Weather reminder: If Prince William County Schools close early or are closed due to inclement weather, classes and programs will be cancelled and will be rescheduled. Please call 703-792-7747 for more information.
Staff and volunteers with the Prince William Cooperative Extension’s
Environment and Natural Resources program provide educational programs for individuals and business to implement sound practices producing aesthetically pleasing landscapes that have minimal negative impacts on the environment. Programs include:
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The Environment and Natural Resources team and Master Gardener Volunteers of Virginia Cooperative Extension answer many questions throughout the year. Below are some of our most frequently asked questions for this time of year.
If you have additional questions, contact our Extension Horticultural Help Desk at 703-792-7747 or
It is not too late to participate in the BEST Lawns program. For a $25 fee, we can measure and sample your lawn, develop a nutrient management plan tailored to your lawn and provide information to help improve the problems specific to your lawn. For more information visit BEST Lawns on the Prince William County website.
If you have warm season turf, this is their time of year. Adequate moisture is essential for their health and growth, but most warm season grass does not need to be watered in a home lawn setting.
If you have cool season turf, you have to make the decision to either water for the summer or let the grass go dormant. If you choose to water to prevent dormancy, cool season turf needs 1 inch of water per week. Dormant grass will lighten in color. Most of the time, they can handle the extremes of summer and will re-green with autumn rains. Dormant cool season turf can survive on ½ inch of water every 2-3 weeks during periods of exceptionally high temperatures.
Watering should be deep and infrequent. Because some soils can’t handle one inch of water all at once with causing run off, you may have to apply water every 3-4 days to get one inch’s worth of water in a week. Watering lightly every day is NOT good for your grass as it produces weak shallow roots. Water should be done as early in the morning as possible. This will lessen losses from evaporation and won’t encourage disease. Make sure you’re mowing high for the summer. That extra height makes a big difference in soil temperature and moisture retention.
If you lose grass to the summer or are looking for better drought tolerance in your grass, you may want to consider over seeding with more resistance grass varieties. Contact our office for type and varieties recommendations.
Drought can weaken trees over time. With continuing droughty summers, many trees are starting to see the results of under watering in past years. Weakened trees become more prone to disease and insect damage. Trees and shrubs need an inch of water a week under the canopy out at least to the drip line. Watering should be deep and infrequent. Because some soils can’t handle one inch of water all at once with causing run off, you may have to apply water every 3-4 days to get one inch’s worth of water in a week.
Periods of extreme heat, with or without wind, may prevent fruit set on Peppers.
Mature tomato plants suffering from such stress may produce small fruit, hold its fruit on the plant but not enlarge, or drop its flower blossoms.
Diseases and Insects:
While not complete, the following are diseases and insects that are more commonly found this time of year. Contact the Extension office for help with diagnosis and control recommendations.
Insects - Many insects are starting to appear in and around the house. Virginia Tech has
factsheets on many common insects or call our Horticultural Help Line at 703-792-7747 for information on what's "bugging" you and the best and safest way to cure the problem.
Virginia Cooperative Extension
Boxwood blight is a recently introduced fungal disease that causes severe defoliation and decline of susceptible boxwood. It was first identified in Virginia in a nursery location in Carroll County in 2011, but has been found in both landscapes and nurseries in several Virginia counties since then. VCE and the Virginia Department of Agriculture and Consumer Services partnered to form the Virginia Boxwood Blight Task Force (VBBTF) to provide leadership to protect Virginia’s boxwood nursery industry, historical gardens and landscape plantings from boxwood blight. The task force is developing Best Management Practices (BMPs) for boxwood blight for stakeholders potentially affected by the disease (e.g. boxwood producers, retailers, boxwood tip producers, professional landscapers, historic groundskeepers and home growers of boxwood). The task force solicited valuable input on the BMPs from representatives of the various stakeholder groups through meetings and electronic communication.
The BMPs are available for download in PDF format at the VBBTF website.
Anthracnose: Lesions are usually quite large and follow the veins of the leaf. Trees may drop some affected foliage. These diseases normally occur on large trees and do no permanent damage – practice good sanitation by cleaning up fallen leaves. You may choose to apply a preventive fungicide treatments next spring. A certified pesticide applicator and certified arborist can make these treatments for you. Plants susceptible: ash, maple, sycamore and oak trees.
Fireblight is caused by a bacteria. The most typical symptom is branch die back from the tip down typically resembling a shepherd’s crook. Affected branches usually start dying in mid-May or June. Prune out dead branches about a foot below the dead tissue. Sterilize pruning shears between cuts. Plants susceptible: cotoneaster, pyracantha, apples, pears and Bradford pears.
Juniper Tip Blight is characterized by dead branch tips in juniper plantings. Two different fungi cause this blight. Small outbreaks can be pruned out. Fungicides are also an option. The timing of the treatments depends on the causal fungus. Blight caused by Phomopsis is treated in the spring. Blight caused by Kabatina is treated in the fall.
Oak Leaf Blister: The light green to yellow spots will turn dark brown or black later in the season. This disease is primarily cosmetic and requires no action.
Rose Rosette Disease (RRD): A disease believed to be caused by the recently identified Rose Rosette Virus, has been spreading through much of the wild rose population of the Midwestern, Southern, and Eastern United States for years. It has been confirmed in cultivated roses in Virginia and other states.
Environment and Natural Resources
8033 Ashton Ave. Suite 105
Manassas VA 20109
Virginia Cooperative Extension complies with the Americans with Disabilities Act. If you are a person with a disability and require auxiliary aids services or other accommodations for a workshop or meeting please discuss your accommodation needs at least five days prior to the event with Virginia Cooperative Extension 703-792-6289/TDD PC 1-800-828-1120.