Introduction
Most homeowners think about tree watering in spring and summer and stop thinking about it once fall arrives. For deciduous trees that drop their leaves this is largely fine. For evergreens, stopping water in fall is a mistake that shows up in spring as brown, burned, or dead foliage that can take years to recover.
Virginia sits in a climate zone where winters are mild enough that the ground rarely freezes deeply, but cold enough that root activity slows dramatically. Evergreen foliage, however, does not go dormant. Needles and broadleaf evergreen leaves continue to transpire, releasing moisture into the air, throughout the winter. When the soil is too cold for roots to replenish that moisture, the foliage desiccates from the inside out.
This guide explains why winter watering matters for Virginia’s evergreens, which species are most at risk, what products help, and exactly when and how to water through the winter months in Hampton Roads and the surrounding region.
What Is Winter Desiccation (Winterburn)?
Winter desiccation, commonly called winterburn or winter burn, occurs when an evergreen loses more moisture through its foliage than its root system can replace from frozen or near-frozen soil. The result is browning that typically appears first on the foliage facing prevailing winter winds or exposed to the most sun, since both wind and sun accelerate moisture loss.
According to Virginia Cooperative Extension, winterburn is one of the most common causes of evergreen decline in Virginia, particularly in newly planted specimens that have not yet established deep root systems. [Source: ext.vt.edu/tags/evergreens] The damage is often mistaken for disease or pest problems in spring when the brown foliage becomes visible as temperatures warm.
Which Evergreens Are Most at Risk in Virginia?
Arborvitae (Thuja species). Among the most commonly planted and most commonly damaged evergreens in Hampton Roads. Their flat, fan-like foliage has significant surface area for moisture loss. Newly planted arborvitae are particularly vulnerable in their first two winters.
Leyland cypress. Fast-growing and widely planted in Virginia for privacy screens, Leyland cypress is susceptible to winterburn, especially on the windward side. See also our blog on deer and arborvitae for other evergreen threats. [Internal link: Blog #40]
Boxwood. A landscape staple throughout Chesapeake and Virginia Beach. Broadleaf evergreens like boxwood lose moisture through their leaves all winter and benefit significantly from pre-winter watering and anti-desiccant application.
Holly (Ilex species). American holly and its cultivars are native to Virginia and more cold-hardy than many introduced evergreens, but they still benefit from adequate soil moisture heading into winter.
Newly planted pines and spruces. Established loblolly pines handle Virginia winters well, but newly planted pines and spruces in their first one to two winters are at higher risk of desiccation stress.
When to Water Evergreens in Virginia in Winter
Late Fall Deep Watering (October–November)
The most important watering timing for evergreens is a thorough deep watering in late October through November, before the soil temperature drops below 40°F and root activity essentially stops. This pre-winter deep watering fills soil moisture reserves that the tree will draw on through the winter months. Water deeply and slowly at the drip line, targeting soil saturation to 12 to 18 inches depth. A soaker hose run for 45 to 60 minutes around the drip line achieves this effectively.
Winter Thaw Watering (December–February)
Virginia winters include periodic warm spells where temperatures rise above 40°F for several consecutive days. These thaw periods are windows for supplemental evergreen watering. When daytime temperatures are consistently above 40°F for at least two to three days, water newly planted and vulnerable evergreens deeply. Water in the morning so it can percolate before temperatures drop again at night. Do not water when the soil is frozen.
Early Spring Watering (February–March)
As temperatures begin warming in late February and March, evergreen root activity resumes before deciduous trees break dormancy. This is the period when early supplemental watering pays dividends, helping evergreens transition from winter moisture deficit to active spring growth. See our spring watering guide for Virginia for full timing details on this season.
Anti-Desiccant Sprays: Do They Help?
Anti-desiccant sprays, sometimes called anti-transpirant sprays, coat evergreen foliage with a thin waxy film that reduces moisture loss through the leaf surface. They are most useful for newly planted evergreens in their first two winters and for broadleaf evergreens like boxwood and holly in exposed locations.
Wilt-Pruf is the most widely used anti-desiccant product for home landscapes. (wiltpruf.com, also available at Home Depot, Lowe’s, and Amazon: https://amzn.to/4w6Pf1K). Apply in late November or early December when temperatures are above 40°F but before hard freezes arrive. A second application in late January extends protection through the rest of winter.
Anti-desiccants are not a substitute for adequate soil moisture. They reduce moisture loss at the foliage, but if the soil is severely depleted, the tree still suffers. Use them in combination with proper fall watering, not instead of it.
Mulching to Protect Winter Soil Moisture
A 3 to 4 inch layer of mulch over the root zone of evergreens before winter serves two purposes: it moderates soil temperature, slowing the freeze that cuts off root activity, and it reduces surface moisture evaporation from the soil. Apply mulch in November before the first hard freeze. Keep it several inches away from the trunk. Wood chip or shredded bark mulch both work well. This is the single easiest and most impactful thing you can do for evergreens heading into winter.
Distinguishing Winter Desiccation From Disease
Winterburn browning typically appears on foliage facing prevailing winds or in the most sun-exposed locations. It often affects the outer foliage while the interior of the plant remains green. It is most visible in early spring as temperatures warm.
Disease-related browning often starts in the interior of the plant, spreads inward from a specific branch, or appears in a pattern inconsistent with wind exposure. If browning is severe, appears in an unusual pattern, or does not match the winterburn profile, call a tree professional for an assessment before assuming it is weather-related.
Frequently Asked Questions
Should I water my arborvitae in winter in Virginia?
Yes, especially for newly planted arborvitae. Water deeply in late October or November before the ground freezes, and again during any warm spells when soil temperatures are above 40°F. Arborvitae is one of the evergreens most commonly damaged by winter desiccation in Hampton Roads.
How do I know if my evergreen has winterburn or is dying?
Wait until late April before making this determination. Evergreens stressed by winterburn often look worse in early spring before recovery begins. Scratch a small area of bark on a brown branch in April. Green cambium underneath means the branch is alive and may recover. Brown or gray cambium means the branch is dead. If the browning is extensive and the majority of branches show dead cambium, the plant may not recover.
Can I apply anti-desiccant spray in December in Virginia?
Yes, as long as temperatures are above 40°F at application time and will remain above freezing for several hours after application. In Hampton Roads, December typically offers adequate windows for anti-desiccant application. Avoid applying during a freeze or when rain is expected within 24 hours.
Conclusion
Virginia’s mild winters give evergreens an advantage over those in colder climates, but the same mildness means the ground stays accessible for watering when northern gardeners have no option. Use that advantage. A thorough late fall deep watering, a layer of mulch, and an anti-desiccant application on newly planted or vulnerable evergreens is a one-afternoon investment that prevents months of damage.
If your evergreens came out of winter looking stressed or are showing significant browning, call 757 Tree Solutions for an assessment. We serve Chesapeake, Virginia Beach, Suffolk, and Hampton Roads and can help determine whether your trees are experiencing weather-related stress or something that needs more active intervention.
