Eastern Red Cedar (Juniperus virginiana) is a distinctive and resilient native tree across eastern North America. This widely distributed conifer plays a significant ecological role, adapting to various landscapes from open fields to woodland edges.
Understanding Eastern Red Cedar
Eastern Red Cedar (Juniperus virginiana) is an evergreen tree, typically conical or pyramidal, though mature forms can become more rounded. It typically reaches 30 to 60 feet tall and spreads 8 to 20 feet wide, requiring full sun (at least six hours daily) for optimal growth.
The tree tolerates a wide range of soil conditions, from dry and rocky to slightly alkaline or acidic, with a pH range of 4.7 to 7.8. Once established, Eastern Red Cedar is remarkably drought-tolerant due to its extensive fibrous root system. It provides shelter and food, particularly its blue, berry-like cones, for numerous bird species, including the Cedar Waxwing, and various small mammals. Its dense foliage also offers year-round cover and contributes to erosion control.
The Challenge of Cedar-Apple Rust
A notable challenge associated with Eastern Red Cedar is its role as a host for Cedar-Apple Rust, caused by the fungal pathogen Gymnosporangium juniperi-virginianae. This disease is unusual because it requires two different plant hosts to complete its life cycle: Eastern Red Cedar or other junipers, and plants from the Rosaceae family, primarily apples and crabapples.
The fungus overwinters on the Eastern Red Cedar in the form of reddish-brown galls, which can range from a quarter-inch to over two inches in diameter. In spring, during warm, rainy periods, these galls produce distinctive orange, gelatinous protrusions (telial horns) that release wind-borne spores. These spores can travel for miles to infect susceptible apple, crabapple, or hawthorn trees.
On the Rosaceae hosts, symptoms manifest as bright yellow-orange spots on leaves, which may enlarge and develop concentric rings. Infected fruit can become disfigured, and severe infections can lead to premature leaf drop, reducing fruit quality and tree vigor. While the rust rarely causes severe damage to the Eastern Red Cedar itself, its impact on susceptible fruit trees can be significant, weakening them over time.
Ideal Companion Plants for Eastern Red Cedar
Selecting companion plants for Eastern Red Cedar involves choosing species that share similar growing preferences for full sun and well-drained soil, while also being unaffected by or resistant to Cedar-Apple Rust. Native shrubs are excellent choices, adapted to comparable conditions. Inkberry (Ilex glabra) provides evergreen foliage and berries without being a rust host. American Beautyberry (Callicarpa americana) also thrives alongside cedars, offering vibrant fruit displays.
Perennials that tolerate dry, sunny conditions can form attractive underplantings. Good selections include Liatris species (known for tall, purple flower spikes), various coneflowers (Echinacea spp.) that attract pollinators, and tall garden phlox (Phlox paniculata).
Groundcovers can help suppress weeds and retain soil moisture. Creeping sedum, such as ‘John Creech’ (Sedum spurium ‘John Creech’), is a hardy, drought-tolerant option for a low-maintenance carpet. Little Bluestem (Schizachyrium scoparium), a native grass, offers textural contrast and thrives in similar dry, sunny conditions.
White Oak (Quercus alba) can also be a compatible tree companion, as it is not a host for cedar-apple rust and shares the cedar’s preference for well-drained sites.
Plants to Avoid Near Eastern Red Cedar
To prevent the spread of Cedar-Apple Rust, certain plants from the Rosaceae family should be avoided or planted at a considerable distance from Eastern Red Cedar. The most commonly affected are apple (Malus domestica) and crabapple (Malus spp.) trees, which act as alternate hosts. Infection leads to leaf spots, fruit deformities, and overall weakening.
Other susceptible Rosaceae family members include:
Hawthorn (Crataegus spp.)
Quince (Cydonia oblonga)
Serviceberry (Amelanchier spp.)
Mountain-ash (Sorbus spp.)
Flowering quince (Chaenomeles spp.)
Cotoneaster (Cotoneaster spp.)
Chokeberry (Aronia spp.)
Photinia (Photinia spp.)
While some apple cultivars show resistance, such as ‘Redfree’, ‘Liberty’, ‘William’s Pride’, ‘Freedom’, ‘Winesap’, and ‘Paula Red’, it is generally advisable to maintain a distance of several hundred feet between Eastern Red Cedars and susceptible fruit trees to minimize disease transmission.
Essential Planting Considerations
When planting near Eastern Red Cedar, proper spacing is important to accommodate its mature size and ensure air circulation. While a mature Eastern Red Cedar can reach 8 to 20 feet wide, a common recommendation for windbreaks is to space seedlings 6 to 10 feet apart, or 12 to 24 feet apart for individual specimens. Adequate spacing allows companion plants to establish without being overshadowed or competing excessively for resources.
Eastern Red Cedar prefers full sun and tolerates a wide range of soil types, from dry and rocky to loamy, though well-drained conditions are consistently preferred. Companion plants should share similar light and soil requirements for success.
Initial watering is crucial for newly planted companions, requiring consistent moisture for the first one to two growing seasons until they are established. After establishment, both the cedar and its companions will largely benefit from their shared drought tolerance.