Natural Resources

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: 

Master Gardeners The Teaching Garden
​​Publications & Additional Resources Horticulture Classes
Stormwater Management
Landscaping Guide for HOA's Horticulture Speaker Request
New and Emerging Pests BEST Lawns
​​Championship & Historic Tree Registry Pesticide Training Page​
Audubon at Home​ Commercial Landscaping Classes
​Virginia Household Water Quality Program ​Other Regional Classes


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Seasonal Tips

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, give our Extension Horticultural Help Desk a call at 703-792-7747
or email us at

Horticultural Tips 
The best time to apply a spring fertilization is between May 15 and June 15.  Research indicates that a light fertilization of half a pound of nitrogen (.5) per thousand square feet will help prepare your grass for the summer.  If your lawn needs a spring overseeding, the best time to do it is between March 15 and April 15; otherwise you should wait until late August and the month of September.  Remember to keep your lawn mower blades sharp and continue to mow regularly.
Spring is also a good time to take a soil test.  Soil test boxes and instructions can be obtained from the Extension Office at (703) 792-7747 or at local Prince William County Libraries.  Test results will help you determine what your soil needs in order to grow a healthy lawn. 
Some tips for getting the most out of seed include:

• Use fresh seed and varieties that have been proven to do well in our region
• Amend your soil based on soil test results
• Mow a little lower that you normally would just before you reseed to help new seedlings get access to the sun
• Keep the soil moist but not soaked while the seeds germinate
• Avoid heavy traffic on reseeded areas for at least four weeks
Tree leaves are an excellent resource for your lawn and garden. Evergreen needles make good mulch material because take a long time to break down. Deciduous leaves, on the other hand, breakdown much more quickly and are often better suited for composting. While many home owners will gather all their leaves for the compost pile, leaving some on the ground can be beneficial for your turf. With a sharp mower blade and pre-mow removal of sticks, you can use your lawn mower to chop leaves that have fallen on your turf.

If you have additional questions, give our Extension Horticultural Help Desk a call at 703-792-7747 or click here to send an e-mail to us. It’s 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.
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. 
Many insects are starting to appear in and around the house.  Virginia Tech has factsheets on many common insects.  VT Fact Sheets Insect ID or call our Horticultural Help Line for information on what's "bugging" you and the best and safest way to cure the problem.
Boxwood Blight - 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 fore you.

Plants susceptible:  ash, maple, sycamore and oak trees.

Fireblight:  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:  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.

Virginia Cooperative Extension
Environment and Natural Resources
8033 Ashton Ave. Suite 105
Manassas VA 20109
703-792-6285 - e-mail
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