Cornell Cooperative Extension of Jefferson County’s
Horticulture September-October2015
2015 Floriculture Field Days Black Swallowtail Caterpillar Elm Disease Persists 1
2015 Floriculture Field Day
Horticulture Your resource for gardening, lawn care, vegetables, trees, pests, and more from Cornell Cooperative Extension Association of Jefferson County.
Vol. 18 Issue 5
Table of Contents 2015 Floriculture Field Day ..........................2 Floriculture Field Day Photos………….3 & 4 Gardening Trends ............................................5 Be on the Look Out! Oak Wilt ....................6 Black Swallow-Tail Caterpillar ...................6 Elm Disease Persists .....................................7 2015 Annual Meeting ......................................8 Calendar of Events .........................................8
By Sue Gwise, Horticulture Educator The 2015 Floriculture Field Day was held at Cornell University in August. This annual event gives retailers, writers, and educators a chance to see the new offerings of flowers for the next season. New varieties of flowers are trialed in gorgeous gardens that were at their peak during our visit. Innovative displays and container gardens were showcased. Below are just a few of the things that were impressive. To see these photos in color, view the Horticulture Newsletter at http:// ccejefferson.org/gardening. Above photo: Wacky Wigs— Succulents served as hair on these whimsical pots.
Mission Statement
Cover photo: This 7 foot+, tiered vegetable garden had a cherry tomato in the top pot and lettuce in the center pot. The bottom pot included a bell and hot pepper, eggplant, green beans, chard, edamame, carrots, kale, and cucumber!
Cornell Cooperative Extension Association of Jefferson County educates youth, families, farmers, and communities using researchbased knowledge for practical application and lifelong learning.
Building Strong & Vibrant New York Communities Cornell Cooperative Extension is an employer and educator recognized for valuing AA/EEO, Protected Veterans, and Individuals with Disabilities and provides equal program and employment opportunities; NYS College of Agriculture and Life Sciences, NYS College of Human Ecology, and NYS College of Veterinary Medicine at Cornell University, Cooperative Extension Associations, county governing bodies, and US Department of Agriculture cooperating. Please note that neither Cornell Cooperative Extension of Jefferson County nor any representative thereof makes any representation of any warranty, express or implied, of any particular result or application of the information provided by us or regarding any product. If a product is involved, it is the sole responsibility of the User to read and follow all product labeling instructions and to check with the manufacturer or supplier for the most recent information. Nothing contained in this information should be interpreted as an express or implied endorsement of any particular product or criticism of unnamed products. With respect to any information on pest management, the User is responsible for obtaining the most up-to-date pest management information. The information we provide is no substitute for pesticide labeling. The User is solely responsible for reading and following manufacturer’s labeling and instructions.
Petunia hybrid- Supertunia Picasso in Burgundy (Proven Winners). Allan Armitage points out that because ‘supertunias’ have smaller flowers they are more resilient than standard petunias. 2
Great ideas all around! Pallets were used to create vertical gardens.
At least 100 bedding plant and flower varieties being trialed for 2015 and 2016 were on display. Coleus—Solenostemon scutellaroides ‘ColorBlaze Apple Brandy (Proven Winners).
Master Gardeners Dorothy Reynolds and Carol Wardwell pose with Hibiscus moscheutos ‘Luna Red’ (Prides Corner Farms).
Bees were working Bidens ‘Beedance Painted Red’ (Suntory).
‘Beedance Painted Red’ Bidens work best as a mass planting or in hanging baskets. 3
Zinnia—‘Zahara Red’
Petunia milliflora—‘Double Surfinia Summer Double Salmon’ (Suntory)
Calla Lily—‘Golden Chalice’ (Longfield Gardens)
Caladium—‘Fireworks’ (Classic Caladiums) 4
Gardening Trends—2015 Floriculture Field Day By Sue Gwise, Horticulture Educator One of the featured speakers at the Cornell Floriculture Field Day was Allan Armitage. You probably know him from his books, HGTV, or his signature hat. We were treated to his presentation on trends in edible plants. According to Dr. Armitage, “The garden of tomorrow is the deck,” and current trends reflect this.
Add some annuals to that pot and you hit upon another trend: combining vegetables and flowers in one pot. In addition to more container options, increased species and varieties will be available in herbs and Asian vegetables. Dr. Armitage is quick to stress that fun is important to today’s gardener. As a result retailers will be offering interesting and innovative plants. How about grafted tomatoes? The tomato variety of choice is grafted onto a disease resistant and vigorous rootstock. The effect is a tomato plant that is over 10 feet tall. ‘Ketchup and Fries’ is a tomato that is grafted onto a potato. The plant produces both of these staples on a six-foot tall plant that can be grown in a container or directly in the ground. Potato towers include seed potatoes, straw, and fencing. Plug the potatoes right into the straw ‘tower’ for an instant and compact garden. Look for curious fruits like ‘razzle berries‘ and the ‘hula berry’ which is like a ‘reverse’ strawberry. The berry is white and it is speckled with red seeds!
Vegetables are being bred to be container friendly. Families today want fresh vegetables but don’t want to deal with large garden plots. Look for short, compact, prolific, and sturdy ‘patio’ vegetables. ‘Rapunzel’ produces long clusters of cherry tomatoes on grape-type vines. ‘Big League’ has beefsteak-sized fruit on a short, stocky plant. Growers are also producing plant plugs that include two to three types of vegetables. Just transplant them into a large pot for an instant garden! Another big trend is ornamental vegetables that have a dual-purpose: decoration and food. For example, eggplants have attractive foliage and the fruits come in a myriad of colors and shapes. 5
As the disease progresses the leaves begin to wilt from the top downward. Leaves begin to drop and the tree is defoliated within weeks. Trees in the white oak group (white and bur oak) die slower but in a similar pattern as red oaks and also exhibit marginal scorch on the leaves. Live oaks show different symptoms (which I won’t go into since live oaks do not grow in NNY!).
Be On the Lookout! Oak Wilt
Other diseases like bacterial leaf scorch, anthracnose, and oak decline all look similar to oak wilt. If you are concerned about an oak tree bring a sample into your local Extension office for correct identification. The sample should include leaves and a twig or small branch.
By Sue Gwise, Horticulture Educator
Once a tree is infected with oak wilt there is no control or cure. Research is underway to develop effective fungicides. You can protect your trees by preventing wounds from lawnmowers, weed trimmers, and construction. Pruning also creates wounds, so prune only during the dormant season (winter time). If pruning needs to be done during the growing season due to weather damage make sure to apply a wound dressing to prevent transmission of the disease.
Oak wilt is an aggressive fungal disease that has killed thousands of oak trees in the Eastern United States. It is believed to be an exotic disease, but it has only been found in the U.S., so its origins are basically unknown. It was first identified in 1944 and its occurrence has been ramping up since the 1980’s. The disease is concentrated from the Great Lakes region south to Tennessee and west to Oklahoma and Texas. In New York State oak wilt was found in Schenectady County in 2008. As far as we know it has not spread in New York beyond this one and only infection site.
Black Swallow-tail Caterpillar
Oak wilt attacks all species of oak, including live oak (a western and southern species), pin oak, black oak, and our native red and white oaks. Red oaks appear to be particularly susceptible—mortality can occur within three weeks of infection. White and bur oaks appear to have some resistance and will succumb more slowly, after one to three years. Oak wilt is spread in two ways. If a tree is infected the disease can move to an adjacent tree through root grafts. So if one tree in a group is infected it is likely the others are too. It is also spread by insects. Spore mats growing under the bark of an infected tree causing the bark to split open. A strong odor emitted from the spore mat attracts sap beetles that then can spread the disease from tree to tree. Any wound to an oak tree, whether it’s from pruning, construction, or storms is a potential infection site. Oak bark beetles are additional vectors.
By Sue Gwise, Horticulture Educator This black swallow—tail caterpillar is hanging out in a carrot patch. It is bright fluorescent green in color with black stripes that are topped with yellow spots—one of the more striking caterpillars found in late summer. Also known as the ‘parsleyworm,’ it feeds on parsley, celery, dill, fennel, wild carrot, and carrot. Since the female only lays a few eggs in one place it does not do much damage to plants. The adult black swallowtail butterfly can be up to 3.5 inches wide. The wings are dark brown with two rows of yellow spots. Once a common species in the Northeast, it is becoming less so in butterfly counts.
Symptoms of oak wilt vary slightly depending on the type of oak. In the red oak group (northern red and pin oaks) rapid wilting and browning develops along the edges of the leaves. The upper crown of the tree may exhibit an off-green color. This usually begins in late June to early July. 6
Since the disease is a fungus it produces spores which are spread by the breeding activities of the elm bark beetle or by elm-to-elm root grafts. Preserving an elm tree requires both expensive and heroic measures. According to the Cornell Pest Management Guidelines for Trees and Shrubs, all of the following must be done: Eliminate all potential beetle-breeding elm material within 700 feet of the trees to be protected. Make dormant applications of an appropriate insecticide to control elm bark beetles. Trunk injections of an appropriate fungicide. Prune out any infected branches.
Elm Disease Persists
By Sue Gwise, Horticulture Educator
Disease resistant elms are an option. If you have one of these hybrids, or plan to plant one, keep in mind that they are only resistant to Dutch elm disease—they are not immune and can develop the disease. Elm cultivars with Asiatic origins tend to be the most reliably resistant, but they do not have the poeticized vase shape of the American elm.
There was a time in the recent past when the American elm lined the streets of eastern towns and cities. Favored because of its graceful, arching form, the elm can be found in most city-scape photographs of the mid-20th century. In fact, I have a photograph that was taken in Watertown in the early 1950’s. The view looks south on Washington street and features the Roswell Flower monument. In the background, American elms arch over the length of the street.
Of course there are a few large elm trees throughout the U.S. that are thriving with no signs of disease. Researchers are interested in these trees in hopes that they may have some innate resistance to Dutch elm disease. Breeding programs and control measures continue to evolve in hopes that a truly disease-free American elm with a classic shape can be developed.
Unfortunately, these “picture postcard” settings no longer exist in any American city. All of those elms were wiped out by a fungal pathogen called Dutch elm disease. The American elm still exists, but it only grows to about 30 feet tall before succumbing to a disease that is still active and has foiled control and breeding measures for 80 years.
We want your harvest photos!
Elms in Europe mysteriously began dying after World War I. In 1922 the previously unknown fungus, Ophiostoma ulmi, was identified as the cause. It was given the common name of Dutch elm disease because most of the original research done on the disease was conducted in the Netherlands. It was first confirmed in North America (Cleveland, Ohio) in 1927. It was found in New York in 1933. It is believed that the disease originated in Siberia and traveled west on trade routes. Dutch elm disease lives in the active xylem tissue of the tree. The xylem is responsible for water movement within trees. Dutch elm disease kills by essentially plugging the xylem cells so they cannot move water and nutrients.
To encourage home gardening, Cornell Cooperative Extension of Jefferson County will have a contest on our Facebook page at www.facebook.com/ccejefferson We would like to have home gardeners say ‘thank you’ to their gardens and submit photos of their harvests, including fresh produce, canned goods, or even dishes that you created with foods from your garden. The contest will run from August 30 to September 30. First, second, and third prizes will be awarded based on how many ‘likes’ each photo receives. Visit our Facebook page for complete details and enjoy your harvest!
One of the first symptoms of infection is called “flagging” and it usually becomes noticeable in late summer. One or two branches within the tree canopy will suddenly wilt and then turn yellow. The tree will usually die within a couple of growing seasons. 7
Cornell Cooperative Extension Association of Jefferson County 203 North Hamilton Street Watertown, NY 13601-2948
Non-Profit Organization US POSTAGE PAID Permit #242 WATERTOWN NY
Calendar of Events September-October 2015 September 22, 10:00 AM Master Gardener Meeting
September 23
First Day of Autumn
September 24, 5:30PM-7:30PM
Let’s Learn Pressure Canning Basics
September 28, 6:00 PM Junior Master Gardeners
October 1, 6:00 PM
Presentation on GMO’s Jefferson Community College
October 10, 10:00 AM-4:00 PM Autumn Fest
Minna Anthony Common Nature Center, Wellesley Island
October 26, 6:00 PM
Junior Master Gardeners
October 27, 10:00 AM
Master Gardener Meeting
8
203 North Hamilton Street, Watertown, New York 13601 Phone: 315-788-8450 Email:
[email protected] Web: ccejefferson.org www.facebook.com/ccejefferson