November 2011 Plant Profile: Acer griseum

November 13th, 2011 by Soest Gardener, Riz Reyes

Fall color this autumn has been truly exceptional and this wonderful maple is no exception. Though more well known for it’s papery bark, Acer griseum is one of the most beloved landscape trees here in the Pacific Northwest. You see it more frequently these days as street trees and main specimen subjects in small urban gardens because of it’s slow-moderate growth rate.


Here it is just a few months ago. What makes this maple so distinct and easy identifiable is the bark, of course, but the foliage isn’t palmately dissected like the Japanese maples, but instead it’s a compound leaf with several leaflets.

Acer griseum fall color
Come fall, the foliage takes on a spectacular orange/red color that’s more pronounced when planted in full sun, but since this adaptable plant also thrives in part sun, the fall color is more yellow.

My friend Sean Barton with one of the largest specimens of Acer griseum I've ever seen at Bodnant Gardens in Wales, UK during a visit earlier this spring.

Common Name: Paperbark Maple
Family: Sapindaceae
Location: North of Merrill and NHS Hall
Origin: SW China
Height and spread: 18-20ft. high and 15-18ft. wide. Older specimens will ultimately reach 40-50ft.
Bloom Time: Early June
Bloom Type/Color/Fruit: Almost inconspicuous flowers appear in spring followed by dull green samaras appear in mid-summer.

October 2011 Plant Profile: Vitis coignetiae

October 4th, 2011 by Soest Gardener, Riz Reyes

Vitis coignetiae

Another woody plant has captured our attention this month and is deserving of this autumn highlight and that’s the Crimson Glory Vine.

While most grapes are fruiting now and express some fall color, this outstandingly large and colorful vine is mesmerizing to see especially when back lit by the western exposure of the sun. A entire kaleidoscope of rich purples, bright crimsons, yellow, reds and oranges along with the aging green is a sight to see.

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It is readily available and fairly easy to care for. It requires full sun, but can tolerate part shade, and moderate irrigation. It also requires quite a bit of space, but responds pretty well to pruning in mid-summer to control its size and habit on a trellis or similar structure.

Common Name: Crimson Glory Vine
Family: Vitaceae
Location: North of Merrill Hall and South of Issacson Hall on trellises
Origin: Russia, Korea, and Japan
Height and spread: 20-30ft. +
Bloom Time: Early June
Bloom Type/Color/Fruit: Almost inconspicuous racemes with small white lowers later forming into chalking purple blue fruit that are slightly bitter and tart with prominent seeds.

September 2011 Plant Profile: Vitex agnus-castus

September 1st, 2011 by Soest Gardener, Riz Reyes

I’ve decided to go with a woody species this month so I selected the fabulous Chaste Tree. Our specimen here at CUH is just coming into bloom and will absolutely peak in the next couple of weeks attracting bees, butterflies, and other wildlife while also attracting the attention of our frequent visitors who inquire as to “why do you grow butterfly bush? Don’t know you know it’s a noxious weed?!”


Vitex agnus-castus makes a wonderful substitute to the agressively self-seeding Buddleja davidii. It has a far more elegant appearance with it’s scented, silvery green, palmately compound leaflets and the conical, upright flowering stems that bear lavender flowers that really look like butterfly bush.

As a Mediterranean native, it prefers a warm environment in full sun and fairly well drained soil. It is readily available in most garden centers and while the most common form is the lilac color. Vitex also comes in white and pink. Though hardy and thrives in the Pacifc Northwest, it is VERY slow to leaf out and looks like a dead tree in early summer before it begins to leaf out. Vitex comes into its own in later summer entering fall, which makes it so ideal for later season interest.


Common Name: Chaste Tree
Family: Lamiaceae
Location: Douglas Conservatory Parking Lot
Origin: Mediterranean
Height: 5 meters
Spread: 5 meters
Bloom Time: Late August-September
Bloom Type/Color: Upright panicles of lavender, occasionally white and pink forms available.

August 2011 Plant Profile: Eucomis bicolor

August 2nd, 2011 by Soest Gardener, Riz Reyes

Pineapple lilies are gaining popularity as gardeners are finally giving them a chance! Though somewhat marginally hardy and very tropical in appearance, a handful of species and hybrids do quite well here in the Pacific Northwest given that they receive excellent drainage (especially during the winter) and regular watering during the growing season. Eucomis bicolor is one of the more common and easily sought after species as it truly showcases why this genus is known as “pineapple lily”

Eucomis bicolor about to flower in late July

The strappy foliage, sometimes mottled in purple on the undersides, is attractive by itself, but emerging from the center is this alien-like creature about to invade.

Common Name: Pineapple Lily
Family: Asparagaceae
Location: Soest Garden Bed 8
Origin: South Africa
Height: 12-15″
Spread: Can form a clump 2-3 feet wide after many years
Bloom Time: Late July-August
Bloom Type/Color: Cylindrical raceme on stout stems with
cream white florets streaked in purple and unpleasantly
scented observed up close. Green bracts on top that create a “pineapple” look.
Exposure/Water/Soil:Full sun/part shade in well-drained soil. Regular irrigation.

An immature inflorescence of E. bicolor

A stem of E. bicolor in full bloom last summer in August.

July 2011 Plant Profile: Triteleia (Brodiaea)

July 10th, 2011 by Soest Gardener, Riz Reyes

Triteleia 'Rudy'

Triteleia in McVay Courtyard with Nolina nelsonii in the background.

Somewhat of a taxonomic nightmare, but truly a much overlooked summer flowering bulb! Planted as a group, these put on a colorful show in early summer as they first emerge as fleshy, grass-like plants, but then they’re soon followed by wiry stems hold up clusters of blue-violet blooms (also comes in white) that are eye-catchy and truly spectacular. The seed heads will also dry adding a little longer interest. This particular cultivar pictured is called ‘Rudy’ with a cool blue suffused in white. It thrives happily emerging from ornamental grasses and just popping up as a planned surprise. These are charming, so easy to grow and need to be used more often.

Common Name: Triplet Lily, Brodiaea
Family: Asparagaceae
Location: Soest Garden Bed 6
Origin: Western USA
Height: 10-12″
Spread: Each inflorescence is about 6-8″ wide.
Bloom Time: Late June/July.
Bloom Type/Color: Terminal umbels on wiry stems with clusters of typically blue/violet flowers,
Exposure/Water/Soil: Full sun in well-drained soil.

June 2011 Plant Profile: Glumicalyx goseloides

June 6th, 2011 by Soest Gardener, Riz Reyes

Walking down the Soest Garden, it’s very easy to miss seeing this remarkable perennial plant all the way from South Africa. It’s a low growing evergreen perennial herb with foliage that has a pungent scent to your fingers if you touch it and if you kneel down and observe the unique tubular flowers, you’ll pick up on the “artificial chocolate” scent. What is really special about this delicate plant is its hardiness. It has survived temperatures in the lower teens (Fahrenheit) provided that it’s in a well drained spot in full sun.

Common Name: Nodding Chocolate Flower
Family: Scrophulariaceae
Location: Soest Garden Bed 8 (Southeast corner of bed)
Origin: South Africa
Height: 10-15″
Spread: 12-15″
Bloom Time: Late May and throughout the summer if deadheaded
Bloom Type/Color: Terminal racemes of nodding flowers of red/orange with a unique fragrance.
Exposure/Water/Soil: Sun-Part Shade. Moderately moist and well draining soil.

May 2011 Plant Profile: Daphne x transatlantica ‘Summer Ice’

May 11th, 2011 by Soest Gardener, Riz Reyes

Having the coldest spring on record, I figured it would be fitting to introduce this excellent garden plant that might describe what kind of summer we have.

Daphne x transatlantica 'Summer Ice'

Daphne ‘Summer Ice’ is becoming a widely recognized small shrub for the Pacific Northwest. It’s dependable, easy to care for, once established, and possesses fine qualities as such persistent leaves (for the most part) and wonderfully sweet fragrance that’s present almost year round. Gardeners have been impressed with its tidy habit often forming a compact mount with dense blooms from top to bottom.

Common Name: ‘Summer Ice’ Daphne
Family: Thymelaeaceae
Location: Fragrance Garden
Origin: Garden Origin
Height: 2.5-3ft.
Spread: 3ft. wide
Bloom Time: Intermittently throughout the year.
Bloom Type/Color: Terminal clusters of white-pale pink,tubular flowers with exceptional fragrance.
Exposure/Water/Soil: Sun-Part Shade. Moderately moist and well draining soil.

April 2011 Plant Profile: Osmanthus delavayi

April 8th, 2011 by Soest Gardener, Riz Reyes
 

One of the most useful and attractive evergreen shrubs for the Pacific Northwest, this fragrant, spring blooming gem is hardy, easy to grow and highly adaptable to our climate. Left alone, it’s a loose and airy background shrub with clusters of densely packed tubular flowers in early spring. It also responds well to regularly pruning and shearing as a specimen or hedging plant. This is often done after flowering to stimulate growth that puts forth next year’s bloom.

Common Name: Delavay Tea Olive
Family: Oleaceae
Location: Fragrance Garden. McVay Courtyard
Origin: Western China
Height: 6-8ft. tall and
Spread: 10-15 ft. wide
Bloom Time: Late March into April
Bloom Type/Color: White, axillary, tubular flowers. Scented
Exposure/Water/Soil: Sun-Part Shade. Moderately moist and well draining soil.

March 2011 Plant Profile: The Genus Helleborus

March 9th, 2011 by Soest Gardener, Riz Reyes

The popularity of this tough and resilient perennial has made it one of the most revered and sought after of all winter blooming plants in our climate. The range of varieties and different color forms now available is quite remarkable and being able to select just one for your garden is near impossible.

Helleborus x hybridus Winter Jewels™ Black Diamond

By far the most popular and well known are the diverse hybrids of Helleborus x hybridus (often incorrectly dubbed as Helleborus orientalis) or the Lenten Rose. These represent the wide range of colors and forms that currently exist and some of the finest examples come from a breeder who generously donated some of their previous breeding stock to UW Botanic Gardens, which are all now in full bloom at the Center for Urban Horticulture. Ernie and Marietta O’byrne of Northwest Garden Nursery developed the fabulous Winter Jewels Series. Thousands of crosses comprised of hybrids bred from at least 16 different species make up several color strains to showcase much improved flower forms, exquisite colors and unusual markings.

Here’s just an example of their work and what’s currently blooming now:

Helleborus x hybridus Winter Jewels™ Jade Star flower reverse

Helleborus x hybridus Winter Jewels™ Onyx Odyssey reverse

Helleborus Winter Jewels™ Painted

Helleborus x hybridus Winter Jewels™ Golden Lotus

When it comes to early bloom, prolific flowers and sturdy, disease-free foliage, the new hybrids coming out of Europe are tough to beat. The “Gold Collection”, again a complex series of hybrids are actually identical clones propagated vegetatively (via tissue culture) to ensure uniformity. In varying shades of pure white, cream, to deep saturated pinks, these have proven to be vigorous and excellent garden or container perennials. ‘Joseph Lemper’ our January 2010 Plant Profile) along with ‘Jacob’ are two selections of Helleborus niger that are a part of this Gold Collection. Then you have the exquisite quality of varieties such as ‘Ivory Prince’ and ‘Pink Frost’ that are flying off the nursery tables at nurseries in mid-winter.

Helleborus 'Josef Lemper'

A brand new hybrid that was new for us last year is getting established and looking quite lovely is Helleborus x ‘Rosemary’. An unusual cross between H x hybridus and H. niger bringout the fine qualities of both plants.

Then you have the sturdiness and dependability of species such as Helleborus argutifolius, the Corsican Hellebore, which opens later in the spring with pale green flowers. A selection called ‘Silver Lace’ is lovely with finer dissected foliage and a more compact habit. Helleborus foetidus you can find growing in the Fragrance Garden despite its unpleasant smell if admired up close, The foliage is exquisitely elegant, narrow and finely dissected.

Hellebores will be the highlight of an early spring plant sale taking place here at CUH being run by the Northwest Horticultural Society. Proceeds from the sales go to support the Miller Horticultural Library and there will be plant vendors from all around the Puget Sound region selling plants and, yes, they’ve been asked to also bring their blooming hellebores to entice you! There will be demonstrations, displays, and even a talk by renowned plantsman, Dan Hinkley.

For more information, please visit our page dedicated to this event!

This is the perfect month to see these wonderful jewels in person as the weather begins to warm, the earliest of bulbs begin to pop and the color heralding the arrival of spring.

Common Name: Lenten Rose, Christmas Rose
Family: Ranunculaceae
Location: Throughout CUH
Origin: Original species come from Eastern regions of Europe. Mostly hybrids.
Height: 10″-18″ tall
Spread: mature clumps can get 2.5ft. wide
Bloom Time: Mid-Winter-Early Spring
Bloom Type/Color: Flowers composed of persistent sepals often marked or fully double with central nectaries. Flowers are out to downfacing opening sequentially.
Water/Soil: Moist to moderately dry. Drought tolerant once established.

February 2011 Plant Profile: The Genus Galanthus

February 4th, 2011 by Soest Gardener, Riz Reyes
Galanthus nivalis by R. Reyes

Galanthus nivalis in the Fragrance Garden

We have several forms of the dainty and delicate snowdrop growing here at the Center for Urban Horticulture. Of all spring emphemeral bulbs, Galanthus have been revered and loved for many centuries and have always been the harbingers of spring as their noses poke up and their gentle blossoms push through the snow. It’s quite a dazzling image.

The popularity of Galanthus have suaded plant collectors, more specifically known as “Galanthophiles”, to seek out the rares forms and long lost hybrids that mostly exist amongst growers in the United Kingdom.

Supposedly, a single bulb of a exceedingly rare variant of Galathus was sold on eBay for well over $500 as stated in this article. The facts about the actual plant and terms of sale was somehow not clear.
The exceptionally large flower of Galanthus plicatus ‘EA Bowles’ that sold for £357 at auction

Not everyone need pay close to that amount to enjoy the sparkling beauty of snowdrops in the late winter. Often you can purchase a bag of bulbs (Most commonly available species G. nivalis and G. elwesii) in the fall or purchase potted plants blooming right about now at specialty nurseries. They naturalize and multiply when left undisturbed and they thrive in sun or shade in well drained soils.

An unusual double-flowered Galanthus nivalis 'Flore Pleno'

Come see them now in full bloom here at CUH!

Common Name: Snowdrops
Family: Amaryllidaceae
Location: CUH: Soest Garden, Fragrance Garden, McVay Courtyard (double flowered forms)
Origin: Original species come from Eastern regions of Europe.
Height: 3-6″ tall
Spread: mature colonies of bulbs can cover a square foot or more.
Bloom Time: Mid-Winter-Early Spring
Bloom Type/Color: Composed of tepals prodominantly white in color with various variations
Water/Soil: Moist to moderately dry. Drought tolerant once established.

Pure white