native plant gardening through the seasons

Native Plant Gardening through

the Seasons (In the Pacific Northwest)

Linda R McMahan, Ph.D.Oregon State University

Department of Horticulture & OSU Extension Service, Retired

linda.mcmahan@oregonstate.edu

Why Native Plants?• Connect with nature• Watch and nurture wildlife-

birds, insects, mammals• Water and energy efficiency• Not invasive “at home”• Note: most examples are

from western Oregon but the concepts are adaptable to anywhere

Wild strawberry

Salmonberry

Why A Seasonal View?• Learn all phases of a plant’s

life cycle• Drive-by plant identification• Learn winter plant

identification• Learn best season to feature

the species in the gardeno I will show seasons of

plants for most or all examples throughout this presentation

Salal

Red flowering currant

An Example

Lady Fern, Athyrium felix-femina

Winter dormancy

New leaves emerge as

“fiddleheads” each spring

Stately upright form in spring

relaxing in summer

Another Example

Inside-out flower, Vancouveria hexandra

Winter dormant, emerging with soft

bright green in spring, delicate flowers

Spreading groundcover in summer

Goes dormant for winter, sometimes

with bright yellow fall color

Winter• Most difficult season to envision at

first• Many plants are dormant, leaving

only a memory or a few stray plant parts

• Look for: Evergreen foliage, contrast, form and subtlety and very early or late-- bloomers

• Bonus: a chance to learn winter plant identification!

Western sword fernAvailable from OSU Press

Evergreen foliage

Sword fern Polystichum munitum• Provides year-round garden

“structure”• Use for slopes and backgrounds• Has all season interest with

attractive foliage• Great shapes for spring frond

emergence as they “unfurl”

Evergreen Foliage

Evergreen huckleberry, Vaccinium ovatumNew foliage emerges with reddish colorSpring blooms with summer and fall berriesBonus: great wildlife plant with edible berries (a wild blueberry!)

Evergreen foliage

Salal, Gaultheria shallonNew foliage emerges as lighter greenSpring blooms with summer and fall berriesBonus: also a great wildlife plant with edible berriesA good tall evergreen groundcover

Evergreen foliage

Oregon grape, Berberis aquifoliumState flower of OregonYellow spring, early summer bloomsBonus: A great wildlife plant with edible berries

Evergreen foliage

Pacific rhododendron, Rhododendron macrophyllumSlow growing but worth the waitAttractive spring bloomsGood structural plant for part-shade, can reach 8-10 ft. or more in cultivation

Winter is the season for lichensLichens are beneficial symbiotic organisms typically made up of an algal and a fungal speciesAs fall rains appear, they swell and become more visible, especially on deciduous trees once leaves have fallen

Lichen on alder bark

Lichens on Oregon oak

Winter is the season for fallen leavesLeaving leaves on the ground adds naturally to soil fertility Can often see plant form, even reproductive structures in the fallen leaf litterProvides hiding places for insects and other wildlife

Leaf skeletonsBig-leaf maple

In late winter, look for early bloomers

Osoberry, Oemleria cerasiformisFirst wild shrub to bloom in western OregonWoodland species, shade to part-shadeSummer fruits provide food for wildlife

In late winter, look for early bloomers

Red-flowering currant, Ribes sanguiniumFebruary or early March, many color forms availableAttract hummingbirdsPart-shade to sunCan be short lived but fast growingBonus: edible berries are a bird favorite

In late winter, look for early bloomers

Snowberry, Symphoricarpos albus var. laevigatusSoft bluish foliagePollinated early, often by bumblebeesWhite berries (toxic seeds) are good winter food for birdsPart-shade preferred

In late winter, look for early bloomers

Red huckleberry, Vaccinium parvifoliumAttractive winter branches, green or black stems, tiny red blooms“Likes to” grow in decaying stumps of Douglas firBonus: edible berries also loved by birdsPart-shade preferred

In late winter, look for new foliage

Example: Oregon oak, Quercus garryana Often naes as western Oregon’s best tree for wildlifeStately slow-growing treeImportant to avoid summer irrigation as it can cause fungal root rotHost to leaf gall insects

Spring• Surprise! as plants emerge from

dormancy, some blooming early• A good time for shade-loving

wildflowers, especially before tree and shrub leaves have fully emerged

• Early pollinators like bumblebees make a good show as do overwintering hummingbirds

• Many springtime natives have fragrance and color to attract pollinators

• A good time for woodland gardens, small or large

Camas

False Solomon’s seal

A place to find names and photographs of PNW native plants

• Oregon Flora Project, Dept. Botany & Plant Pathology,Oregon State University, Corvallis, OR 97331-2902 http://www.oregonflora.org/ A nonprofit organization housed a OSU

• Has Oregon Plant Atlas to provide maps of natural distributions• Has a very wide photograph collection and accepted scientific

names—many have recently changed• Has issued a new book to be released late summer 2015 The

Flora of Oregon, Volume 1: Pteridophytes, Gymnosperms, and Monocots – other volumes to follow later

• To search go to the Vascular Plant Checklist, scroll down and select genus (alphabetically) which will take you to the family checklist which is also alphabetical

Early spring bloomers

Wild ginger, Asarum speciesSmall flowers hidden under foliage, pollinated by crawling creaturesBeautiful slow growing groundcover for moist shadeIn western Oregon, susceptible to damage by non-native slugs

Early spring bloomers

Wild sorrel, Oxalis oreganaPink and white flowering forms, pink form often called Redwood sorrelAggressive groundcover for part-shade shade-creates a carpet

Early spring bloomers

False Solomon seal, Maianthemum racemosum This and similar related species are good in shady borders or woodland gardensEarly spring color is often subtleMost require more moist environment but may become dormant during summer to avoid drought stress

Flowering groundcovers

False lily of the valley, Maianthemum dilitatum Works well in shaded moist areasSpreads slowly-faster in coastal climatesFlowers and fruits add seasonal interestProvides places for insects, amphibians, and baby birds to hide

Flowering groundcovers

Western bleeding heart, Dicentra formosaWorks well in shaded moist areas, fern-like foliageSpreads to form a mat over timeAvoids stress through winter dormancy and summer dormancy when water is scarceProvides soil water retention and places for wild creatures to hide

Flowering groundcovers

Stream violet, Viola glabellaA flowering ground cover or accent for drier areas, full to part-shadeSpreads to form a mat over timeButterfly host as are most violets

Flowering groundcovers

Wild strawberry, Fragaria speciesSeveral species for sun or shadeSpreads by runners to form an “open” ground coverButterfly host plantsMost have edible berries

Late spring interest

Oregon iris, Iris tenaxOregon wildflowers on the flashier sideDeer resistant and drought tolerantReliable in the summer border or among shrubs, several shades of purple or blueAttracts many pollinators

Late spring interest

More native iris, including Iris douglasiana (left) and the Pacific Coast hybrids (one form shown at right)Share many characteristics of Oregon irisPacific Coast hybrids are a mix of species with highly variable colors and sizes that often come with a higher price tag as well

Late spring interest

Camas, Camassia speciesReliable bulb in cultivation, thriving in many garden conditionsBlue flowers add to garden diversityEasy from seed, self-seeds over timeSeveral species commercially available

Late spring interest

Goatsbeard, Aruncus dioicus var. acuminatusReliable bloomer of high stature, 4 feet or morePart-shade to nearly full sunResembles Astilbe but taller

Late spring interest

Western columbine, Aquilegia formosaDelicate columbine for sun to part-shadeButterfly host plantAttractive for hummingbirds and butterflies

A fern with spring interest

Deer fern, Blechnum spicantEvergreen fern that produces “fertile fronds” for spore reproduction in the springSpectacular in garden settings

A surprisingly attractive plant for water gardens or wet areas

Western skunk cabbage, Lysichiton americanumStriking in springPollinated by flies, hence the odor-not really unpleasant at that

At Nitobe Japanese Garden, Vancouver BC

Summer• Summer bloomers attract pollinators

(and neighbors!) • Full sun border plants, blooming

shrubs for sun or part-shade• Berries or other fruits (some edible)

attract birds and wildlife• Mix natives into summer borders or

use at woodland’s edge• A good time to watch pollinators,

especially if you have a water source nearby. Attract bees, hummingbirds, butterflies, and many small insects

Oregon lily

Thimbleberry

Plants for sunny borders or accents

Goldenrod, Solidago speciesJuly bloomerStately and brightDrought tolerant

Plants for sunny borders or accents

Oregon lily, Lilium columbianumLate June/early July bloomerDelicate tiger lily for sun or part-shadeButterfly pollinatedPlants often expensive because propagation is slow

Plants for sunny borders or accents

Checkermallow, Sidalcea speciesJune bloomer, sometimes earlierFull sun is best, 2-4 ft.Several species, all have shades of pinkWill self-seed in the garden

Plants for sunny borders or accents

Douglas aster, Symphyotrichum subspicatum July/August bloomerFull sun if possible, drought tolerantAttracts many different kinds of beesSlowly spreads underground, offsets can be moved or used for propagation

Plants for sunny borders or accents

Oregon sunshine, Eriophyllum lanatumJuly/August bloomerFull sun if possible, drought tolerantDifferent form depending upon originUpright form has green leaves and more prostrate form has silvery leaves

Blooming shrubs for shade or part-sun

Thimbleberry, Rubus parviflorusSpring blooms and summer berriesPart-shadeBonus: Edible berries also loved by birdsSpreads underground to form patches so give it room!

Blooming shrubs for shade or part-sun

Salmonberry, Rubus spectabilisSpring blooms but summer berriesPart-shadeBonus: Edible berries also loved by birdsSpreads underground to form patches so give it room!

Blooming shrubs for shade or part-sun

Wood rose, Rosa gymnocarpa var. gynocarpaSpring/summer blooms and summer hipsPart-shadeDelicate and fragrant small flowersSpreads underground to form patches—good for woodland edge

Blooming shrubs for shade or part-sun

Oceanspray, Holodiscus discolorBlooms JulyTall shrub, great at woodland edgeSprays of tiny white flowers Drought tolerant once established

Blooming shrubs for shade or part-sun

Mock orange, Philadelphus lewisiiBlooms June-JulyFragrant white flowers show off in a shade gardenFor best form, prune from the baseDrought tolerant once established FrG

Blooming shrub for sun

Douglas spirea, Spiraea douglasiiBlooms June-July, butterfly hostBright pink flowers in a spike-showyRequires additional irrigation in drier areasFast-growing, 5-7 ft.

Succulent for containers or rock garden

Broadleaf stonecrop, Sedum spathulifolium ssp. spathulifoliumBlooms June-JulySucculent form, bright yellow flowersButterfly host plantEasy to propagate, leaf color varies

Spectacular plant or water garden or moist area

Umbrella plant, Darmera peltataBlooms in spring, often before leaves emerge, winter dormantMoist to moderately moist soil, part-shade to sunImpressively large leaves in summerSpreads by rhizomes to form a patch

Autumn• Fall color, subtle to

spectacular• Fruits and seeds• Appreciate lingering blooms• A good time to watch animals

prepare for the winter, gathering seeds, nuts, and fruits

• A time to appreciate garden “structure” and plan for the coming year

Umbrella plant

Red twig dogwood

Plants with fall color

Red twig dogwood, Cornus sericeaBlooms in spring, fruits in summer, persisting into fallMoist to moderately moist soil, part-shade to sun, for best form, prune from the baseReddish stems show best in fall/winterOften has good fall color

Plants with fall color

Vine maple, Acer circinatum Tiny spring blooms followed by samaras Grow in part shade for twining habitYellow to red fall color depending on location and individual plantDrought tolerant once established

Vine maple samaras

Plants with fall color

Big leaf maple, Acer macrophyllumStately tree, drought tolerantPendant blooms followed by samarasPale to bright yellow fall colorDeciduous so provides summer shade

• Look for more slides and information at slideshare.net. Search for my name (Linda McMahan) on slideshare.net to find other similar presentations and resources.

• Annotated list of plants native to western Oregon is at http://www.slideshare.net/lindamcmahan/recommended-native-plants-for-home-gardens-in-the-willamette-valley

• Many books are available. My favorite is Arthur Kruckeberg, 1966, Gardening with Native Plants of the Pacific Northwest, 2nd edition, University of Washington Press, Seattle, Oregon

• Look online for free!

• For woody plants (shrubs and trees), check out Landscape Plants, Images, Identification, and Information. http://oregonstate.edu/dept/ldplants/

• Visit the Oregon Flora Project http://www.oregonflora.org/

• Check resources for OSU Extension, especially for specific regions. Request information from local faculty and staff.

This ends our year in photographs of native plant gardening through the seasonsThank you!

Note: All photographs are by the author. You may use freely for educational purposes.

This slideshow is available for use freely for educational purposes. Please contact the author for more information or questions. linda.mcmahan@oregonstate.edu