By GENE FOX
Extension agent, consumer horticulture

Everyone notices the Bradford or Callery ornamental pear trees in the spring. In almost every neighborhood the ornamental pear trees adorn the streets and driveways with their showy white blossoms as one of the first bloomers in the spring season. Right now, however, the ornamental pears are being recognized for unsightly dead spots throughout their canopy. In the early spring, I chalked this up to winter burn from back-to-back cold snaps we had in the beginning of April, but then it kept showing up. I did what any good extension agent would and began to research problems with ornamental pears. There are two notable and widespread issues with the ornamental pears: fire blight and cedar quince rust.

Fire Blight

Fire Blight is a bacterial disease that is typically seen in fruit tress such as apples, pears and plums. It is for this reason that many do not grow fruit trees commercially in the area. Fire Blight is also found in ornamental pears. There is a characteristic “Shepherd’s Crook” on the ends of affected branches: upon close examination the branches are dead and appear to be brown or black as if they had been scorched. The fruit will be desiccated and looks as though it has been burned on the branch.

Fire Blight can be controlled in the commercial orchard using sprays, but chemical control is not practical in an ornamental setting. Pruning is another tool that can be used to combat fire blight. In the dormant season, prune the branches just below the scorched-looking canker. In the growing season, prune a minimum of 10 inches below the canker. Whenever pruning diseased branches, it is imperative to sanitize pruning equipment in between cuts. If left untreated, the cankers eventually move to the main vascular system of the tree, resulting in a total loss of the tree.

Cedar-Quince Rust

Cedar-Quince Rust is a fungal disease that can mask itself as fire blight by displaying the same characteristic “Shepherd’s Crook” and dead branch ends. However, the scorched looking cankers will not be present. Another symptom that distinguishes the two issues is the presence of the fungal fruiting body on the tree fruit and on the branches as seen in the pictures below. Cedar-Quince Rust requires two hosts to complete its life cycle, the Bradford Pear, Hawthorn or Quince tree and a cedar tree. This fungal disease will not kill the tree in most cases but will cause them to look unsightly. This disease favors wet. Control is not recommended by the Plant, Disease, and Insect Clinic for ornamental pears grown in a residential setting. There are fungicides available for commercial growers and nurseries.

Management

A little known fact about Bradford Pears is they are considered an extremely invasive species across the southeastern U.S. They were bred to be showy, quick growing and sterile. They are very showy bloomers and quick growing, however, this has resulted in a very brittle structure and soft wood. The problem here is that once they get a little size on them the inevitable summer thunderstorm comes along and blows the branches just enough to break whole section of the tree out. They have been found to be reproductive as well, but they do not produce Bradford pears, they produce a very quick growing, thorny, invasive tree that quickly inhabits a new area, choking out our native trees. As these trees are dying out or splitting, plans should be made to replace them. There are several alternatives to the Bradford Pear that can be found at N.C. State’s “Going Native” website.

In the Blacklands area (Beaufort, Hyde, Tyrrell and Washington Counties), call Gene Fox, consumer horticulture agent at the Beaufort County Cooperative Extension Center, at 252-946-0111. To keep up with information and workshops, like the Blacklands Area Horticulture Facebook page or visit the Beaufort County Extension website at beaufort.ces.ncsu.edu/. You can also follow Gene Fox @Foxplantguy on Twitter.

Additional Helpful Links:

• extension.tennessee.edu/publications/Documents/W289-F.pdf
• www.clemson.edu/extension/hgic/plants/landscape/trees/hgic1006.html
• www.ncsu.edu/goingnative/howto/mapping/invexse/bradfor.html
• www.newbernsj.com/article/20140606/Opinion/306069833

The Extension Master Gardeners are available through the hot line to answer your questions concerning lawns, vegetables, trees, ornamentals, fruits, plant problems and diseases, pests, soil and many other horticulture issues relating to gardening in North Carolina. The Hot Line telephone number is 252-946-0111 and the hours are Mondays and Wednesdays from 10 a.m. to noon. You can leave a voice message at that number or email the Master Gardeners your question at beaufortcomg@gmail.com and a volunteer will return you call on the next hot line work day.

 

July Gardening Calendar

Avoid gardening between the hours of 10 a.m. and 4 p.m. to minimize the stress to the plants and to the gardener.

Lawn Care
• Fertilize warm-season grasses like Bermuda, Zoysia and St. Augustine, if you haven’t already done so.
• A third of the growth should be removed when mowing warm season grasses.
• Try to change direction when mowing your lawn. This will help strengthen the roots system and expose different sides of the plant to sunlight.

Fertilizing
• Continue side-dressing your garden vegetables.
• July is the last month to fertilize landscape plants.
• Now is a good time to take soil samples from your lawn. Soil boxes can be picked-up at the county extension office.

Planting
• Vegetables to be planted in July: brussel sprouts, collards, beans, carrots, tomatoes and pumpkins.
• Start broccoli, cabbage and cauliflower plants in peat pots to be transplanted in mid-August.
• Now is a good time to repot overgrown houseplants.

Pruning
• “Bleeder” trees like maple, dogwood, birch and elm can be pruned this month.
• Outgrown hedges can be pruned.
• Pinch off garden mums till mid-July.
• Narrow-leaf evergreens like junipers and arborvitaes can be pruned.
• Fruiting canes of raspberry and blackberry can be cut down to ground level after the harvest.
• Remove faded flowers on flowering perennials to encourage a second flowering.
• The dieback on hybrid rhododendrons, azaleas and blueberries can be pruned out.
• Lastly, don’t forget to pinch your chrysanthemums to encourage branching.

Spraying
• Watch shrubs for the following insects: bag worms, leaf miners, aphids, spider mites and lace bugs.
• Japanese beetles if needed.
• Use recommended herbicide to control poison ivy and honeysuckle if desired.
• Start fungicide treatment on tomatoes, which show signs of blight.
• Continue with rose spraying program.
• Continue fungicide program for fruit trees and bunch grapes.
• Spray the following vegetables if insects are observed: cucumber (cucumber beetle), squash (aphids), tomato and eggplant (flea beetle). Pesticides should be used sparingly — use only when needed and always follow the label.

Other Activities
• Prune any branches damaged by the recent storms.
• Fruit trees that bore no fruit like peach, plum and apple can be pruned as if they were dormant. This will allow more sunlight in and prepare the plant for the next year.

Tips on Shopping at the Farmers Markets
• Fresh green beans should “stick” to a T-shirt.
• The stem ends of fresh tomato should have a white color.
• Smell may not always be a clue to a cantaloupe’s freshness. Older varieties of cantaloupe have a great smell, however, newer varieties may not have the same smell but taste just as good. No cantaloupe should smell bad. A bad smell is a sign of bacteria and spoilage.