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Category: Lawn and Garden

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Recent storms have caused damage to trees, landscapes, and homes across the country. Many trees are too large for homeowners to safely remove.  With over 50 fatalities yearly nationwide for professionals removing or pruning trees, the rate is much higher for people not trained in specialized tree work. Proper tools and equipment, as well as safety procedures, must be used.

Pruning initiates wound response by trees (compartmentalization), isolating microorganisms and insects to avoid further damage. Remove broken or damaged limbs, but not more than one-third of the branching system of any tree. If more than one-third of branches have been damaged, remove the tree. Cut limbs back to a lateral branch collar swelling, do not leave a stub. Do not paint or seal wounds, which should be allowed to heal naturally.

A fact sheet from Oklahoma State has more information: http://factsheets.okstate.edu/documents/epp-7323-managing-storm-damaged-trees/?fbclid=IwAR2Tz9N_LUO3ODoJnHk6VZEA1c-cqFkzqkiz2JXH8bU7smKVBtLXJINe9BA
NFG 5/31/2019

This season, many people are shopping for a perfect cut tree or live tree to decorate their homes.
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This season, many people are shopping for a perfect cut tree or live tree to Douglas fir treesdecorate their homes. Our local Christmas tree growers face many challenges to growing a perfect tree, an expensive and time-consuming process. A Christmas tree takes 8 to 10 years to grow to a good size, and there are many hurdles along the way. Trees must be planted properly in good soil, not too shallow or not too deep. It may take up to three years for a transplanted seedling to establish a good root system.
Insect pests and plant diseases can cause problems for Christmas tree growers. Phytophthora root rot is problematic on tree farms in many states. Phytophthora is a fungus-like organism, favored by wet, saturated soils with poor drainage. Roots in saturated soil may be stressed. The best management strategies for root rot are the purchase of clean healthy seedlings and proper site selection, because the best possible control is to avoid Phytophthora root rot to start.
There are other pests and diseases that attack Christmas tree species, such as needlecast fungi that cause spotting and discoloration of needles, and needle drop. Growers must scout their trees, apply fertilizer and pest control, trim to shape, and keep up with research on tree species and new varieties. Sales of trees, following the 10 years of nurturing, all occur yearly within a 4 to 6 week period! Our Christmas tree growers are dedicated agricultural professionals who love to see smiles on the faces of people who purchase and enjoy the trees that they grow!
Find a Delaware Christmas Tree Grower near you at: http://www.delawarechristmastreegrowersassn.com/
NFG 12/5/2016

Pumpkins are one of our favorite fall decorations, food sources, and animal feed sources in Delaware.
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Pumpkins are one of our favorite fall decorations, food sources, and animal feed sources inpumpkin-fruit-rot Delaware. Agro-tourism, including fall hayrides, pumpkin picking, and other activities are strong sources of farm income. Fruit rots caused by fungi and bacteria can diminish profits of farmers, especially in seasons with wet weather, high humidity and fluctuating temperatures.  Fruit rots also disappoint consumers who expect a purchased pumpkin to last a long time. Micro organisms can cause problems during storage post-harvest.  Avoid wounding pumpkins at harvest, during transit, and keep in a cool location. Wounds allow micro organisms to enter.
The fungus-like organism Phytophthora capsici has a very wide host range, including cucurbits such as pumpkin, watermelon, squash, and tomatoes, beans, and other vegetables. If a pumpkin develops a white powdery soft rot such as in the picture, it may be due to Phytophthora. Discard it in the trash, do not compost in gardens or use the seeds to start plants for next season. Phytophthora is not harmful to humans or animals, but secondary fungi can move in. The black specks in the picture show some secondary fungi that have started to grow on the affected area.
N Gregory 10/21/2016

BLS has been very damaging to red oaks in Delaware and the Mid-Atlantic states since the early 1990’s
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BACTERIAL LEAF SCORCH (BLS) of hardwood trees, shrubs, and herbaceous plants, is caused by the bacterium, Xylella fastidiosa, carried by small insects such as leaf hoppers and sharpshooters. BLS has been very damaging to red oaks in Delaware and the Mid-Atlantic states since the early 1990’s. Northern red oak and pin oaks under environmental stress are more susceptible. Symptoms include marginal discoloration or scorch of leaves in late summer or early fall, often with a yellow or dark band on the inside edge of the discolored area. Symptoms are similar to those caused by drought or root issues that interfere with flow of water and nutrients. Plants may not develop symptoms for a year or two after infection, but then thinning of branches occurs and trees die within 5 to 8 years.  Infection is confirmed with a lab test for a fee, so if confirmation is needed, please arrange to have samples tested by contacting the UDBLS Red Oak 2016 Plant Diagnostic Clinic. Please note that there is a $20 fee for BLS testing. To manage, maintain good tree vigor, and remove infected trees. A UD fact sheet has more info: http://extension.udel.edu/factsheets/bacterial-leaf-scorch/
NFG 8/30/2016

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2015 Fungicides and Bactericides Available for Home Use
An updated listing of fungicides, biorational products, and bactericides for home use in Delaware has been published. The listing is a compilation of products found at retail stores in the Newark, Delaware area in early June of 2015, not a recommendation. The label is the law, please read and apply agricultural chemicals according to the label. Correct identification of pests and diagnosis of disease should precede pesticide use.

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Nancy Gregory talking to new Newark residents
Nancy Gregory talking to new Newark residents

Ag Day was cool weatherwise, but a warm atmosphere for the crowds who came out to learn about and purchase plant, and see the other exhibits. It was a great day. I enjoyed being side-by-side with the Master Gardener Telephone and Diagnostics Team, and having Kayla help me at the Plant Diagnostic Clinic table!
Great to have student Kayla involved
Great to have student Kayla involved

MG Telephone and Diagnostics Team
MG Telephone and Diagnostics Team

 

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New Fact Sheet 2/25/2015 - Home Orchard Production - Apple, Pear, and Stone Fruit Disease Management - Nancy F. Gregory

Growing fruit in a backyard or home orchard can be rewarding or can be very frustrating, depending on disease and insect pests that may be present. While it is tempting to plant fruit trees and not apply chemical control measures, it is often impractical, and the resulting fruit crop may be disappointing or not result in any harvestable fruit. Various diseases affect fruit, and some are caused by fungi while some are caused by bacteria and viruses, so accurate examination and diagnosis is important. Disease development is dependent on the host, pathogen, and a suitable environment (mainly temperature and moisture). Controls may include preventative (protectant) fungicides, but availability and labels may vary for different states, and label directions must always be followed.
Fire Blight on PearImages: Fire Blight on Pear and Peach Leaf Curl
The most common tree fruits grown in home orchards are apples, pears (European and Peach Leaf CurlAsian), and stone fruits (peaches, nectarines, plums, apricots, pluots, and cherries). Apple trees are commonly affected by fire blight, apple scab, fruit rots, rusts, and powdery mildew. Fire blight is a common problem in pears. Stone fruits are affected by peach leaf curl, bacterial spot, brown rot, scab, and leaf spot.
Read the rest of the fact sheet, including recommendations at the following web site: http://extension.udel.edu/factsheet/home-orchard-production-apple-pear-and-stone-fruit-disease-management/
 
 
 
 

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Spotted Lanternfly Adult
Spotted Lanternfly Adult

The spotted lanternfly, a poor flying but strong jumping moth-like pest that attacks grapes, apples, tree of heaven (Ailanthus), and other hosts has been found in Berks County Pennsylvania. The inch long insect is a potentially devastating pest. Please see the PA Department of Agriculture web site at: http://www.agriculture.state.pa.us/
The Spotted Lanternfly (Lycorma deliculata), an inch-long black, red and white spotted pest, is native to China, India, Japan and Vietnam. It’s an invasive species in Korea, where it has attacked 25 plant species which also grow in the U.S.. In the U.S. it has the potential to impact grape, fruit tree and logging industries. The pest attacks many hosts including grapes, apples, pines, stone fruits and more. This time of year, look for adults and egg masses on trees such as Ailanthus, and please collect samples and report any suspect finds to your  local Cooperative Extension office or Delaware Department of Agriculture.
Spotted Lanternfly Egg Masses on Tree Bark
Spotted Lanternfly Egg Masses on Tree BarkNFG 11/4/2014

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Fringe tree, Chionanthus virginicus, Image L V Gregory
Fringe tree, Chionanthus virginicus, Image L V Gregory

On October 14, 2014, the USDA Systematic Entomology Laboratory (SEL) at the Smithsonian confirmed partial adult and larval specimens recovered from a white fringetree (Chionanthus virginicus) as emerald ash borer (EAB) (Agrilus planipennis Fairmaire). EAB larvae and a partial adult specimen were collected from four white fringetrees up to 20 miles from one another in the Dayton, OH area. D-shaped exit holes and fully developed galleries in wood were identical to those caused by EAB.
Based on these findings, APHIS PPQ is conducting studies whether EAB is able to complete its lifecycle on white fringetree as a host, which will take several months. APHIS is also revisiting research on whether other members of the Olive family can serve as hosts of EAB and whether this is a local phenomenon.  APHIS will engage national, state, and industry partners as part of the regulatory decision making process should APHIS officially declare white fringetree as an EAB host and the plant and its parts as regulated articles under the regulations, quarantine, and detection aspects of the EAB program.
White fringetree is in the olive family, as is the genus Fraxinus (ash). Other members of the olive family, including lilac and privet, were tested, and are not considered suitable hosts for EAB.  Further study and evaluation of white fringetree’s suitability as a host will be undertaken. White fringetree is native to the United States and grows wild from New Jersey south to Florida and west to Oklahoma and Texas. It is a popular ornamental tree that has been planted in other parts of the country.
10/23/14 NFG

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Phytophthora Resistant Plants

Phytophthora root rot OlsonPhytophthora root rot, a soil borne disease caused by a fungus-like organism, is a widespread problem which can affect many woody and herbaceous landscape plants. Azalea, holly, rhododendron, and juniper are the most frequently affected plant groups in the eastern landscape. Submit a sample including roots to the Plant Diagnostic Clinic and it can be tested for Phytophthora. An infested site should not be replanted with susceptible hosts. Increase drainage and plant a more resistant shrub or tree. The best control for Phytophthora is to avoid getting it started in the first place. Phytophthora is favored by planting susceptible species and cultivars in poorly drained soils, or by overwatering in sites with adequate drainage. Once a Phytophthora problem is established in a landscape site, the best option is to remove the affected plants and replace with resistant species. Some good choices include Clethra alnifolia (summersweet), Itea sp (sweetspire), Physocarpus opufoliius (Eastern ninebark), and Leucothoe fontanesiana. Examples suggested by extension agents in North Carolina include Nandina, Chinese holly (cultivars including 'Rotunda', 'Dwarf Burford' and 'Carissa'), liriope, Indian hawthorn, and Camellia sasanqua cultivars (Camellia japonica is highly susceptible). The rhododendron hybrids: ‘Caroline’, ‘Martha Isaacson’, ‘Professor Hugo de Vries’ and ‘Red Head’ are considered resistant. In addition, the azalea cultivars 'Formosa', 'Fred Cochran', 'Fakir' and 'Corrine Murrah' are considered highly resistant. Other resistant azalea cultivars include Rhododendron poukhanese, ‘Formosa’, ‘Fakir’, ‘Corrine Murrah’, 'Merlin', 'Hampton Beauty', 'Higasa', 'Pink Gumpo' and 'Delaware Valley'. Susceptible cultivars include 'White Gumpo', 'Hinodegiri', 'Hershey Red', 'Coral Bells', 'Pink Pearl' and 'Hino Crimson'. Susceptible cultivars are the most widely planted, due to desirable horticultural characteristics. Resistant hybrids are not immune to disease, but more tolerant. Chemical control is generally not practical for the homeowner, and involves a drench or injection by a certified applicator.
NFG 10/2014