Resistant does not mean immune
No tree is completely free of disease or pests. “Disease-resistant” generally means a species or cultivar is less likely to be seriously affected by particular problems, such as Dutch elm disease or dogwood anthracnose. Resistance can also vary by region, climate and the strains of a pathogen present locally. Treat the lists below as starting points and confirm with a local nursery or extension service.
How to choose a resilient tree
- Match the tree to the site. Stressed trees are more prone to problems. A species suited to your soil, light and climate is already ahead.
- Prefer native or well-adapted species where possible.
- Look for named resistant cultivars when you want a species that has a known issue.
- Buy healthy stock with a good root system and no wounds.
- Diversify. Planting a mix of species limits the damage if a pest hits one type.
Shade and ornamental trees with good records
- Ginkgo (Ginkgo biloba): Long regarded as a tough, low-maintenance urban tree with few serious pest or disease problems. Choose male trees, since females drop messy, foul-smelling seeds.
- Kousa dogwood (Cornus kousa): Generally less affected by dogwood anthracnose than flowering dogwood (Cornus florida).
- White oak (Quercus alba): A long-lived native hardwood, valued for strength and resilience.
- Southern magnolia (Magnolia grandiflora): Few common serious problems in suitable warm climates.
- Persian parrotia (Parrotia persica): An ornamental with fall color and a good reputation for health.
- Paperbark maple (Acer griseum): Peeling cinnamon bark and generally good overall health, though slow growing.
- Lacebark elm (Ulmus parvifolia): Considered more resistant to Dutch elm disease than many other elms, including selected cultivars. Check the cultivar and local conditions.
Evergreens
- Eastern red cedar (Juniperus virginiana): Tough in its native range, though it can host cedar-apple rust, which affects apples and crabapples nearby. Cedar-apple rust is described in orange dots and fungus on trees.
- Thuja ‘Green Giant’: Fast-growing and widely used for screening, with generally few problems, though it can suffer in poorly drained soil. See our guide to trees for waterlogged soil if drainage is a concern.
Resistant cultivars of troubled species
Some familiar trees have a problem that breeders have worked to reduce:
- Elms: Disease-tolerant hybrids and cultivars have been developed for Dutch elm disease.
- Dogwoods: Kousa dogwood and some hybrids resist anthracnose better.
- Crabapples: Many modern cultivars are rated resistant to scab and other leaf diseases. Ask your nursery for ratings.
- Fruit trees: Disease-resistant apple and other fruit cultivars exist. Look for descriptions of specific resistances.
Trees that do not get very big
Smaller yards benefit from compact trees such as kousa dogwood, paperbark maple, parrotia (which can eventually be broad), and selected crabapple cultivars. Always check the mature height and spread of the specific cultivar.
Check whether a tree is invasive
Some highly pest-free trees are so adaptable that they spread into natural areas. Examples sometimes flagged include Norway maple, Callery pear and tree-of-heaven, depending on region. Check your state or local invasive species list before planting. A resilient tree that escapes into woodland can cause problems for years.
Keeping any tree healthy
- Plant at the right depth and give roots room.
- Water deeply during dry spells while young.
- Mulch without piling it against the trunk.
- Avoid wounding the trunk with mowers or trimmers.
- Prune correctly, and at the right time of year for the species.
- Watch for early signs: spotted or wilting leaves, dieback, oozing, or unusual growths.
Trees also need to survive their site; learn more in our guides to wind-resistant trees and trees for hot, dry climates.
If your tree is already sick
Identifying the problem is the first step, because treatments differ for fungal diseases, bacterial diseases, insect pests and environmental stress. Take photos, note symptoms and when they began (our guide to healthy vs unhealthy trees helps you describe them), and contact a certified arborist or your local extension office. Some trees recover with improved care, others with targeted treatment. In some cases, such as certain vascular wilts, a tree may not be saved. Be cautious of any product that promises a universal cure, and avoid heavy pruning or fertilizing before you know the cause.
FAQ
Can a tree survive a fungal infection?
Often yes, particularly if the infection is caught early and the tree’s overall health is good. Outcomes depend on the fungus, how much of the tree is affected and the tree’s vigor.
How do you save a diseased tree?
Start with a proper diagnosis. Common supportive steps include correct watering, mulching, removing dead or infected material and, where appropriate, professional treatment. An arborist can say whether the tree is worth saving or is a safety risk.
What is the most invasive tree?
It varies by region. Tree-of-heaven and Callery pear are frequently cited examples in North America. Local invasive plant lists are the best reference.