HortusScope, a checklist of garden and nature related things to do in Central Indiana has been posted. This calendar is compiled by Wendy Ford of Landscape Fancies as a pubic service.

The September checklist for the garden has been posted.

A garden spider spins a silky tomb for a bumble bee. © Jo Ellen Meyers Sharp

This time of year, garden spiders spin their orbs in the landscape.

The yellow and black females are larger than the males, more colorful and usually more visible, especially this time of year. The females make the large webs, some up to two feet across, and the males spin smaller orbs around the fringes, each with a zigzag in the center.

The garden spider (Argiope aurantia) is native throughout the United States and is considered a beneficial.

The female garden spider is about one inch long, but is not harmful to humans. She hangs upside down on her web, spun between two plants in a sunny spot protected from wind. The male is narrower and may be brownish. It is about one-fourth to one-third inch long.

When bees, flies, butterflies and other insects become ensnared in the web, the spider shoots them full of venom and quickly wraps them into silky tombs. Some are stored for dinner later, but many are eaten as soon as they are encapsulated. Each day, the female garden spider eats the entire center section of the web and spins a new one. Speculation is she cleans out her pantry of bugs to make way for the new catch of the day.

Late summer is the annual mating and egg-laying season. So risky is his journey into her web that he frequently has a silken tether at his belly that allows him to drop to the ground if she says no. The males die after mating and sometimes make a meal for the female.

She lays her eggs and wraps them into round bundles of silk, with the last layer a brownish color for better camouflage. She hangs the egg sacs on the web where she can guard them against predators. She usually dies by the first frost.

Eventually, the eggs hatch, but stay in their cocoon until spring when they emerge and go their way.

The Fairfax County (Va.) Public School’s Web site has more lifecycle details and other interesting tidbits about this spider.

From Scott Kunst, Old House Gardens Friends of Old Bulbs Gazette

Rain lilies, which open pink then fade as they age, like to be crowded in the pot. © Jo Ellen Meyers Sharp

High heat has plagued much of the country this summer. Some bulbs like it, but others suffer. Dahlias, for example, have struggled or failed in many gardens where they usually thrive. That’s because they come originally from the mountain plateaus of Mexico where days are hot but nights are dramatically cooler. When nights are too warm, dahlias just can’t grow well. Some varieties are more sensitive than others and can even die. The good news is that if you can keep them going till temperatures cool (which has to happen sometime, right?), they’ll kick back into gear and bloom gloriously till frost.

Glads may develop kinked stems in unusually hot weather as they sag a bit during the day, unable to fully replenish the water evaporating from them, and then grow upright at night when evaporation slows. This is most often a problem with glads like ‘Atom’ that have thin, wiry stems. To help, keep your glads well-watered and protect their shallow, wide-spreading roots from disturbance. Tiny sucking insects called thrips proliferate when it’s hot, too, and can leave glad leaves and blossoms mottled, or even prevent buds from opening. Here are tips on control of thrips.

Heat affects flower color, too. Deep-colored lilies such as ‘African Queen’ may be paler in high heat, bicolor dahlias such as ’Deuil du Roi Albert’ may bloom temporarily as solids, and the rosy tones of ’Kaiser Wilhelm’ and others won’t develop fully until the weather cools.

Of course some bulbs love the heat. In many gardens this summer, cannas, tuberoses and rain lilies have been especially happy — and we hope you’ve been enjoying them.

Many lawns have crabgrass this year because of the rain, hot weather and other factors. (C) Jo Ellen Meyers Sharp

Crabgrass is sprouting all over the lawn. And, it’s probably worse this year than in years past, even though you applied a pre-emergent herbicide this spring to keep the weed from sprouting.

There are several factors that caused this bumper crop, not the least of which is the weather. It did nothing but rain in central Indiana during crabgrass’ key germination period in late April and early May. After that, the temps turned hot and stayed there, nourishing tiny seedlings into full-grown weeds.

The weather also contributed to several grass fungus diseases, such as pythium blight and red thread. Like most weeds, crabgrass (Digitaria) is opportunistic and will take advantage of thin, weakened spots in the lawn.

Timing of herbicide applications is also a contributor. Many consumers apply lawn fertilizers with pre-emergent herbicides in March, which is too early. Most pre-emergent herbicides are effective in keeping crabgrass seeds from germinating for about eight weeks. Waiting until April and May to apply the pre-emergent extends protection well into summer.

It’s too late to apply a post-emergent herbicide on crabgrass now, because the weeds are so large and the weed killer is much less effective. Hand pull or hoe out crabgrass from garden beds.

Fortunately, crabgrass is an annual weed, which will be killed by cold temperatures. Draw a sketch of the landscape and indicate which areas were infested so you’ll know where to apply the pre-emergent herbicides next spring.

Other tips:

• Mow grass to 3 ½ high.
• Apply two-thirds of the annual lawn fertilizer in fall, preferably in September and November.
• Irrigate the lawn during extremely hot periods with no rain to keep the grass from going dormant. A dormant lawn is an invitation for weeds to move in.

The Hoosier Gardener talks about crabgrass and offers tips for controlling it Aug. 25 on Indianapolis’ Fox59 Morning News.

For more information, download Purdue University’s Control of Crabgrass in Home Lawns.

The Marion County Extension's City Gardener program covers plants' roots and other details to help you succeed in all of your gardening efforts. (C) Jo Ellen Meyers Sharp

If you are a new or inexperienced gardener or a first-time homebuyer and have questions about what to do when in the landscape, the City Gardener program offered by the Marion County Extension Office, will provide the answers.

Topics in the 12-hour program include: how a plant grows; soil and fertilizers; pests and pest management; tree and shrub selection and care; weed identification and control; lawn care; vegeteable gardening; animal damage management; annuals and perennial flowers.

Participants receive a reference notebook, which contains outlines of the presentation and supporting publications. The two Saturday sessions, Aug. 28 and Sept. 11, 2010, will be at Keep Indianapolis Beautiful, Inc.’s headquarters, 1029 Fletcher Ave., near Fountain Square. There’s plenty of free parking.

The fee is $20. A  $10 scholarships may be available to those with financial need, said Steve Mayer, an extension educator who teaches the program.

Here’s the registration form.

Sunshine Daydream sunflower. (C) Jo Ellen Meyers Sharp

I’m tired and hot from another 90+ degree-day in the garden center. Oh, wait. I wrote that last month!

No change in the weather, only intensified heat. Three days of excessive heat warnings in a row…the hottest here in 22 years.

Despite the constant incredible heat and humidity, there are bright spots in the garden. First up is the charming Sunshine Daydream sunflower (Helianthus multiflorus) from Plants Nouveau, which has reached 5 feet tall its first summer.

Also tall is the volunteer flowering tobacco (Nicotiana sylvestris), which is intensely fragrant. I really like most flowering tobacco because of their fragrance, because they self-sow and because they are a terrific attractant for hummingbirds, butterflies and bees.

Sunshine Charm tradescantia. (C) Jo Ellen Meyers Sharp

A sweet surprise is a brand new spiderwort called ‘Sunshine Charm’ (Tradescantia), which I picked up last month as a plug from the Terra Nova Nurseries booth at OFA, the country’s largest horticulture show held annually in Columbus, Ohio. It and about a dozen other plugs of various sorts have been in 4-inch pots since the show, yet this one is blooming and living up to its name.

Garden Writers Association members from Region III (Indiana, Michigan and Ohio) have been invited the last several years to attend this event at no charge. For the second year, I went for the day with Irvin Etienne, a horticulturist and blogger at the Indianapolis Museum of Art, another GWA member and total plant geek.

I’ve been pleasantly surprised with Ready to Wear Paris, a tri-colored Calibrachoa sent to me from Hort Couture. I’m not particularly crazy about ‘million bells,’ in general, because I don’t think they take the heat very well and they get really scraggly.

Ready to Wear Paris calibrachoa from Hort Couture. (C) Jo Ellen Meyers Sharp

But this new introduction for 2011 has done very well with my usual benign neglect as a companion with another favorite annual, jewels of Opar (Talilnum). I can’t really give more information about this calibrachoa because I can’t find anything about this plant on the Hort Couture Web site, so I don’t know if there’s a Ready to Wear Rome…New York…or?

Lady Elsie May rose pairs nicely with a pink Japanese anemone. (C) Jo Ellen Meyers Sharp

The shrub roses (Rosa rugosa) are blooming again after a brief rest, and I continue to be amazed by ‘Lady Elsie May,’ which is just a lovely plant and stunning color. It’s close to Japanese anemone (A. x hybrida), which also has started to bloom. This pink perennial also is a favorite in winter for its cotton-ball seed heads.

Japanese painted fern has gone dormant because of the heat in central Indiana. (C) Jo Ellen Meyers Sharp

Lastly, my poor Japanese painted ferns (Athyrium niponicum) have melted in the heat. I’ve not watered anything except the pots and the stuff in containers. I’ve only watered the vegetable garden once and that was two days ago.

This coming week is expected to be cooler…in the 80s. It’s hard to imagine the 80s as cooler. A little rain would be nice.

Garden Bloggers’ Bloom Day was started by May Dreams Gardens. Garden bloggers from throughout the world write about what’s happening in their gardens on the 15th of the month.

Jim Wilson was the national spokesman for Plant a Row for the Hungry. (C) Kendra Martin

Jim Wilson, one of my favorite gardeners, educators and communicators died in his sleep at age 85 on Aug. 1 at his home in Columbia, Mo.

One of the early hosts of PBS’ The Victory Garden, Jim was one of the first celebrity gardeners I interviewed for this column in the early 1990s.

A southern gentleman who always wore a wide-brim hat, Jim greeted everyone with “Hello, friend,” and quickly turned the conversation to how our gardens were growing.

He was the author of about two dozen books, including Homegrown Vegetables, Fruits and Herbs: A Bountiful, Healthful Garden for Lean Times, published earlier this year and reviewed here.

In many ways, his speeches, activities and books reflected his own stages in life. In his 50s and 60s, he was a pioneer on public television, encouraging his baby-boomer audience to dig in the soil and plant a garden. He was the national spokesman for Plant a Row for the Hungry, a program of the Garden Writers Association. A longtime member of GWA, Jim was named a Fellow in 1988 and elected to the Garden Writers Hall of Fame in 1995.

In an interview upon publication of Gardening Through Your Golden Years in 2003, Jim said “as we age, we are reluctant to admit we are getting older and slowing down. I’ve slowed down myself, a little. I started analyzing what was happening to me physically and what happened to gardening and how your perspective changes year to year.”

His longtime companion, Janie Mandel said that just about every day, he worked in the vegetable garden she designed for his 80^th birthday, planting, weeding, harvesting and frequently cooking the food he grew.

“There’s a common thread of optimism among gardeners,” Jim said in our 2003 interview. “There’s always the hope that next year’s garden will be better than last year’s garden.”

Thank you, Jim. Rest in peace.

Indiana firefly on U-Haul truck. Photo courtesy U-Haul.

From Tom Turpin, Purdue University

West Lafayette, Ind. — In size, it’s certainly not your average firefly. But like real fireflies, its 5-foot-tall image on the side of U-Haul trucks is an attention-getter.

The first trucks sporting the giant firefly, which represents Indiana, began rolling along North American roads in late July.

The firefly is the 135^th design in a 20-year series, known as SuperGraphics, to appear on U-Haul vehicles. This program, called Venture Across America, features facts and mysteries associated with U.S. states or Canadian provinces.

The firefly is the third insect depicted in this new series. The others are a Gulf fritillary for the state of Louisiana and a dragonfly for the Canadian province of British Columbia.

It’s appropriate for the Indiana graphic to feature the firefly. After all, nothing says Indiana better than the images of fireflies flickering across meadows, woodlands and crops on warm summer nights.

Big dipper firefly. Photo courtesy Purdue University

The big-dipper firefly (Photinus pyralis) is featured on the graphic. It is the most common of the more than 40 species of fireflies found in Indiana. The shape of the light pattern produced by its flashing looks like the big dipper star constellation.

Big dipper fireflies hover between 2 to 3 feet above the ground, both before and after producing a light flash. Such behavior makes the insect easy prey for firefly seekers.

This species also begins flashing at dusk. Consequently, most children who engage in the great firefly chase fill their bug jars with the so-called big dippers.

The Indiana firefly graphic not only shows the insect in flight but the nostalgic scene of children capturing fireflies in a canning jar. Also in the graphic is part of a chemistry equation explaining how the light is produced. Steve King is the illustrator for the graphic. He is located in Phoenix and has produced 60 graphics for the U-Haul SuperGraphics program.

The firefly illustration is based on the photographic work of Evansville, Ind.,-based photographer Terry Priest, who has mastered the technique of photographing fireflies in flight as they produce light. Some of his wonderful shots of the big dipper firefly can be found on his Web site.

The graphic introduces the concept of bioluminescence, the scientific term for light production by living organisms. It also has part of a chemistry equation explaining how the light is produced.

Purdue entomologist Tom Turpin models t-shirt fashioned after firefly image on U-Haul truck. Photo courtesy U-Haul.

A firefly is a very visible aspect of Indiana’s natural environment, history and culture. For example, Thomas Say, the so-called father of entomology in North America, lived in New Harmony, Ind., where he described and named numerous insects native to America, including a firefly that was probably collected in Indiana.

Although lightning bug and firefly are common names for this insect, it is neither. It’s a beetle.

There have been several unsuccessful moves to have the firefly declared Indiana’s state insect.

(C) Photo Jo Ellen Meyers Sharp

One of the easiest and fastest ways to get new plants is from herbaceous cuttings. The Hoosier Gardener demonstrates how to make these cuttings and pot them up Aug. 11, 2010 on the Morning News at Indianapolis’ Fox 59.

Begonias, impatiens, geraniums and coleusare just a few of the annuals growing in the garden now that can be propagated this way. These plants can be grown indoors in a bright sunny window for enjoyment long past the summer season. Houseplants and perennials also can be propagated through herbaceous cuttings.

Here’s how to take herbaceous cuttings:

• Water the plants well the day before.
• Clean your snips, scissors, knife or other tools with a solution that is 1 part bleach and nine parts water. This is called a 10-percent bleach solution and can be used to clean all garden tools, pots and other items to keep from spreading disease from plant to plant.
• Prepare the new pot where the cutting will be planted. The pot should be cleaned with the 10 percent bleach solution.
• Use high-quality, sterile potting mix, vermiculite, perlite or sand as the rooting medium. The rooting medium should be well drained, but moist.
• 

  Take the herbaceous cutting just below a leaf node. Photo courtesy Purdue Universtiy

  Take cuttings only from healthy, actively growing plants.

• The cutting should be 2- to 6-inches long. Make the right-angle cut below where a leaf is attached to the stem, called the leaf node.
• 

  Cut large leaves in half on herbaceous cutting to reduce moisture loss. Photo courtesy Purdue University

  Remove one-third to one-half of the leaves and any flower buds from the cutting. If the leaves that remain are large, cut them in half. By removing leaves and reducing their size, you reduce the cutting’s loss of moisture.

• Dust the lower inch of the cutting in a rooting hormone, available at garden centers. Some have a fungicide in the mix and some are just a straight rooting hormone. A fungus that causes dampening off can destroy some cuttings.
• Use a pencil, screwdriver or your finger to make a hole in the rooting medium.
• Insert the cutting in the hole. You can place more than one cutting in a pot. Gently press the soil around the cuttings.
• Place a clear plastic bag over the cutting and the pot, making sure the plastic does not touch the plant. Use toothpicks, bamboo stakes or chopsticks to keep the plastic away from the plant, if needed.
• Place the pot out of direct sunlight, but in a bright, warm spot.
• Check the pot every few days for soil moisture and to shake out the condensation that forms in the plastic bag.
• 

  You can place more than one herbaceous cutting in a pot filled with a sterile potting medium. Photo courtesy Purdue University

  After a two weeks, check to see if the plant has rooted by gently pulling on it. If there is resistance, the cutting has likely rooted. If not rooted, check again in a week.

• When the cutting has rooted, vent the plastic bag for a few days.
• Transplant the cutting to its permanent pot and move to its new location.

An herbaceous cutting is not the only type for propagating plants. There also are softwood, hardwood, leaf and root cuttings.