Roses are all the rage!

Posted by: Alison O'Connor, Larimer County Extension

I feel that roses tend to polarize people--some think they are amazing and wonderful garden plants (me!) and others feel they are too "needy" and hard to grow. I've had a love of roses my entire life, primarily because my Grandpa Stoven was an avid rose grower, and my dad has followed in his steps. Growing up in Minnesota, roses were not for the faint of heart. And to top it off--Grandpa Stoven grew hybrid teas, which are the ultimate Prima Donna of plants. His favorite was 'Peace', a tribute to the end of World War II and a beautiful bloom.

Peace hybrid tea rose (photo courtesy of Jackson and Perkins Roses)

Most of you know that my patience to baby plants is thin, so hybrid tea roses don't grow in my garden. My philosophy is that if you can't thrive on neglect, you're not a plant for me. But I do have several shrub roses, which I find to be easy to maintain, bloom profusely, and have little (if any) insect and disease problems. They really are easy to grow!

And yes, I know that Japanese beetles are munching their way across Colorado's Front Range, as far south as Pueblo. Roses are one of their favorite hosts, but our state entomologist, Dr. Whitney Cranshaw is evaluating roses to determine if there are cultivars that are less tasty to the hungry beetles. He's been studying this for a few years and has some promising results. For those in infested areas, I realize roses are not going to be at the top of your list, but hand picking can be very effective. Or pick and feed to chickens--they love to munch Japanese beetles and will eat them faster than you can pick them.

Chickens adore Japanese beetles (photo courtesy of New England Habitat Gardening Blog)

Larimer County Master Gardener, Roger Heins, is our rose expert, so I consulted him to see what he would recommend if someone wanted to plant roses. His own garden has dozens of specimens, plus he's been active in the rose demonstration garden at Treasure Island in Windsor. Here's our top recommendations:

Above and Beyond climbing rose (Rosa 'ZLEEltonStrack' PP24,463)
I absolutely adore this rose. And yes, it's a climber, so it needs some support. But what I've found after three years in the garden is that it just needs a little training in the spring and mid-summer. My dad is growing this in his Zone 3B garden north of the Twin Cities. This past winter it had very little dieback and had a magnificent bloom set in early summer.

Above and Beyond in full bloom in June

I have seen zero disease and zero insects, and it's super cold hardy. Height can reach 10 feet, so make sure you give it space! The apricot-flowers bloom in clusters and look like a double flower. It will bloom again later this summer, but the foliage is so clean that's it's just a beautiful plant any time of year. I did quickly snip off the spent blooms, not paying attention to the "rule" of pruning back to five-leaflets.

Above and Beyond in mid-July

Paint the Town shrub rose (Rosa 'BAItown' PP18,060)
Paint the Town is cute as a button, since it's a petite shrub rose that doesn't know when to stop blooming. I have this in my front, west-facing yard, and it gets very little (if any) irrigation. The red blooms cover the shrub all summer and stay a good red, even with the intense sunlight. Topping out in height at four feet (and about the same width), this rose can fit in small spaces if you need some color. The foliage is very dark green and I have seen zero disease issues. My brother has propagated this plant for years at Bailey's and it's on the top of his list too, since he doesn't see any disease issues in the greenhouse. In the photo below, it's planted next to hummingbird carpet, a 'Blonde Ambition' grass, and hopflower oregano. As you can see, it's just a bit taller than each of those. You can remove the spent flowers, if you wish.

Paint the Town shrub rose

Paint the Town flower bloom (just past peak)

Strike it Rich grandiflora rose (Rosa 'Strike it Rich')

Roger said this rose is performing amazingly well in multiple locations, so it's on the list. A grandiflora rose, the blooms are larger (about 4" tall) and have a spicy-sweet fragrance. The blooms are a beautiful orange with hints of pink. Introduced back in 2007, this rose has been a garden favorite for over a decade. Don't shy away from grandifloras...they can replace those high-maintenance hybrid teas with less work. And this rose is very cold hardy too.

Strike it Rich rose (photo courtesy of Destinations, Detours, and Dreams)

Golden flowers make this rose a must for your garden (photo courtesy of Edmunds Roses)

Sunrise Sunset shrub rose (Rosa 'BAIset' PP16,770)

There must be something in the water at Roger's house, because his Sunrise Sunset roses are breathtaking...and big! (Roger tends to both fertilize and water, which might be why his are superior to mine.) This non-stop summer bloomer has bright pink blooms that fade to a paler pink as the blooms age. This plant is truly a show stopper. Cold hardy, disease resistant, clean foliage--what more can you ask for in a rose? 

Sunrise Sunset rose (photo courtesy of Easy Elegance)

Bloom for Sunrise Sunset rose (photo courtesy of Easy Elegance)

Drop Dead Red floribunda rose (Rosa 'WEKcharlie' PP22571)

Described on one of the grower's websites as "jaw-droppingly delicious red", you can envision the bloom before you see the photo. Roger states that this is a fantastic red, especially with the dark green foliage. And it's a red that stays red throughout the entire bloom life. As a floribunda, it will produce clusters of flowers. But if you lust for a good red (like finding the perfect nail polish red), try Drop Dead Red.

Drop Dead Red floribunda rose (photo courtesy of Spring Hill Nurseries)

Obviously there are many roses out there that do well in Colorado gardens. What are some others you love? 

Battling Japanese Beetles

Posted by Lisa Mason, Arapahoe County Extension

If you live in certain parts of the Denver Metro area, you are probably very familiar with this pest. Littleton and other parts of Denver are inundated with this insect starting around mid-June.

Japanese beetle population levels in Colorado. Source: Colorado Department of Agriculture

This invasive beetle has two unique challenges: 1.) Japanese beetles cause damage during the larval/grub stage in turf grass, and adults cause damage by feeding on a variety of landscape plants and trees, and 2.) adult beetles feed on blooming flowers at the same time pollinators and beneficial insects are pollinating those flowers, which limits control options.

Japanese beetles were first introduced in the United States in 1916 and has spread throughout the US via nursery stock. The beetle was brought to Colorado in the 1990s but only recently have populations grown considerably. The larval stage feeds on the roots of turf grass, and the adult beetles feed on vegetation, including popular plants such as roses, crabapples, Virginia creepers, and linden trees. They can feed on over 300 plant types.

Japanese beetle life cycle. Source: University of Minnesota

A Japanese beetle larva. Source: David Cappaert, Bugwood.org

An adult Japanese beetle. Source: David Cappaert, Bugwood.org

You won’t see adult Japanese beetles appear until around mid-June, but now is the time to start planning for their return. Here are some things you can do:

For now and longer-term:

• Keep your plants as healthy as possible. A healthy plant will be able to sustain more damage. Practicing good cultural care will help reduce the stress on your plants.
• Keep turf as healthy as possible, too. A strong root system will be able to tolerate more feeding from grub.
• We are providing a perfect environment for Japanese beetles: well-irrigated turf provides their habitat and a wide variety of plants provides their diet.
• Consider planting other cultivars or plant varieties in the landscape. Research which cultivars are not susceptible to Japanese beetles.
• Be creative with plant selection! Evergreens, annuals, perennials, some vegetables, and many tree varieties are not susceptible to the beetle.
• Research your options for biocontrols and pesticides.
• Choices can be limiting depending on if pollinators are foraging on the same flowers that the Japanese beetles are feeding on. Pollinator-safe options include Bacillus thuringiensis var. galleriae (marketed as beetleGONE!, beetleJUS!) and chlorantraniliprole (marketed as Acelepryn SC).
• Look for plants that do not produce flowers or their flowers bloom at a different time than when the adult beetles are active. For example: crabapple trees bloom in the early spring when adult beetles are not active and other treatments may be an option.
• Remember the label is the law! If you chose to apply pesticides, the directions must be followed exactly.
• For a complete list of control options on foliage and turf and how they affect pollinators, see the Japanese Beetle factsheet.

When the beetles arrive:

Hand picking Japanese beetles off roses. Source: Lisa Mason

• Hand-pick Japanese beetles to your hearts content! You can squish them or dump them in a bowl of soapy water. This effort may seem tedious, but keep in mind each female beetle can lay 40-60 eggs. Hand-picking will also reduce the volatile attractants produced by plant wounding.
• Think twice before using Japanese beetle traps. Research shows that traps can attract more beetles to the area. As they fly towards the trap, they may find new food sources along the way. If you choose to use traps, place them at least 30 feet from any vegetation that the beetles will eat.
• Make sure you have grubs in your turf before treating the turf with products. Checking can save you time and money. Grub damage looks very similar to other turf issues. Try doing a “tug test”. If you tug on your turf and the grass pulls out of the ground immediately, then you have may have grubs that have been feeding on the roots. If the grass is rooted into the ground, you may have another issue.
• If you do have grubs, consider drying out the lawn when the grubs are active. They need well-irrigated soil to survive.

A native bee and Japanese beetles on a rose. Source: Lisa Mason

Are geraniums a plausible solution? Not likely. Research indicates that if Japanese beetles feed on geranium flowers (not leaves), they become paralyzed and rarely recover. However, geraniums are not a very favored host plant and if more attractive plants are nearby, such as roses, Virginia creeper, or lindens, then they would not visit the geraniums.  Also, if they do feed on geraniums, they mostly feed on the leaves, which are not toxic.

Japanese beetles are here to stay, unfortunately. With some longer-term landscape planning and persistent treatment efforts, we can try to disrupt the perfect environment we have created for them. 

More questions on Japanese beetle? The Japanese beetle factsheet is a great resource! You can also call your local county extension office.

Best of luck battling the beetles this summer! 

How Insects Survive Winter

Posted by: Jessica Wong, PhD Student, CSU Department of Bioagricultural Sciences and Pest Management

Insects have remarkable strategies for surviving Colorado winters. A few species migrate to escape the cold. The most well-known species to do this is of course the monarch butterfly. By now they have made their way to roosting sites in Mexico (or California in the case of monarchs from the Western Slope). The green darner, Colorado’s largest dragonfly, is another species that makes its way south before winter arrives. For the rest of the insects that can’t fly thousands of miles, they stay put right here in Colorado.

Migrating green darner dragonfly. Photo by Praveer Sharma, Flickr Creative Commons CC-BY-SA 2.0

Most insects have figured out how to survive our cold, dry, snowy, sometimes balmy winters. A few, like brown marmorated stink bugs and multicolored Asian lady beetles, will escape the cold by going indoors. Cracks and gaps in door and window frames are great opportunities for them, so make sure those are well sealed to prevent them from invading your house. The rest of the insects stay outdoors and go dormant. These insects produce their own antifreeze compounds to withstand temperatures well below 32 degrees. And they have genetic programming that prevent them from coming out of dormancy too early, which is handy on that 70 degree day in February.

Multicolored Asian lady beetles preparing to overwinter. Photo by Howard Russell & Christine DiFonzo, Michigan State University

Insects overwinter in different life stages – egg, larva, pupa, or adult – depending on species. Most species of aphids and crickets survive the winter as eggs. Aphid eggs can be found on trees and shrubs, and cricket eggs can be found in the soil. Japanese beetle and emerald ash borer are two serious pests that overwinter as larvae (also known as grubs). Japanese beetle grubs spend the winter in the soil under turfgrass, such as your lawn. Emerald ash borers overwinter in their galleries just under the bark of ash trees.

Aphid eggs on pine needles. Photo by Beatriz Moisset, bugguide.net

Japanese beetle larvae. Photo by David Shetlar, the Ohio State University

Emerald ash borer larva in its gallery. Photo by Howard Russell, Michigan state University

Black swallowtail butterflies survive the winter in their pupal (chrysalis) form, while another butterfly species, the mourning cloak, overwinters as adults. Bumblebees and yellowjackets also overwinter in the adult stage. Both bumblebees and yellowjackets are social insects with colonies in the spring and summer, but in the fall workers start to die and only fertilized queens survive through the winter. When spring finally comes all the insects break dormancy and resume their unique life cycles. 

Black swallowtail pupa. Photo by Donald Hall, University of Florida

Beauty is Only Skin Deep

Posted by Deana Wise, Broomfield County Extension

Beauty Is Only Skin Deep

        In our world, beautiful people are envied. They are viewed as being more successful, happier, and lead more interesting lives. In the insect world, some of the most beautiful are the most threatening to our urban landscapes. We seek to destroy them at all cost.

Fig. 1 Japanese beetle adult.

Photograph courtesy of David Cappaert/University of

Michigan and IPMImages.org.

          One example is the dreaded Japanese beetle (Popillia japonica). This metallic green pest with brown wing covers, white spots and distinctive antennae (Fig. 1) has been a major problem in the eastern U.S. for close to a century. The adults munch on a wide variety of plants (between 200-300) while the larval form feeds on the roots of grasses. This indiscriminate grazer can rid your garden of flowers, buds and leaves from Roses, Virginia Creeper, and American Linden among others. It has settled in Colorado.

 

Fig.2 Grub
Photo retrieved from  www.ent.iastate.edu

       The grubs are white with dark heads and the thorax has 3 pairs of well-developed legs (Fig.2). They are usually curved in a C shape and have a distinctive V-shaped rastral pattern (Hairs on the hind end). They feed on the roots of grasses, reducing the plant’s ability to absorb water. Heavily infested turf can be easily pulled up, revealing the grubs beneath.

          The adult emerges from the soil in June and feeds for 4-6 weeks. After mating, the female lays 40-60 eggs, 2-3” deep into the soil. The larva remains in the soil for up to 10 months (Fig. 3).   They prefer well maintained, damp turf. The eggs and newly hatched grubs can be damaged or killed by excessive drying of the soil. Older grubs simply move down deeper to survive. They are not affected by overly damp soils.



Fig.3  Japanese beetle lifecycle
Photo retrieved from www.extension.umn.edu

          Control of Japanese beetle can be achieved in various ways. One satisfying alternative is to pick the beetles off and deposit them into a container of soapy water or mineral spirits. If you don’t care for hand to hand combat, there are several insecticides labeled for both Japanese beetle stages.

The adults can be killed with various pyrethroid, permethrin, and Carbaryl products.  Neem products or Pyola (pyrethrins in canola oil) are botanical alternatives. As with all chemicals, follow the label and use caution when applying to plants where bees are present.

The grubs can be treated by several methods. Certain parasitic nematodes in the genus Heterorhabditis can be applied to the soil when grubs are present. Another popular biological control is Bacillus popilliae or milky spore. Insecticides include: imidacloprid, chlothianidin, and chlorantraniprole. As with any chemical, it is very important to follow the label.

For more information see fact sheet no. 5.601, Japanese Beetle.

http://www.ext.colostate.edu/pubs/insect/05601.html