vallis Plant Materials Center
Oregon Native Willow Varieties for the Pacific Northwest Native Preface Contents Willow
Varieties for The use of native plants for restoration and Introduction...... 1 re vegetation is receiving renewed popular the Pacific inlereslnatioll widc. Thisdocumcnt [mponance of wi ll ows ...... 1 describes six willow varieties that are suitable for such purposes, if prudently 'Clatsop' hooker willow ...... 2 Northwest and intelligently applied. They are: - 'Clalsop' hooker willow 'Multnomah' Columbia River willow .. .4 -' Multnomah' Columbia River willow . 'Nehalem' Pacific willow 'Nehalem' Pacific willow ...... 6 Dale C. Darris -'Placer' erect willow Conservation ag ronomist . ' Plumas' si tka willow 'Placer' erect willow ...... 8 U.S. Department -' Rogue' arroyo willow of Agriculture These wi llows were developed and are 'Plumas' sitka willow ...... 10 Soil Conservation Service promoted in response to the need for Corvallis Plant Materials Center locally adapted plant materials that can 'Rogue' arroyo willow ...... 12 Corvall is, Oregon help stabilize eroding streambanks. improve water quality. and enhance or Table-Adaptation and use of willows restore degraded wi ldlilfe habitat in the in the Paci fi c Northwest.... 14 Pacific Nonhwesl. Scott M. Lambert Propagation and establishment 15 Plant Materials Specialist Although the authors have described each U.S. Department wi llow species "natural range" in general Availability .... 15 of Agriculture terms. the reader is encouraged to use Soil Conservation Service official publications on local nora and Related references 15 Spokane, Washington other appropriate botanical references if more specific information on biogeogra- ph y is desired. More attention is given instead to the concept of "area of adapta- ti on" that. as used herein. encompasses a region of similar climate. soils. and topography within which a variety or strain is known or anticipated to do well. Although all th e willows in this publica- ti on are considered either native to all or at least a pan of western Washington. western Oregon. or nonhwestern Califor- nia. "area of adaptation" for some may not be wholly contained within the known distribution of wild populations. For some varieties. the area of adaptation is wider and for others. it is narrower than the species "native" range. Ultimately. the end users of plants must decide whether or not these willow varieties. or any other plants. meet the panicular ecological. physical. aesthetic. and legal requirements of a project.
Original sketches of the willows appearing in this publicaton were created by Gail Lovell. Beavenon. Oregon. All programs and services of the SoH Conservation Service are offered on a nondiscriminatory basis without regard to r(lce, color, religion, sex, age, marital status, handicap, or national origin.
June 1993 Introduction
The U.S. Dcpanmcn\ of Agriculture. Importance of willows Although short-li ved and not pest free, Soil Conservation Service, Plam Riparian wi lluws Me: valuable: for willows are easy to establish, fast Materials Cenler at Corvall is, Oregon. erosion control. Large shrub types that growing. gener
Hooker or coast willow is a medium Description 10 large shrub ":!live (0 (he coastal fog C1UlSOP hooker willow (SCIIi.l bell of northwestern California. Oregon. hookeri(II/{l Barr.ltl ex Hook.) will grow Washington. and southwestern British 10 a height of 1010 26 fect (3 - 8 Ill ) Columbia as well as the Yakullll Bay area depending on the sile. [ts overall of Alaska. II most commonly occurs on appearance is typical of the species. dcnmion plains or stabilized dunes. ncar Mulurc shrubs grown well spuced and in lagoons. :md along slreums within 5 mi les full sun afC dense. multistemmed. and of the coas\. upright to broadly branching in form. 'Clatsop' is a cultivar of hooker The species can be distinguished in pan willow well suiled to sircambank by ils SIOut hairy Iwigs and oblong stabilization and the revegetation of shaped 1e,l\'CS Ihal afC thid:.. woolly coastal marshes or other moist. sandy beneath. and "leathery" 10 the louch. The areas. It may also be used for wildlife broad leaves have margins Ihal are h3bital improvement. nmural area smooth to somewhat wavy. They are landscaping. windbreaks and screens in alternate and deciduous, falling by mid to moist environments. Clatsop was late NO\'ember. Young tw igs are green. cooperatively released in 1988. and the bark of older limbs is dark gray. '''e plant collection that led 10 the release of C[atSOp was made in 1978 by the Soil Conservation Service. The original stand was found in Clalsop County. Oregon, 1·looker willow. like lllOSI willows. bears male and female flowers on separate plants. Clatloop. however. is a female clone and. as such. bears only pislillate (female) catkins in March or April. They are upright. appear before the foliage. and arc retained for several weeks.
2 Performance Adaptation Uses Clatsop hooker willow (9O().l737, PI- Clatsop hooker willow is tolerant of Clatsop hooker willow is 508554) was evaluated in:m mOSl soil textural types and dnlinage recommended for stabilizing the banks of observation:ll row nurscry against 105 classes where moisture is nOllimiling. low velociry streams. improving wildlife clones or :lcccssions comprisi ng atlcast 8 The species. however. prefers moist. habitat. and resroring nalivc plant native species. As the best of four clones sand y. gravelly. or mucky sites at communities along lakes. marshes. and of hooker willow te sted, il was chosen for elevations below 1.500 feet (460 m). It is older dunes near the coast. Deer. moose, its allractive foliage. density. Stout best s uited to streantbanks. moiSI coastal and rabbits browse the sterns; carkins are bmnching. and fewer observ;]ble disease I11c
_ Known adaptation
D Probable adaptation * Origin 01 'CtalSO!)'
3 'Multnomah' Columbia River willow
Columbia River willow is a suckering Description shrub or small tree native only to the Multnomah Columbia River wi llow shores of the lower Columbia River and (S(l/ixjluI'iatilis NUll.) will grow to a related tributaries in western Oregon and height of 1010 20 fect (3 - 6 m), Washington. This once threatened depending on the sile. Its overall species has one of the smallest natuml appearance is typical of the species. distribUlions of all Nonh American Usuall y multistemmed and compact wi th willows. upright. slender branches. this species is 'Multnomah' is a culti var of nOied for its spreading or suckering habit. Columbia Ri ver willow well su iled [0 The leaves are allemme and deciduous. streambanK, shoreline. sandbar. and falling by late November. They are dredge spoil stabi1i:r.ation in the Pacific relmively long and narrow with many Nonhwest. [t may also be used for scanered teeth along the margin s. The wildlife habilal improvement. young twigs are brown or green; the bark windbreaks. o r natural area landscaping of older limbs becomes grayish-brown in moist environments. and scaly wit h age. Both the leaves and twigs are sparsely 10 moderatcly hairy. The plant collection th31 Icd to th e release of Mullnomah was made in 1980 by the Soil Conservation Service. The ori ginal stand was found along the banks of the Sandy Ri ver in Multnomah County. Oregon. Columbia River willow. like most willows. bears male and female flowers on separate plants. Multnomah. however. is a male clone and therefore bears only staminate (male) catkins in May or earl y J une. They appear well after the tree has leafed out in spring. much latcr than most Northwest willows.
4 Performance Adaptation Uses Multnomah Columbiu Rin'r willow Multnomah ColumbiQ River willow is As (In erosion comrol ptOlO! . (9019-UJ9. PI -508553) was the best of6 tolerant of most soil lexlural types and Muhnomah Columbia Ri ver willow is ~urvi\ing clones of Columbia Ri\'cr drainage classes where moisture is nO( particularly well suited to stabilizing \\ illow from an original assembly of 24. limiting, However. it prefers moist sand. sandbars and dredge spoil s because of its It was chosen for its survi\'al. male sex. gravel, or silt. It is best suited to sandbars ability 10 sucker and colonize open. sandy ability to spread from underground stems. Ilnd the banks of streOl mS. 100kes. Olnd areas. II can also be u~ for well:mrl and aHractive foliage. and compact form. In ponds at elevations below 1.500 feet (460 riparian area restoration. screens, wind- field tests. Muhnomah dcmonSirated m). On upland sitcs, the average annual breaks. bank stabilization along low rapid initial growth during the first few precipitntion should exceed 40 inches velocity streams, reservoir shoreline years after establishment. It had an (101.6 cm). This is a pioneer species. It plantings. an d natural area landscaping, o\'crJII survival rate of 63 percent in cannotto!erate shade nor excessive plant This variety enhances wildlife habitat. moist environmems under low mainte- competition. Deer and rabbits browse the stems and nance conditions, Known areaS of adaptation include foliage: catkins and buds are food for the lower Columbia Ri ver drainage as small game and songbirds. Shade from well as valleys and riparian areas west of mature willow trees reduces waler the Cascade Mountain ridge in Oregon temperatures and impro\'es fisheries. and Washington. Potential areas of Multnomah may also be used for certain adaptation. however. may extend to those slream and slope protection measures regions of similar climate and soils within sueh as wauling. brush matt ing. and USDA plant hardiness zones 7a to 9b. branch packin g: it may be used alone or with traditional mechanicaltrealments such as rock riprap.
_ Known .daptation
D Probable.a.ptation * Origin oI'Multnomah'
5 'Nehalem' Pacific willow
Pacific willow is a large shrub or toahcightof6to]Ofeet(I.8 - 9.1 m) smull tree native IQ westem Nonh depending on the site. Its app<:lLfance i3 America from California to Alaska, typical of the species and includes the including the Rocky Mountain Slaies. presence of a whitish bloom on the Albcna. and British Columbia. It most underside of the leaves. The foliage is commonly occurs along lakeshores. in relatively long-pointed, finely toothed stream corridors, and on moist sites along the margins, :md simi lar in shape to throughout its natural range. EcOIYpeS of the leaves of a peach tree. Also indicative this species appear more fiood tolerant of the species are tiny glands or protrusions than other native willows. at the base of the leaf blade or tip of the 'Nehalem', a cultivar of Pacific leaf stalk. Alternate and deciduous. the willow. is suited 10 streambank leaves fall by late November. stabilizing if it is planted along the Easily recognizable are the shiny. shorelines of Jakes an d manmade orange or distinctly yellow twigs of reservoirs. [\ may also be useful for Nehalem. Both the leaves :md young stems wildlife habitat impro\'cmcrn, natural are smooth and lack hairs. The bark of the area landscaping, or screens in moist limbs and trunk will become dark gray or environments. Nehalem was brown in color and fissured with agc. cooperatively released in Mature trees grown in a wcll spaced 1988. environment with full sun are usually multistcmmed with a rounded crown. Description The plant collection thm led to the Nehalem Pacific release of Nehalcm was made in 1978 by willow ISalix the Soil Conservation Service. The l(lsial!dra Bcnth. or original stand was found ncar the Nehalem S. /licida Muhl. River in northweslCm Oregon. Pacific ssp. {as;wu/ra willow. like most willows. bears male and (Bcnth.) E. female flowers on separate pl,lnts. Murr.] will grow Nehalem. however. is a male clone and as
6 such. bears only staminate (male) catkins Adaptation Uses in laic April or May. They appear after Pacific willow is lolerum of most soil Nchalem Pacific willow can be used the foliage expands in the spring. lexwral lYJX:s and dminage classes where (or stabilizing the banks of low velocity moisture is not limiting. The species. ~treams. restoring riparian areas. and Performance however. prefers moist. well drained improvi ng shoreline and aquatic habitat Nehalem Pacific willow (9()()..ISI4. sandy loams to gra velly or rich, rocky for fish an d wildlife. As a male clone. it PI-508555) was evalumed in an observa- soils. [I is nat lJ rally suited (0 riparian will not spread by seed but will rcsprout tional row nursery agaiosl 105 _ Known adaptation Probable adaptation * Origin of 'Nehalem' 7 'Placer' erect willow Erect willow is:I medium sized shrub Description nali\"c to California and other parts of the PIIlcCr crect willow will grow 10 a weSlern United Slales. [\ is most com- height of 8 to 18 fecI (2.4 - 5.5 Ill) monly found along watercourses and in depending on the site. The typical moist mc,ldows, 'Placer' is a variety of mature shrub is open at the base, upright crect willow released as Sfllix figlilijo/ill to broadly branching, and muhistemmed (Ball) ex Schneider. The species has with a rounded crown. The leaves arc been renamed S. eriOCf'{lJI(IllI Michx. ssp. relatively long. narrow. light green above liglllijolia (Ball) Argus. and whitish below with small stattered Placer is well suiled \0 stream bank teeth along the margins. Ahhough the stabilizmion. wet siles and low mainte- young twigs are yellowish grecn. the bark nunce plantings where weed competition of older limbs become dark gray. Both may be too severe for Olher willows. It the foliage and twigs generally lack may :llso be used for wildlife habitat pubescence. Ahem I 8 Performance Adaptation Uses Placer (9004765. PI-508556) was Placer erect willow is tolerant of soils Placer erect willow is recommended evaluated in an observational row nursery that vary from moist sand to wet clay is for stabilizing the banks of low velocity against 105 accessions or clones compris- all drainage classes from well drained to streams. renovating riparian area~. and ing at least 8 native species. It was the poorly dmined. It is best suited to improving shoreline and aquatic habitat only clone of erect willow tested. riparian areas. moist meadows. and for fish and wildlife. As a male clone. it Although short-lived. Placer was chosen streambanks at elevations below 1.500 will not spread by seed but will resprout for its high basal stem density. male sex. feet (456 m). Area of adaptation includes readily from the base if broken or attractive foliage. shrub form. and good valleys and stream corridors west of the damaged. Deer and rabbits bruwse the oUiplanting survival. Vigorous shoots Cascade Mountain ridge in Oregon and stems; catkins and bud~ lire food for branch quickly and more readily thll1l WaShington. as well as northwestem small game lmd songbirds. The shade other willows. As with many willows. California. the Sierra Nevada Mountains. created by willows along a ~tream will this variety is susceptible!O different and adjacent foothills. On upland sites. reduce water temperatures and improve pests of which willow canker may be the the average annual precipitation should conditions for many fish. most serious. exceed 35 inches (88.9 em). Potential Placer may also be used for ccnain In 33 field plantings along streams. areas of adaptation may extend to other stream and slope protection measures watercourses. and on similar moist. low parts of the species native range or such as wauling. brush matting. and Illaintenanee sites in westem Oregon and regions of similar climate and soils branch packing; it may be used alone or Washington. the survival rate averaged within USDA pl:lI1t hardiness zones 7b !O with traditional mechanicaltreatmellll> 55 percent. Stands varied from I to 5 9b. l>lIch as rock riprap. Other potential uses years old. Where beller si te selection and include natural an=a landscaping. screens. planting methods were used. the rate and windbreak~ on moist sites. This exceeded 85 percent. Compared to seven variety is more tolerant of grassy weed other willows including 'Bankers' dwarf competition in luw maintenance settings willow (Salix x ,·o/elli). Placer than other native and non-native willows. demonstrated the greatest ability to The narrow leaves lind yellowish-green compete with grasses at an early age. twigs add ornamental value. -* Origin of 'Ptace~ 9 'Plumas' sitka willow Sitka willow is a medium to large Description shrub native to western North America Plumas si tka WI llow (SlIlix site/llmsis from California 10 the panhandle of Sanson ex Bong.) will grow 10 a height of Alaska. It s natural range also CXlc nd~ 10 101023 feCI (3 - 7 Ill) depending on the parts orlhe inhlnd Northwest. Idaho. site. Its appearance is typical of the Montana. and British Columbia. This specie~. Mature shrubs that are well species commonly occurs along streams spaced and grown m full sun are and beaches as well as the borders of multistcmmcd. open. and prcdominatcly meadows and forest clearings. upright in form. The lcaves arc smooth 'Plum3s' is a culli":lf of erect willow or slightly wavy along thc margins. two well suiled 10 strcambank stabilization. to four times as long as they are wide. wildlife habitat improvement, and the dull green abovc. and covcred with rCSIOrJlion of riparian areas. It may also dcnsc. silvery hairs bencath. Thcyare be used for windbreaks. natural area alternatc and dcciduous. falling by mid- landscaping. borders. or screens in moisl to late Novcmber. Although young twigs environments. This variety was coopera- ore colored red. brown. or grecn und tively released ill 1988. slightly hairy. the bark of oldcr limbs is gray and smooth. Thc plant collection thatlcd 10 the rclease of Plumas was made in 1978 by the Soil Conservation Service. The origin is the Plumas region of California ncar Susanvillc. Sitka willow. like other willows. bears male and female flowers on separate plants. Plumas. howevcr. is a male clone and as such bears only staminate (male) catkins in March or April. They appear about the same time as Ihe foliage. 10 Performance Adaptation Uses rluma ~ ~ilka willow (9{)()4 795. 1'1- Sitka willow is tolerant of most soil Plunm~ b recommended for 508558) was cvaluated in an observa- textural lypeS and drainage classes whcre stabilizing thc b:l11ks of low ve10cilY tional row nUl"1>cry :lg:linq 105 :lecessions moisture is nOilimiting. Thc species. streams. improving wildlife habitat, and or cloncs comprbing:ll Ica~t 8 nativc howcvcr. prcfers moist. sandy or mucky renovating riparian arC:ls. Deer. elk. spt.'Cies. A~ I of 22 sources of ~itka sites. II naturJll y does well along moose. and rabbits browse the stems: Ihe ",illow tested. it wu~ chcn;cn for it~ higher riparian areas. freshwatcr beaches. the catkins are food for small game and basal stcm dcnsity. rapid initial growth banks of rivers. and the edge of forest songbirds. The shade created by willows rate. and male sex. Vigorous shoots clearings where sunlight is abundant. along a stream will reduce water branch less frecly than other willows. Known areas of adaptation for temperatures and enh:lnce conditions for lending 10 an upright and open appeM- Plumas include the valleys of western fish. Plumas is a male clone and cannol ance when young. A~ with most willows. Orcgon and Washington. from the spread by seed. When d:Ull(lgcd or Plumas can host cenain insects and Cascilde Mountains to the coast. as well pruned, however. plumas will readily diseases. During the evaluation pe riod. as low to mid-c1cvation (4.00) ft. (1.216 m» resprout from the base. Long. howcvcr. none were considered a limitin g silcs in the Sierra Nevada Mountains and unbranched shoots develop which are factor for the intended usc. northwestern California. On upland sites. excellent for making cUllings. In 42 field plamings along streams. the avcrage annual precipilalion should Along with traditional pl:lnting watercourses. and on similar moist. low exceed 35 inches (88.9 cm). Potential methoos. Plumas can be used forecrtain maintenance sites in western Oregon and areas of (ldaptalion may extend into othcr strcam and slope protection measures Washington. the survival rate averaged parts of the species natural rangc or such as wattling. brush mailing. and 51 percent. Stands varied in agc from regions of similar climate (lnd soils branch packing. alone or in combination I \05 years. In one study. initial growth within USDA plant hardiness zones 6a 10 with traditional mechanicallrealments ratcs wcre the highcst of se\'cn select 9b. such as rock riprap. This v:lricty has willow clones. Where proper site been successfully employed for natural selection and planting methods were arca landsc(lping. windbreaks. screens. used. survival exceeded 85 percent. :lnd borders on moist soils. The ne: -* Origin 01 'Plumas' 11 'Rogue' arroyo willow Arroyo willow is a large shrub or trcc smooth gray bark becomes fissured into (]Ial UCWI ~ Ilillurally fWIIl Baja, Califur- broad ridge:;. nia [0 Washington and caSlto New The foliage is broadly lance shaped. Mexico. Idaho. and Utah. Typical widest beyond the middle. smooth or habitats include moist soils along streams occasionally toothed along the margins. as well as gullies and gulches (arroyos) in dark green above. and whitish below. valleys and foothills. Thi s variety is composed of two clones 'Rogue' is a cuili var of :moyo willow which differ primarily in stem color and suitable for strcambank stabilization and degree of pubescence. One has darker improvement of freshwater fi sheries. It is reddish-brown twigs and more pubes- ulso useful for windbreaks. naturalized cence on the stems and underside of the landscaping, and native screens or shade. leaves than the other. In both cases. the Rogue was cooperatively released in leaves are altemate and deciduous. '990. falling by [ate November. The plant collection that led to the Description release of Rogue arroyo willow was Rogue arroyo willow (Sali.t 11Is;o/epis made in 1978 by the Soil Conservation !lenth.) is a IMgC. multi-stemmed. Service. Vegetative material originated occasionally sing[c-trunkcd spccimcnlhm from a stand growing on the north bank grow.'> to a height of 15 [035 feCI (4.6 - of the Rogue Ri ver in Curry County. 10.6 m). The fonn is upright with a Oregon. Arroyo willow. like most bro..1d. irregular or rounded. spreading willows. bears male and female nowers crown. In the open. this plant on separate plants. Rogue. however. is a will grow about as wide as it male variely and as such. bears only docs tall. With age. the thin. staminate (male) catkins ill March. The catkins appear before the leaveS. 12 Performance Adaptation Uses Rogue arroyo willow (9O _ Known adaptation _ Probable adaptation * Origin of 'Rogue' 13 Tablc.- Ad(ll'lali(H1 t/lld USI" o/willows ill thl" Pacific Northl'·l"sl. Ullitl"tl Sit/US 0/ AII1t!rictJ Key. ' _ ~ (01" good): i _proW.bIy ~ (01" ,.... ,:0 ~ poCenballimiara';';'" (01" pooI"); ? • adaprion 01" use unI ~ lot dIIf."" or~ . CaI 'l/nIque or speaaI altributM. RIMr Ie> Ie'" lor ""'"' details. NcU! that ...... a.I" 10 rNny di$eaSM and inMct p** and a", nallnly shoIt~ . Only ..... disea$e ~ l'r"IOII ~ ObserVed ... 1isIed. AIlhougtIIhoose donn I xpresWog \he gr_ level and numbIr 0/ disease in~ were a.ooidId in \he seIIcIoon p 14 Propagation and approved herbicide. This hould only be dogwood, Sitka alder, and vine maple for establishment done according to label in tructions and floral diversity. Such stand not only in areas where the contamination of create better habitat but may be Ie s Rogue, Plumas, Placer, Clatsop, surface water and wildlife are not susceptible to insect and disease pests. Nehalem, and Multnomah are threatened. For maximum survival, weed control and vegetatively propagated cultivars. Six to Rooted cuttings can be easily placed exclusion of livestock are e ential the eight-inch cutting (15 - 20 cm), 1/4- to into a hole or slit formed by a dibble, hoe, fir t 2 or 3 years. All new plantings 3/8·inch- diameter (6 - \0 mm), will root auger, shovel, or planting bar. When should be inspected regularly the first readily in moist potting medium under unrooted cuttings are in erted, no more everal years to assess the need for greenhouse conditions. Slightly larger than one-third to one-half the length replacement stock or additional bank caliper (3/8 to 1/2 inch (10 - 13 mm» should remain above ground. It is repair. and longer length can be adapted to preferable to leave only two shoot buds bareroot nursery culture. Twelve to exposed. Tamping the soil firmly around Availability twenty-four-inch (30 - 60 cm) cuttings or each slip removes air pockets. lips planted directly into a treambank Willow plantings are best applied to The Soil Conservation Service, Plant will grow if adequate moisture is pre ent those , tream types or shorelines where Materials Center, Corvallis, Oregon, and proper ite preparation and planting stands would naturally occur if the site maintains foundation stock of 'Rogue' techniques are employed. Where existing were not degraded or di sturbed. They arroyo willow, 'Plumas' sitka willow, grassy vegetation is tall or water levels require careful, ite specific planning and 'Placer' erect willow, 'Clatsop' hooker are low and receding, the u e of un rooted will be not be effective in all willow, 'Nehalem' Pacific willow, and 4- to 5-foot (1.2 - I.S m) "whips" may circumstances. For example, where 'Multnomah' Columbia River willow for increase survival. They should have a stream velocities are more than 10 feet distribution to commercial nurseries, 3/4- to I-inch-diameter (19 - 25 mm). per second or the toe of the slope is arboretums, wetland scientist , and other Carefully weeded, fertilized, and unstable, revegetation may only work in researchers. Planting tock for irrigated mother plants or "cutting combination with structural measures. conservation use is available from blocks" are the best ource of healthy Certain unstable slopes may also be commercial nurseries in the Pacific ramets. Cuttings and whips should be suitable for wattling or other quasi- Northwest. taken in the winter and stored in a cooler vegetative treatments. In all ca e , at 35 to 38 OF (2 - 4 0c) until outplanted riparian plantings should be part of a Related references in spring. The top 2 to 3 inches (5- 8 comprehensive stream corridor cm) can be dipped in white latex paint or management plan. "Propagation of Willows and Poplars. " paraffin wax to identify the aerial end and For traditional vegetative streambank Plant Materials Technical Note No. I. reduce moisture loss. With these six stabilization, high density plantings on a USDA, Soil Conservation Service, varieties, there is no advantage to treating 2- by 2-foot (60 by 60 cm) spacing are Portland, Oregon. March 1989. 3 p. the cuttings with a rooting hormone. generally recommended, beginning at Another option is to establish a waterline and proceeding to the top of the "Wattling for Hard-Io-Stabilize Slopes." densely spaced, permanent willow bank. Total width on each side of the Plant Materials Technical Note. No.5. plantation and manage it to produce pole stream should be no less than \0 feet (3 USDA, Soil Conservation Service, ize stems and large branches by m) for erosion control. The wider the Portland, Oregon. March 1989. 4 p. coppicing (hardwood tand regeneration shrub lining, however, the less vulnerable through natural resprouting). This the site is to the scouring action of flood "Streamside Revegetation." Plant method could be used to supply readily waters. In addition, many indigenous Materials Technical Note No. 6. USDA, available, high quality material for such wildlife populations require wider tream Soil Conservation Service, Portland, slope protection measures such as corridors for good habitat. As a ru le of Oregon. March 1989. 8 p. wattling, brush-layering, and brush thumb, the zone should be at least 160- matting. feet wide (49 m) (80 ft on each side). "Identification ofTen Willows Used for Conventional riparian plantings For Class I streams, the Oregon Streambanks in the Pacific Northwest. " should be done a early in the spring a Forest Practices Act requires that a buffer Plant Materials Technical Note No. 11 . possible using dormant stock: either zone three times the width of the body of USDA, Soil Conservation Service, fre h, hardwood cuttings, I-year old water must be maintained for protection. Portland, Oregon. January 1990. 17 p. rooted cuttings, or bareroot stock. The This zone cannot be less than 25 feet (8 larger whips can be planted in winter as m) wide per side, but it does not need to "Stream bank Rehabilitation in Washing early as November. Competing be more than 100 feet (30 m). ton Using WiLLow Species and Hybrid vegetation should be minimized by Consider establishing an understory Cottonwood." Plant Materials Technical localized scalping or scarification of the of less competitive grasses and legumes Note No. 21. USDA, Soil Conservation oil surface. Another ite preparation and using several willow varieties along Service, Spokane, Washington. option for planting is to spot treat with an with other riparian shrubs such as redosier September 1990. 3 p. 15