Willows are pretty divisive trees — most people either love them or hate them.
It’s easy to understand why they have a bad reputation among some. Most willows have weak wood and produce shallow, invasive root systems, which can damage hardscapes and create landscaping conflicts. But on the flip side, willows can be attractive trees that thrive in the Central Coast region and provide a number of important benefits.
Whether you enjoy your willow tree or are considering replacement, it’s important to understand its basic needs and care requirements. We’ll share some of the most important things to understand about these trees below.
Common Willows on the Central Coast
There are approximately 30 different true willows (genus Salix) native to California, and several nonnative species are commonly planted along the Central Coast. However, many willows are very small shrubs or bushes and never reach tree-like proportions.
So, we’ll outline a few of the native species that typically become proper trees, as well as the most common nonnative ornamentals in our region.
- Red Willow (Salix laevigata): A Central Coast native that’s often found along streams and wetlands, the red willow can reach 30 to 60 feet tall under favorable conditions.
- Pacific Willow (Salix lasiandra): Native to parts of California, including some Central Coast riparian corridors, this species typically grows 25 to 50 feet tall with a more upright form than many willows.
- Goodding’s Black Willow (Salix gooddingii): Native to California but more common inland and in southern regions than along the Central Coast, this large riparian willow typically grows 30 to 60 feet tall.
- Arroyo Willow (Salix lasiolepis): Native to California’s Central Coast, this common riparian species typically grows 15 to 30 feet tall and is well adapted to seasonal water availability.
- Sitka Willow (Salix sitchensis): Native to coastal regions of California, including parts of the Central Coast, the Sitka willow generally grows 10 to 25 feet tall and is well adapted to moist, coastal conditions.
- Hooker’s Willow (Salix hookeriana): Native to the California coast, this shrubby willow typically reaches 6 to 20 feet tall and is well adapted to dunes, wetlands, and coastal scrub.
- Sandbar Willow (Salix exigua): Native to our state but more common along inland waterways than the immediate Central Coast, this colony-forming species typically grows 6 to 15 feet tall and spreads aggressively.
- Weeping Willow (Salix babylonica): Not native to California but widely planted as an ornamental, the weeping willow typically reaches 30 to 50 feet tall and performs best with reliable water.
- Corkscrew Willow (Salix matsudana ‘Tortuosa’): Not native to California and grown as an ornamental cultivar, corkscrew willow typically reaches 20 to 40 feet tall and is valued for its twisted branches.
- White Willow (Salix alba): Native to Europe and western Asia and occasionally planted in California, white willows can grow 50 to 80 feet tall and often develop structural weaknesses with age.
It’s important to note that the desert willow (Chilopsis linearis) is also commonly planted in our region. However, it is not a “true” willow, and it has different needs.
How to Care for Willow Trees
Every individual willow species does have a unique set of requirements, but in general, most willows require roughly similar care. In most cases, you’ll be successful if you follow the five recommendations detailed below.
1. Plant the Right Tree in the Right Place
Proper tree care starts with planting site selection; you have to choose a suitable location to give your tree the best chance at thriving. In the case of willows, that generally means picking a spot that receives full sun, as well as somewhere you can either install an irrigation system or manually water easily.
However, it is also wise to avoid planting locations near hardscapes or high-value landscape features, given the shallow root systems willows produce. And because willows are often weak-wooded, you should also avoid placing them where they may create safety issues in the future.
2. Provide Supplemental Water When Appropriate
It’s always important to provide young and recently transplanted willow trees with significant amounts of supplemental water. And while some willows become tolerant of short-term rain deficits upon reaching maturity, even established specimens will require supplemental water during extended droughts.
Just be sure to water your willow trees deeply but infrequently (perhaps once per week). This helps to limit runoff and encourage deep root development.
3. Apply a Layer of Mulch Over the Roots
When applied correctly, mulch provides a number of benefits for willow trees. It not only helps to protect the roots from mower damage and temperature extremes, but it also helps to retain soil moisture, reduce soil compaction, and contribute organic material to the soil.
Ideally, you’ll want to cover the entire root zone (at least as far as the canopy’s drip line) with a 2- to 4-inch-thick layer of organic mulch. Just be sure to avoid piling mulch up against the trunk, as this can encourage fungal growth, causing the trunk to decay.
4. Fertilize Your Trees Appropriately
Fertilizer is a wonderful tree-care tool, which can help correct any nutritional deficiencies in the soil and promote accelerated growth (though rapid growth isn’t always desirable for these already fast-growing trees). However, you must fertilize your trees appropriately to avoid wasting money or directly harming them.
To do so, you’ll need to start by conducting a soil test to identify the specific deficiencies present. Then, you can select a slow-release fertilizer that’s perfectly matched to your soil.
5. Monitor Your Trees Regularly
Because even the healthiest willow trees can quickly begin to present safety issues or decline, it is important to monitor them regularly for signs of trouble. This means carefully examining all aboveground portions of the tree (including the visible roots), often with the help of a good pair of binoculars.
Minimally, you’ll want to examine your willow trees with the passing of each season, as well as following any significant storm events.
Trimming & Pruning Willow Trees
Regular pruning can be very helpful for willow trees, as it’ll not only keep them vigorous and beautiful but also safe. You’ll typically need professional help to ensure they’re pruned safely (and avoid the injuries that frequently occur during DIY pruning attempts), and you’ll want to do so in the following situations:
- During the first few years of the tree’s life. It’s important to prune trees early, as this will help encourage good form and eliminate problematic branch unions before they become big, dangerous, and expensive problems.
- Anytime you notice damaged, diseased, or dangerous limbs. Even healthy willow tree limbs can fail pretty easily, so it is vitally important that you have any compromised branches pruned immediately.
- Regularly, about once every three to five years. By having a certified arborist prune your tree regularly, your tree will not only look better but also remain safer and healthier.
- Whenever they create site use conflicts or access problems. Sometimes, willow trees may encroach on your roofline or block access to portions of your property, which may necessitate pruning work.
Willow Tree Pests, Pathogens, & Problems
Willow trees typically grow fast and establish themselves quickly, but this makes them vulnerable to a number of insects, diseases, and other problems. A few of the most significant problems they suffer from include:
- Willow Blight Complex: Usually caused by a combination of infections (willow scab and black canker), this disease causes foliar spotting, blackened shoots, and twig dieback. It’s most commonly a problem for dense willow stands during cool, moist springs.
- Melampsora Rust: A fungal problem that causes willow leaves to develop yellow spots or waxy orange pustules on the lower surface of leaves. Melampsora rust requires two host species to complete its complex lifecycle.
- Leaf Spots: There are a variety of different fungi that can cause leaf spot diseases in willows, and it usually isn’t necessary to identify the specific species affecting the tree. Willow will generally recover from leaf spot diseases, but repeated attacks can weaken trees, leaving them vulnerable to other threats.
- Borers: Perhaps the most significant biological threat to willow trees, borers will tunnel below the bark of willow trees, damaging the living cambium layer and leading to the death of twigs and branches. This can not only stress the tree but also make branches more likely to fail.
- Water Stress: While borers may be the most important living threat to willows, simple water stress is far and away the most common problem we see. Given that most willows are wetland species, it isn’t surprising that they can become stressed during extended droughts.
Signs Your Willow Trees Need Help
The best way to keep your property safe and ensure your willow trees thrive is by monitoring them regularly for any signs of trouble. So, inspect your trees regularly and contact an ISA-certified arborist anytime you notice any of the following.
Cracked Limbs
Even pristine willow tree limbs can be at increased risk of failure, so it is especially important to have cracked (or otherwise damaged) limbs evaluated promptly. Timely pruning can help keep the tree safe and prevent failing branches from causing large patches of bark to be stripped from the tree as the branch falls.
Hollows
Because they’re fairly vulnerable to fungi and decay, willows frequently develop large hollows. These hollows provide important habitat for wildlife, and they can even be visually appealing in some cases. However, they also indicate that the tree’s structural integrity may have been compromised.
Mushrooms
Arborists consider the presence of mushrooms to be a “definitive” indicator of decay. Removal may not always be required, but it is important to have willows with any symptoms of fungal activity assessed. Because mushrooms are often short-lived, you’ll want to photograph any that you see, so you can show them to your arborist.
Changes in Lean
Many willows develop a slight lean over many years, and this is usually not cause for concern. However, trees that begin leaning suddenly or exhibit an increasing lean may be at imminent risk of failure. When this happens, you’ll want to have an ISA-certified arborist assess the tree immediately.
Insect Activity
Because their tissues are often relatively rich in sugar, willows tend to attract a lot of insects, which feed on various parts of the tree. Some of these insects will respond to insecticide treatments, but it is important to initiate treatments quickly to achieve good results and give your tree the best chance of a full recovery.
Crown Dieback
The progressive death of branches within a willow’s canopy can be a troubling sign that always deserves attention. There are a variety of pests and diseases that can cause crown dieback, and even environmental issues — particularly soil chemistry or moisture-level problems — can trigger this problem.
Wilting Foliage
Because willows typically require high soil moisture, they may begin to wilt during extended droughts or exceptionally high temperatures. It’s important to correct these issues quickly, as trees can reach something called the “permanent wilting point,” at which time they become impossible to save.
Adney Tree Service: Your Source for Willow Tree Care & Maintenance
Whether you love your willows and need help ensuring they remain healthy and look their best for years, or you’d like to have the willows on your property removed and replaced with something else, Adney Tree Service is ready to help.
Led by an ISA-certified arborist and backed by more than a decade of stellar reviews across Google, Yelp, and Trustindex, we’ve built a reputation as the tree-care partner Central Coast residents and businesses can trust. Contact us today to discuss your tree-care needs or request a free estimate.
Sources and References
- Calflora – “Salix laevigata (Red Willow)”
Provides distribution, taxonomy, and native range information for red willow, supporting its identification and ecological context in California.
https://www.calflora.org/app/taxon?crn=7262 - CalScape – “Salix laevigata (Red Willow)”
Describes habitat preferences, growth characteristics, and ecological value of red willow as a native riparian species in California landscapes.
https://calscape.org/Salix-laevigata-(Red-Willow) - Cornell University – “Willow Diseases”
Outlines common diseases affecting willow species, including cankers, rusts, and leaf pathogens, relevant for risk assessment and management.
https://willow.cals.cornell.edu/research/diseases/ - Oregon State University – “Salix matsudana ‘Tortuosa’”
Details the growth habit, ornamental features, and site requirements of corkscrew willow, including its non-native status and structural tendencies.
https://landscapeplants.oregonstate.edu/plants/salix-matsudana-tortuosa
