in summer new plantings can become stressed from heat and drought.”

Planting for fall interest is easy because there’s a wide range of perennials and shrubs that exhibit good color, in addition to the dramatic foliage of many deciduous trees.

At the Teaching Garden at the county Extension office in Newark, Baron and her fellow Master Gardeners have planted thread-leaf irownweed, which already displays bright purple flower tufts that will continue through early fall.  Another purple bloomer, Joe Pye weed, also is in flower. And while the pale blue flowers of Bluestar are long gone, its leaves will soon turn bright yellow. Later in the season, the black gum trees will turn bright red and the aromatic sumac shrubs will display brilliant orange, red and yellow leaves. Plus, the Teaching Garden features one of Baron’s fall favorites, goldenrod.

Baron has planted many varieties of goldenrod — ranging in color from vivid yellow to deep gold — at her farmette outside of Middletown. “I keep adding different ones to fill different needs in my gardens,” says Baron. “The flower lasts a long time and even in late October bees visit it.”

“Goldenrod is a great source for nectar in the fall,” notes J.W. Wistermayer, a Master Gardener who strives for a “riot of color” in his Newark-area yard.

Goldenrod and other fall blooms don’t just add pizzazz to the landscape, they also help out bees and other insects.  “Fall is an incredibly important time to think about flowering plants in the garden so that insects have a supply of nectar and can make it through the winter,” says Wistermayer.  “A lot of people think about planting for the pollinators in the spring and summer but tend to forget about it in the fall.”

In addition to goldenrod, pollinator-friendly choices include asters, spicebush and Joe Pye weed. “Joe Pye Weed is awesome as a nectar source and the hollow stems can be used by native bees when they lay their eggs,” says Wistermayer.

Carrie Murphy, horticulture agent for New Castle County Cooperative Extension, says that her home garden in North Wilmington starts out strong in spring but can be iffy in summer. She says the garden invariably “comes back to life” in the fall.

Murphy designed her garden with fall interest in mind, including such colorful choices as Virginia sweetspire, viburnum, blueberry and oakleaf hydrangea. “The oakleaf hydrangea never disappoints with its exfoliating bark, beautiful blooms that dry and hang on through winter and great fall color — reds, yellows, oranges,” says Murphy.

Asters, goldenrod and thoroughwort are the primary fall bloomers on Barton’s 11-acre property in Landenberg, Pa. They are complemented by the foliage of sourgum (brilliant red), sassafras (bright oranges and yellows), sourwood (red), sugar maple (yellowish orange) and red maple (bright red) trees.  She also has planted lots of sweet gums, which turn purple and orange all on the same plant. Most of these trees are at their peak color in October.

Barton also takes a long-range view on fall gardening. “Everyone focuses on fall color — foliage or flower — but bark, branch structure and remaining flower heads can provide a lot of interest,” she says, “especially late in the fall when most of the leaves are gone.”

Article by Margo McDonough

Photo by Danielle Quigley


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