Native Woody Plant Propagation

Native Woody Plant Propagation

Amy Bartow & Annie Young-MathewsUSDA-NRCS Corvallis Plant Materials Center

January 15, 2019

OverviewChoosing the best propagation method for

native trees and shrubsWinter twig identificationPropagation techniques Dormant hardwood cuttingsStarting plants from seed

Propagation types

• Propagate your own– Unrooted dormant hardwood cuttings– Seed

• Purchase– Plugs/container stock– Bare-roots

Should you propagate your own plants?

• Access to propagation material• Number of plants you need• Out-planting method/tools• Resources

– Money– Space– Time– Materials– Enjoyment

Access to seed or cuttings• Availability for purchase• Locating parent material• Permission/permits• Timing

Cuttings vs. SeedCuttings• Quick and easy to plant• Eliminates the need to

care for containers for a year

Seed• Preserves genetic

diversity• Only option for species

that don’t root well from cuttings

• Only works well for certain species

• Genetic clones of parent material

• Requires more resources & time

• Containers & media• Space w/ adequate growing

conditions• DAILY watering in the

summer• ~1 yr seeding to out-planting

Considerations for Containers• Economies of Scale

– Generally costs go down per plant as more plants of the same type are grown

• Species Diversity– 20 plants of 5 species vs. 5 plants of 20 species– ↑ diversity → more complex management

• temperature, water, light requirements

PMC Tech Note 30: Ability of Pacific Northwest Native Shrubs to Root from Hardwood Cuttings (with Summary of Propagation Methods for 22 Species)

Species that root well from live stakes• Willows• Black cottonwood• Western redosier dogwood• Pacific ninebark• Douglas spirea• Twinberry honeysuckle• Common snowberry• Lewis’ mock orange• Salmonberry• Red elderberry• Indian plum• Redflower currant

Excellent (>90%)

Good (70-90%)

Fair (40-70%)

Plants to purchase as bare root stockFleshy berries w/ seed dormancy:• Black hawthorn• Cascara• Serviceberry• Crab apple• Roses• Oregon grapes• Chokecherry• Bitter cherry• Thimbleberry• Blue elderberry

Slow growers or seeds w/ difficult dormancy:• Pine• Western red cedar• Vine maple• Oregon white oak

Photo from Hanson’s Northwest Native Plant Database www.northwestplants.com

Photo from www.windward.org

kaliumtech.com hdit.co.uk

Some useful twig anatomy

• There are some other twig arrangements out in the world but these are what you are most likely to run into here.

homeguides.sfgate.com

Twigging the age of a twig

• Terminal bud scale scars often mark a year of growth.

• Bark is typically less smooth and brightly colored on older growth.

Suckers and water

sprouts

hort.ifas.ufl.edu

• These are good places to look for cuttings

• Trees, and large or older shrubs

• Fallen, living trees and branches laying along the ground can be a good source

Twig Identification

Willows (Salix spp.)• Small to large trees and

multi-stemmed shrubs, suckering and non-suckering

• There are many kinds

• Can be challenging to identify to species, it requires the male and female catkins (flowering-fruiting structures)

• Focus on matching the willow type to your target habitat

Salix species twig ID• Buds are

alternate and covered or capped with a single bud scale

Black Cottonwood (Populus balsamifera ssp. trichocarpa)Large tree to 160 feet tall!

Laspilitas.comvancouverislandbigtrees.blogspot.com

Black cottonwood twig ID• Buds are alternate, medium to large,

conical, and elongate• Twigs sometimes with vertical ridges

(tend to be more pronounced on water sprouts)

Redosier dogwood(Cornus sericea)• Open, rounded, multi-

stemmed medium to large shrub, 7 to 10 feet tall.

Redosier dogwood twig ID• Slender, very pointed

opposite buds • Bark on younger twigs turns

reddish or red-green in winter • Lenticels are raised and

prominent

Pacific ninebark(Physocarpus capitatus)

• Medium sized, upright shrub, 6 to 14 feet, multi-branched from a central base.

Pacific ninebark twig ID• Medium sized, alternate

buds.• Brown, orange, to reddish

orange, thin peeling bark.• Drooping clusters of dark

brown remnant fruiting structures.

• Oceanspray flowers also linger but look different.

Douglas spirea(Spiraea douglasii)• Grows in moist, open

sunny places, like bogs, swamps, stream and lake shores. 6 to 12 fttall, many stemmed and aggressive. Attract pollinators and birds.

Douglas Spirea twig ID

• Small, silvery-white alternate buds, often distinctly tipped with white hairs

• Stiff, upright, conical shaped, dense flower clusters that occur at the end of new growth will appear dried and dark brown in winter

Twinberry honeysuckle or black twinberry (Lonicera involucrata)

• Small to medium sized deciduous shrub 3 to 12 feet tall with an erect to straggly or arching form; more compact at higher elevation.

Twinberry honeysuckle twig ID

• Small opposite budson twigs that are smooth and light tan to brown with a “dead” appearance in winter.

• Twigs generally angled in cross-section.

• Occasionally the dead bases of the flowers linger and they can be helpful in identification.

©Ben Legler 2006

Common snowberry(Symphorocarpus albus)

• Shrub 2 to 5 feet tall, slender erect new shoots, and very branched older stems, sometimes vining growth as a response to deep shade.

Snowberry twig ID• Tiny opposite buds on grey twigs

that are often very fine and brittle.

• Look for the old fruit (soft berry) clusters at the end of twigs; they may be white, yellow, or decayed (black).

• Pith dark colored or hollow.

Lewis’ mock orange(Philadelphus lewisii)

• 4.5 to 12 feet tall, multi-stemmed shrub.

• 2- to 4- inch diameter fragrant white flowers in summer.

Lewis’ mock orange twig ID• Inconspicuous

opposite buds.• Dull grey to brown

twigs with bark that shreds with age. Soft, white “pithy” interior of stems.

• May be confused with snowberry and twinberry honeysuckle.

• Snowberry has dark colored pith or hollow stems, and often retains berries in winter.

• Twinberry twigs are generally angled in cross-section & buds are larger.

Red Elderberry(Sambucus racemosa)• Deciduous shrub or

small tree 10 to 30 feet tall, broad and arching with cane-like stems.

Blue elderberry flower in flat-topped bunches.

Red elderberry twig ID• Large, egg-shaped to

pointy opposite, purple to green scaled buds.

• Raised lenticels (pores) on stems.

• Red has 3 bundle scars in the leaf scar; blue has 5.

©Brian Legler, 2016

Blue elderberry

Salmonberry(Rubus spectabilis)

• Small to medium caneberryshrub 3 to 12 feet tall.

Salmonberry twig ID• Weakly attached

thorns.

• Zigzag branching pattern.

• This is a suckering shrub.

Indian plum(Oemleria cerasiformis)• Multi-stemmed

deciduous shrub to small tree, up to 15 feet in height.

Indian plum twig ID• Alternate round twigs;• Chambered pith (with

partitions)• Bud scales more layered and

rounded than scales on red flowering currant

• Crushed leaves and swollen buds have a “cucumber” scent

Redflower currant(Ribes sanguineum)

• Deciduous, thornlessshrub with upright spreading form, up to 9 ft. Tubular red flowers.

http://www.nwplants.com

Redflower currant twig ID

• Rosy red alternate buds that swell in late winter to expose green “leaves”.

• Dead flower and berry stem can still be attached and help to get a positive id.

• Buds are often on short spur branches on second year wood. Bark on younger twigs is red to grey.

• Lacks round lenticels found on Indian plum

Poison Oak(Toxicodendron diversilobum)

• Leaves: 3 oblong shiny leaflets (“leaves of 3, let it be”). Edges can be smooth, wavy, or lobed. Dark green color becomes bright red in the fall.

• Flowers: Very small and inconspicuous. Oblong clusters of small white flowers; blooms late spring.

• Fruit: Small berries are cream or brown.

• Growth habit: Deciduous vine or shrub, growing up to 8 ft tall. Stems are round and reddish or grey.

©2005 Lawrence M. Kelly, https://bioweb.uwlax.edu

Poison oak twig ID

• Twigs branch out at 45°angle.

• Lenticels visible or raised

• Leaf scars at base of twig

• Occasionally clusters of shriveled up berries still linger.

• Alternate buds and twigs.

Sources of cuttings

• Private landholdings, neighbors, friends, timber companies. Ask around and get permission.

• Ask about collection permits for public land managed by: US Forest Service, BLM, Oregon Department of Forestry, city or county parks

• Soil & Water Conservation District native plant sales

• Native plant nurseries

Resources for further study

• Washington Native Plant Society (Burke Museum of Natural History and Culture) Winter Twig Identification Key -http://biology.burke.washington.edu/herbarium/imagecollection.php?Page=wintertwigkey.php

• Winter in the Woods: A Winter Guide toDeciduous Native Plants in Western Washington. WSU Cooperative Extension Service. Thurston Co.

Twig Identification Practice

Growing Your Own Trees and Shrubs From Dormant Cuttings

Its as easy as putting a stick in the ground…..

Vegetative propagation

• Several types which use parts of stems, leaves or roots

• Hundreds of native woody species in Oregon can be vegetatively propagated.

• Focus here is on dormant unrooted woody stem cuttings also called hardwood cuttings.

• Planted directly in the ground!

List of recommended species• Willows• Cottonwood• Red-osier dogwood• Pacific ninebark• Snowberry• Douglas spirea• Black twinberry• Red elderberry• Mock orange• Indian plum• Salmonberry• Red-flowering currant

Before you cut!• Decide on species and numbers• Find plants to collect from and get

permission/permits (best to do this in summer, not a week before you want to cut)

• Consider genetics: find plants that are growing in an environment similar to what you want to plant them in. Cut from multiple plants.

• Plan to take cuttings and plant them immediately.

• Be prepared for post planting care and maintenance

Before you cut!• Look for vigorous, healthy

plants that have been cut back in the previous 2-3 years.

• These plants will have the young, straight growth needed for cuttings.

• Straight growth is important for planting

• Youth is important for success in rooting

Hardwood cuttings- Timing• Take cuttings after leaf fall but before

new shoot emergence in early spring. (Nov- Feb)

• The earlier you plant, the more root growth can happen before the cuttings leaf out in the spring

• More roots= more growth in year 1• Plants need less water because they

have more roots

Figuring out age classes

• 1 year- straight, usually with no branches– Brightly colored bark with

thorns• 2 years- set of branches off the

main stem– Paler, peeling bark, few

thorns• 3 + years- a set of branches off

the branches on the main stem– Dark bark, no thorns,

lichens and moss

Willows and cottonwoodsThese species are the most successful, 90% of cuttings will root and grow into a shrub or tree.

• Willows!– Pacific- nice yellow stems,

smaller, slightly brittle– Sitka- great, all-purpose willow– Scoulers- more drought tolerant

• Black cottonwood- (these get big!)

The ideal cutting-willows/cottonwood

• Straight, with no side branches• 3 ft long• Approximately the diameter of your

thumb, ideally the tip no smaller than your pinky.

• Studies show that larger diameter material (3/4”-1” )has highest survival and cover after three years.

• Larger material can be more difficult to plant.

Other shrubs to consider..Not as successful as willows, but still

very good

• Redosier dogwood• Pacific ninebark• Snowberry• Douglas spirea• Black twinberry

The ideal cutting• Red-osier dogwood- like a willow, just slightly thinner ½” – 1”

thick in diameter

• Pacific ninebark- in our studies, 2-3 year old wood is more successful than current year wood. Aim for a diameter of 1/4”-1/2” (they just have smaller stems)

• Twinberry- ¼”- ½” diameter 3 feet long (if possible)

• Snowberry- naturally have thin stems aim for the thickest ones you can (maybe a ¼”?) , 3 ft would be ideal, but usually 18 inches long is more reasonable.

• Douglas spirea- also have thin stems, aim for ¼” diameter 18”-36” long

A few more species….These aren’t as successful as the other species, but still do well. Especially with some shade and extra water the first year. Plant 2-3 cuttings at each planting spot to ensure at least one cutting survives• Red elderberry• Mock orange• Indian plum• Salmonberry• Redflower currant

The ideal cutting• Red elderberry- tricky….. Attempt

to get a 3ft cutting with at least three sets of nodes. ½” + in diameter

• Indian plum- aim for at least ¼”

• Mock orange- aim for at least ¼”

• Salmonberry- 3 year old stems are less successful than 1-2 year old stems- aim for ¼”+

TipsKeep track of top and bottom ends• Top ends are cut flat and bottom end angled.• For direct planting on project sites, some paint

the top ends…color code species, keep the top ends up!

• Keep cuttings cool and moist and plant immediately or ASAP

Outplanting cuttings• Plant cuttings at least 2/3

length below ground.

• May need pilot holes –rebar, steel rods.

• Use rubber hammers/mallets and/or protect the tops of unrooted cuttings. Dead blow hammers are “best”.

Tips for success post-planting• Apply mulch!• Remove weeds• Irrigate the first year

Tips for success post-planting

• Consider protecting cuttings from animal damage (voles, deer, etc.)

• Options: fencing, repellents, tree guards, hardware cloth, tubing,

Growing Your Own Trees and Shrubs From Seed

It’s easier than you might think…

Easy to grow from seed

• Oceanspray• Hazelnut• Ash• Bigleaf maple• Alder

1. Sow in fall2. Passive stratification

(overwintering)3. Spring germination4. Summer care5. Fall/ winter outplanting

Resources for propagation Info• The Woody Plant Seed Manual

http://www.rngr.net/publications/wpsm• Nursery Manual for Native Plants: A Guide for Tribal Nurseries

http://www.fs.fed.us/rm/pubs_other/wo_AgricHandbook730.pdf• Raising Native Plants in Nurseries: Basic Concepts

http://www.fs.fed.us/rm/pubs/rmrs_gtr274.pdf• Native Plant Network Propagation Protocol Database

http://npn.rngr.net/propagation/protocols• Grow Your Own Native Landscape, A Guide to Identifying,

Propagating and Landscaping with Western Washington Native Plants by Michael Leigh. WSU Coop. Extension Service. 1999.

• Gardening with Native Plants of the Pacific Northwest: An Illustrated Guide by Arthur R. Kruckeberg

Scout for seed sources• Your property• Neighboring properties (with

permission)

• Seed is available for purchase from a few vendors-

Inside Passage (mostly Washington sources) http://www.insidepassageseeds.com/

Jonny Native Seedhttp://www.jonnynativeseed.com

Seed collection 101• Dryness• Color• Ease of removal

from the parent plant.

Oceanspray seed collectionSeed should be collected when the achenes turn brown in the fall (September)Hand strip from shrubs and store in a dry place in paper bagsClean seeds by rubbing over a screenSeeds can have low germination % BUT they are small and plentiful, so seed heavilySeed stores well

Hazelnut seed collectionSeeds are ripe when they are brown and dislodge easily from their jackets/hullsMay be possible to bag developing nuts with mesh sacks until seed is ready to keep it safe from wildlifeCheck for viability by placing in a bucket of water. Bad seeds will float.Sow soon after harvestcalphotos.berkeley.edu

Alder seed collectionMost of the viable seed is in the upper 1/3 of the canopyCones ripen throughout October and NovemberSeed is brown when ripeCollect seed by gently shaking the tree and allowing seed to fall on tarp Seed stores well

Big leaf maple seed collection

Seed ripens during Sept and OctoberSeed dispersal occurs October through JanuarySeeds are ready when samaras turn brown and crispy and start falling off the treeCollect from groundSow right away

Ash seed collectionCollect and handle the same as big leaf maple

Samaras tend to stay on tree longer than big leaf maple

Choose your containers

At the PMC, we use Ray Leach stubby conetainers and 10 inch Deepots for container production of shrubs and trees.

Choose your containers

• Consider the size of the plant/depth of roots

• How long will it remain in container• Consider how you’re going to plant it• Consider care, storage and handling

of container plants

Choose your media

• Any general purpose bark or peat based potting media will do

• We use Pro-Mix BX compressed bales

• Hold off on the fertilizer

Sources for Supplies

• Grower’s Nursery Supply Inc. 3695 Clausen Acres Ln NE Salem, OR 97303 (503)393-6411

www.growers-inc.com

• Stuewe & Sons Inc. 31933 Rolland Drive Tangent, OR 97389 (541)757-7798

www.stuewe.com

Seed your containersSow seeds at a depth of 3x the width of the seed

Cover with vermiculite or more potting media

Alders need light to germinate

Protect from slugs and mice

Watering• Easy in winter and spring!• Not so easy all summer• Consider automatic systems • Add shadecloth to reduce

summer water stress (and deer protection)

• Larger containers usually need less frequent watering.

Fertilizer and Protection

• We use 20-20-20 water soluble fertilizer

• Organic “water in” fertilizers

• Slow release ones for top dressing.

• Slugs- can decimate young plants.

• Deer- need physical barrier.

Success!!Plant the containers out in the fall once the soil is saturated by rain.

Questions?Please feel free to contact us any time:

Corvallis Plant Materials Center(541) 757-4812

Anna.Young-Mathews@or.usda.govAmy.Bartow@or.usda.gov

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