Description & Overview

Black Willow is a fast-growing Wisconsin native tree found throughout the state but concentrated in the south, southwest, and south-central counties. The average life span is 65 years, which is still a good amount of time, but they can live up to 100 years of age in ideal conditions. A smaller scale tree, typically reaching heights of 30-40′ although in ideal conditions it has been seen to grow up to 65′ or more. A multi-stemmed tree, Black Willow usually forms a clump and can appear somewhat shrubby in form. Its leaves are green and narrow and flexible twigs are a light-red shade. The bark is dark grayish brown, nearly black, forming deep fissures as it matures.

Core Characteristics

Category: Tree

Wisconsin Native: Yes

USDA Hardiness Zone: to zone 3

Mature Height: 10-65 feet

Mature Spread: 30-40 feet

Growth Rate: Very Fast

Growth Form: Multi-trunked, shrubby tree

Light Requirements: Full Sun

Site Requirements: Wet to moist soils preferred, adaptable once established.

Flower: Yellow-green catkins, dioecious

Bloom Period: April – May

Foliage: Green, narrow, and smooth on both sides.

Fall Color: Yellow

Urban Approved: No

Fruit Notes: Cottony seeds are dispersed by wind and water.

Suggested Uses

Willows in general love water and Black Willow is no exception. Plant along a waterway to help prevent soil erosion and to soak up excess water. Soil should never be allowed to dry out for this tree to thrive. They are wonderful planted along rivers, streams, or ditches as their shallow root systems are great for binding soil that would be otherwise washed away along waterways. A definite full sun lover, plant in an area that receives at least 8+ hours of sunlight as they are intolerant of shade.

Black Willow is dioecious meaning that its male and female flowers are on separate trees. Flowers are tiny, up to two inches in length, and yellow-green catkins aren’t particularly showy. This tree is most noted for its medium to dark green foliage that provides dappled shade.

Black Willow should not be planted as a street tree or near houses or structures as they are weak-wooded and can break in high winds or heavy ice. Additionally, its shallow, spreading roots may seek out sewer or water pipes. That’s not to say Black Willow isn’t useful, just not when planted around buildings, cars, decks, or anything you don’t want to be damaged.

Black Willow is a fast-growing Wisconsin native tree found throughout the state but concentrated in the south, southwest, and south-central counties. …

Wildlife Value

Speaking of being a useful tree, Black Willow provides many benefits to wildlife and pollinators, and on a scale of 1 to 10, Black Willow ranks high. They are a larval host plant for several butterflies including Acadian Hairstreaks (Satyrium acadica), Morning Cloaks (Nymphalis antiopa), Compton Tortoiseshells (Nymphalis vaualbum), Bog Fritillary (Boloria eunomia), Eastern Tiger Swallowtails (Papilio glaucus), Viceroys (Limenitis archippus), American Ladies (Vanessa virginiensis), and Red-spotted Purples (Limenitis arthemis).

Moths are drawn to Black Willow, well, like a moth to a flame. Palmerworm Moths (Dichomeris ligulella), Twin-spotted Sphinxes (Smerinthus jamaicensis), Tawny Pug Moths (Eupithecia ravocostaliata), Columbia Silkmoths (Hyalophora columbia), Clemen’s Sphinxes (Sphinx luscitiosa), Darling Underwings (Catocala cara), Tufted Apple-Bug Moths (Platynota idaeusalis), Dreamy Duskywings (Erynnis icelus), and Clouded Sulphurs (Colias philodice).

Willows are among the first plants to provide nectar and pollen to honey bees after winter. Our pollinator friends who often visit Black Willow include specialist short-tongued bees in the Mining family (Andrena spp.): Sandbar Willow Fairy bees (Perdita maculigera), Colorful Willow Miner bees (Andrena andrenoides), Wellesley Miner bees (Andrena wellesleyana), and Small Willow Miner bees (Andrena salictaria). Other short-tongued bees include a range of Furrow, Cellophane, Plasterer, and Sweat bees.

Long-tongued bee visitors include Brown-belted bumblebees (Bombus griseocallis), American bumblebees (Bombus pensylvanica), Honeybees (Apis mellifera), Spurred ceratinas (Ceratina calcarata), Doubled ceratinas (Ceratina dupla dupla), and a variety of Nomada bees.

Black Willow also draws many species of beneficial flies, wasps, ants, and beetles.

Many forms of wildlife will graze on Black Willow including livestock, elk, beaver, goats, horses, small rodents, and deer, as well as Snapping and Wood turtles who will feed on fallen leaves or catkins.

Songbirds and waterfowl will browse buds in the early season including Prothonotary warblers, Warbling Vireos, Red-winged Blackbirds, herons, Willow Flycatchers, Tree Swallows, and Downy and Red-bellied woodpeckers will use young trees, larger trees, or dead snags as nesting sites.

The shallow roots of the Black Willow make excellent habitats for aquatic species that dwell on the water’s edges seeking shade.

Maintenance Tips

Black Willow can be considered high maintenance if planted somewhere where they shouldn’t be – as a street tree, around buildings, houses, decks, cars, etc. – and can be messy. Its fast growth rate means that its branches are brittle, making it susceptible to breakage, ice, and wind damage. Yard clean up after a windy day may need to be worked into your schedule. Or plant it somewhere where the occasional fallen branch isn’t an issue – away from streets, buildings, houses, decks, cars, etc. – you get the drift.

Any pruning should be done in the late winter or early spring.

Pests/Problems

Black Walnut Tolerant: Yes
Deer Resistant: No
Rabbit Resistant: No

As mentioned previously, many animals like to eat this plant, making it a great choice to expand your wildlife garden. If that is undesired, perhaps opt for a different tree altogether.

As a native tree, it is susceptible to cottonwood leaf beetle, willow sawfly, stem borers, twig borers, Willow blight, and cankers. That said, keeping the soil wet will reduce stress and potential insect infestation.

Leaf Lore

The genus Salix comes from Latin and was already used to refer to willows by the Romans. Not much information exists on how the name came to be; however, there are theories that it actually comes from the Celts. Referring to the preferred habitat of willows, the Celtic language “Sal” means “near” and “lis” means “water.” The specific epithet nigra means “black.” The common name ‘willow’ is a derivation of the Old English word wilwe.

In terms of uses, Black Willow was used widely by many, in interesting ways. The pain reliever salicylic acid was a compound isolated from willows back in the 1840s and was used to reduce fevers and minimize pain. The word “salicylic” is rooted in the genus Salix.

Indigenous peoples used the roots to make a yellow dye for Porcupine quills. NativeTech: Natural Dyes for Porcupine Quills. The Cherokee made a tonic from the bark for hoarseness or as an infusion to reduce fever, while the Micmac used Black Willow as a poultice for sprains and bruises. The Iroquois made decoctions for dyspepsia, coughs, and mouth or throat abscesses.

Fibers from the flexible twigs were once used for coiling basketry. Today, Black Willow wood, with its softness, is used for crates, pallets, wooden utensils, and the core of furniture.

If you’re curious about Salix in general, there are some interesting uses that date back to the fifth century BC-everything from medicines to love potions.

Companion Plants

Plant Black Willow along with trees that enjoy similar sites such as Eastern Cottonwood (Populus deltoides), Black Spruce (Picea mariana), Buttonbush (Cephalanthus occidentalis), River Birch (Betula nigra), American Sycamore (Platanus occidentalis), American Elm (Ulmus americana), Tamarack (Larix laricina), Quaking Aspen (Populus tremuloides), and Yellow Birch (Betula alleghaniensis).

Perennials to combine with Black Willow include Spotted Joe-Pye Weed (Eutrochium maculatum), Wild Hyacinth (Camassia scilloides), Shreve’s Iris (Iris viriginica var. shrevei), Obedient Plant (Physostegia virginiana), Swamp Milkweed (Asclepias incarnata), Meadow Anemone (Anemone canadensis), Glade Mallow (Napaea dioica), Cinnamon Fern (Osmunda cinnamomea), and White Turtlehead (Chelone glabra).

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Written by Beth DeLain