May 6th, 2015 by Soest Gardener, Riz Reyes
The peony has been a staple in gardens for hundreds of years and the UW Botanic Gardens has a wonderful representation of the genus this month at both the Washington Park Arboretum (WPA) and the Center for Urban Horticulture (CUH).
This month we are highlighting a spectacular peony that’s currently in bloom in the Pacific Connections Entry Gateway. Visitors stopped in their tracks by the large, dinner plate-sized blooms which emit a wonderful scent. This is a pink form of the typically white flowered P. rockii. Found in Northwest China in Gansu Province. This species is characterized by a deep purple pattern in the center of each petal.
This type of peony is referred to as a “Tree Peony” by most gardeners. Although it’s not technically a tree, it is a woody shrub that does not die back and should not be cut down in the autumn like the more common bush peonies many people know. But like the bush form, it takes a few years before the plant is established and starts blooming well.
Both types are generally planted in the fall, but potted plants can be purchased and planted just about any time of year (except when the ground is frozen).
Genus species: Paeonia suffruticosa subsp. rockii
Common Name: Rock’s Peony, Joseph Rock Peony, Ziban Mudan
Location: WPA – Pacific Connections – China Entry Garden
Origin: NW China, Gansu Province
Height and Spread: 5-7′ height x 6′ width spread on mature, undisturbed plantings
Bloom/Fruit Time: April-May
March 3rd, 2015 by Soest Gardener, Riz Reyes
The manzanita is one of the most iconic of all West Coast native trees and shrubs, yet they are rarely ever seen in gardens. Like their famous relative, Arbutus menziesii (The Pacific Madrone), they’ve earned a reputation of being slow and difficult to establish. But with a strong emphasis in introducing more of our native flora into our gardens and the constant demand for drought tolerant plantings, the wide range of Manzanita species and hybrids have really started to come to the fore and gardeners are rediscovering their unique and stately presence in the landscape.
We have several specimens slowly getting established the Center for Urban Horticulture’s McVay Courtyard and one of the standouts is A. densiflora ‘Sentinel’. An upright grower discovered in Sonoma County, CA, it is one of the faster growing selections and it is also one of the most adaptable of the genus. The clusters of pink-to-white, urn-shaped flowers appear in later winter into spring like many in the genus, but the year round attraction is the evergreen foliage and the smooth and dramatic trunks with the often peeling, russet red bark. The older the specimen, the better they become.
Manzanitas require full open sun and very well drained soil that’s relatively lean. Avoid adding too much organic material to your soil and though they are drought tolerant, regular irrigation and fertilizer the first 2-3 years will get them going. They highly resent heavy root disturbance so take care when planting and avoid having to transplant it once its established in the ground. Staking of younger plants during planting is beneficial until they fully root in and settle.
Genus species ‘Cultivar': Arctostaphylos densiflora ‘Sentinel’
Common Name: Sentinel Manzanita
Location: McVay Courtyard – CUH
Origin: CA, USA
Height and Spread: 4-6′ height x 6′ wide
Bloom/Fruit Time: Late February-March
December 1st, 2014 by Soest Gardener, Riz Reyes
Looking nondescript throughout most of the year, the so-called “Christmas cactus” puts on a tremendous show as the holidays arrive in November and December.
As part of the Cactus family, they are actually epipthytic plants (similar to air plants) that grow on rock crevices and trees in the wild and require a well drained potting mixture and specific dry rest periods in order to initiate flowering when grown as a house plant.
Most receive a Christmas cactus as a blooming gift for the holidays. They can be enjoyed anywhere in the home where it receives bright, indirect lighting, humidity and very sparse (about once every two weeks) watering. Following the tremendous floral show, plants will rest and watering is greatly reduced further until about March or April when they can be re-potted if desired (although they prefer the tight confines of being potbound in a small container). New growth resumes and regular watering and fertilizing (all purpose fertilizer is fine) can take place (once every week or two). They can also sit outdoors up against the house protected from direct light during the summer and can be treated like other container plants.
To initiate flowering again:
Water is withheld as days get shorter and temperatures begin to drop. They need a cycle of normal daylight and then complete darkness for 12-14 hours for about 6 weeks. All this usually begins around September into October where you can either start bringing them indoors in a room that will be completely dark for that period of time or they can stay outdoors and make sure street lights aren’t disrupting this dry/dark period. If temperatures are expected to drop below 55F, then the plants should be brought inside.
After this treatment, buds should have formed and regular watering and care (once every one or two weeks) can resume as they begin to open and flower.
A bright, deep pink Schlumbergera begins to show off amongst the tropicals just as you enter the Douglas Conservatory.
species: × buckleyi (T.Moore) Tjaden = S. russelliana × S. truncata; S. Buckleyi Group is the most common.
Cultivar: Assorted named cultivars exist, but often offered by color only
Common Name: Thanksgiving/Christmas Cactus, Zygo-Cactus
Location: CUH Douglas Conservatory Entry
Origin: Wild species originate from SE Brazil
Height and Spread: 1.5-2′ high with stems that can drape 3-4ft. long
Bloom/Fruit Time: November-early January
September 4th, 2014 by Soest Gardener, Riz Reyes
Tickseed is the common name for the cheery and colorful Coreopsis. Long utilized as a border plant in perennial gardens, it’s often only know for its ferny green foliage and one main flush of bright yellow blooms in early summer. Now, thanks to Darrell Probst’s spectacular breeding work on the Big Bang series, the genus has been revolutionized, with a wider range of colors with almost continuous bloom throughout the season! Skagit Gardens in Mt. Vernon, WA has sent us samples over the years to display and trial here at UW Botanic Gardens and we have them peppered around the Center for Urban Horticulture.
This stunning selection is ‘Star Cluster’. It probably has the tidiest habit of all the Coreopsis we have. It has worked very well as a edging plant because it stays fairly low and it has been in flower since June with minimal deadheading. The color progression of the flowers is quite fascinating as it opens to a lovely cream with a crimson center and over time and as the weather cools for autumn, the center color softly blends and becomes more prominent on the entire flower.
Common Name: Tickseed
Location: Soest Garden Bed 5
Origin: Garden Origin.
Height and Spread: 15-18″ wide and 10-12″. tall
Bloom Time: June-Frost
August 4th, 2014 by Soest Gardener, Riz Reyes
Succulent plants continue to be very popular amongst gardeners everywhere because of their unusual and architectural forms and thriving with very minimal watering. The Aeoniums are one of the most iconic of all succulents. Unfortunately, they are not hardy in the Pacific Northwest, but they are excellent container specimens that are actually pretty easy to overwinter if cared for properly indoors.
The key to success with any succulent is bright light, very well-drained soil and limited watering during the growing season. They respond to being fertilized on a regular basis during active growth (for us it’s June-September) and then as cold temperatures approach, they are dug up before the first frost and potted up and kept indoors where it can stay cool, but not freezing. Some growers overwinter them “bareroot” and will mist them occasionally so they don’t dry out. The more light you can give them during this pseudo-dormant period the better.
species: arboreum var. atropurpureum
Common Name: Tree Aeonium, Irish Rose, Houseleek
Location: Containers in Soest Garden
Origin: Straight species from Canary Islands, but this selection may be of garden origin.
Height and Spread: 1.5ft wide to 2ft. tall (potentially much larger in milder climates)
Bloom Time: N/A for Pacific NW outdoors (but may flower later winter/early spring if greenhouse-grown)
June 3rd, 2014 by Soest Gardener, Riz Reyes
The beginning of June boasts boisterous and abundant blooms and this native shrub is no exception. Starting in late May, an otherwise nondescript shrub begins to draw attention as masses of single white flowers suddenly begin to pop open creating a blizzard of deliciously scented clusters that cover a straggly shrub from top to bottom.
P. lewisii growing in the upland forest restoration site out in UBNA.
Found in open forests in low-mid elevations, Philadelphus lewisii is highly adaptable to the garden where it becomes a large shrub and requires only well-drained soil, moderate moisture, and full sun to part shade. It seems to tolerate competition from other plants very well, but requires some pruning to keep its size in check and to remove dead or non-productive wood.
A established specimen in full bloom along the entrance into UBNA
Common Name: Lewis’s Mock Orange
Location: Union Bay Natural Area
Origin: Pacific NW Native
Height and Spread: 6-7′ tall and about 5-7′ wide
Bloom/Fruit Time: Late May – Early July
April 3rd, 2014 by Soest Gardener, Riz Reyes
Spring flowers are in abundance in April, but very few possess the charm and delightful scent of the infamous lily-of-the-valley. Known to be a thug in the garden once established, a variegated selection appeared that seemed to not grow as quickly. Still quick to spread in rich, moist soil and capable of competing with neighboring plants, the thin yellow striping along the leaf is quite unusual and can light up shady areas both before, during and after bloom. The only caveat to growing this plant is its tendency to revert back to all-green foliage. Once this is encountered, simply yank out the green reversions to maintain excellent foliage color.
Common Name: Variegated Lily-of-the-Valley
Location: Soest Garden Bed 7
Origin: Garden Origin
Height and Spread: 6-8″ tall and can spread forming patches in the garden.
Bloom/Fruit Time: April-May
February 4th, 2014 by Soest Gardener, Riz Reyes
Hellebores are very popular winter-blooming perennials, and plant breeders are responding to the high demand for easy maintenance and colorful blooms during the gloomiest time of the year. The Gold Collection® is an assortment of species and modern hybrids selected for vigorous growth and prolific blossoms year after year. ‘Merlin,’ a Ballardiae hybrids (H. niger x H. lividus), is simply magical: it opens as a soft pink with a deeper pink reverse and a hint of lime green. As the flower ages, the blooms age to a richer deep pink and hold on for many weeks. The foliage on ‘Merlin’ is exquisite, with a hint of marbled variegation on tough, clean leaves.
Skagit Gardens in Mt. Vernon, WA kindly donated a batch of Helleborus x ballardiae Gold Collection® ‘Merlin’ to UW Botanic Gardens, and the plants have done well for us. They’re exceptional in the garden, but also in containers for those who don’t have much space.
Common Name: Hellebore hybrid
Location: Entry Triangle Bed Entry along NE 41st St.
Origin: Garden Origin.
Height and Spread: 10-12″ high x 18″ wide
Bloom/Fruit Time: December-March
January 6th, 2014 by Soest Gardener, Riz Reyes
A striking addition to any landscape, this golden Monterey Cypress is quite popular and widely available in nurseries and garden centers. ‘Goldcrest’ is noted for its narrow, upright habit and exquisitely bright color; it fits into many different planting situations especially in smaller spaces.
The caveat to this beauty is its semi-hardiness in the Pacific Northwest. It requires a warm spot in the garden or it is best confined to a container planting that could be moved during a hard, cold winter. Most plants sold in garden centers are small, immature trees with very tender, needle-like foliage, and have a wonderful citrus scent when rubbed. They’re wonderful as a vertical accent in a container and are frequently sold decorated with ornaments during the holiday season.
They should be grown in full sun and have well draining soil. Once established, they are quite drought tolerant and often they turn slightly orange or light brown during the winter time, resuming chartreuse coloration once the weather warms in spring.
Common Name: Goldcrest Monterey Cypress
Location: Containers in Fragrance Garden
Origin: Garden Origin. Original species is native to the central California coast, USA.
Height and Spread: 6-7′ high x 18-24″ wide
Bloom/Fruit Time: N/A
December 2nd, 2013 by Soest Gardener, Riz Reyes
This low growing, creeping shrub often gets overlooked throughout most of the year, but its vibrant fruit and evergreen foliage make it a stunning addition to the winter garden, particularly in containers. The Wintergreen grows via shallow underground rhizomes and like most plants in the Ericaceae, it prefers acidic soils and because of its diminutive size, grows best in mostly sunny and exposed sites.
American Wintergreen is best utilized in container plantings here in the Pacific Northwest as large patches of it in the garden are rarely encountered. It can be a tricky plant to get established in the garden and requires regular watering initially, but looks to be drought tolerant once it gets going.
As a container plant, the lovely (and edible) fruit are closely admired and last for many weeks. The fruit itself is actually a dry capsule and it’s the fleshy red calyx that surrounds it that looks like the fruit. When crushed, it has a minty aroma.
Common Name: Teaberry, American Wintergreen
Location: Containers by the commons and Merrill Hall
Origin: Eastern North American
Height and Spread: 3-8″ high x 10-12″ wide
Bloom/Fruit Time: September-March