Category Archives: Ornamental Shrubs/ Care

To Propagate Evergreens

Posted on by

A simple propagation method for many garden club members to do in preparation for AGC’s plant sale next spring.  

 This Information was taken out of an older August Sunset Magazine Article: 

“To propagate evergreens:  Take 5” cuttings of azalea, camellia, daphne, euonymus, holly, or rhododendron.  Strip off all but the top three or four leaves, dip cut ends into rooting hormone, then plant in 4” pots.  Put them in a bright, sheltered spot, and keep moist.  In spring, you’ll have rooted plants”.  

Prune to keep ornamental shrubs healthy

Posted on by
As winter moves toward spring, pruning jumps to the top of the gardening “to-do” list. Pruning keeps ornamental shrubs healthy by removing dead, dying and diseased wood and encourages the natural and sturdy growth of the plant.

“Pruning is one of the most important tasks to keep shrubs and bushes healthy,” explained Ross Penhallegon, horticulturalist and pruning expert with the Oregon State University Extension Service. “Yet pruning often gets neglected or forgotten.”
Basic pruning guidelines deal with the many sizes, shapes and growth forms of ornamental shrubs. Most gardeners should do some pruning each spring and/or summer if they have spring or summer bloomers, Penhallegon said. Shrubs that bloom in the early spring, such as forsythia, rhododendrons and azaleas, should be pruned when they finish blooming. Then they have the rest of the growing season to form new branches and flower buds.

Shrubs that flower in the summer and fall are blooming on this year’s growth. They should be pruned early in the dormant period or very early spring so there’s plenty of time for new growth to form and bloom.
“Sometimes it’s worth it to prune out of season and sacrifice a year of blooms,” Penhallegon said. This is the case when the bush is overgrown, has gangly branches or has been neglected for years. This type of pruning should be done in the dormant or winter time.
Light pruning can be done in the summer, when it’s easy to spot dead, dying, diseased, or weak branches with few leaves. Pruning in the winter allows you to see how the branches grow in relation to one another. Branches growing toward the center of the plant or crossing or rubbing other branches are good candidates for removal. This kind of maintenance pruning in itself reduces the size of the plant if it is too large.
If you prune regularly every year, you never need to prune too severely. Yearly pruning keeps the plant in good condition with new and old branches and some in between. If the plant grows too tall or large from lack of pruning, it can overwhelm neighboring plants and surroundings.
“A little pruning each year helps to keep the plant in bounds, keeps it healthy, allows good light penetration and encourages blooms every year,” Penhallegon said.

Shrubs can be pruned drastically if they get out of hand and need rejuvenation. Multi-stemmed species such as spirea and forsythia can be heavily pruned by removing the older stems or branches, lowering the height of the plant. Rhodies and azaleas can be heavily pruned to 12-14 inches or just above buds that are on the lower part of the plant.

An overgrown shrub with a single lead or trunk growth form needing rejuvenation should be gradually pruned down or brought under control to maintain the natural form of the plant. Don’t be tempted to shear off the top of this kind of plant. Always cut back to a good side branch. Shearing may be faster, but it will produce a leggy plant with brushy growth at the stem ends. Each cut will often produce two more branches. Some large shrubs, like laurel, will sprout from bare wood even when they’re cut back nearly to the ground. Evergreen shrubs, both broad-leafed and needled, should not be pruned back to bare wood.

—————————-
About Garden News from OSU Extension Service: The Extension Service Gardening web page, http://extension.oregonstate.edu/community/gardening, links to a broad spectrum of information on Oregon gardening, such as tips, monthly calendars, how-to publications, audio programs, the Master Gardener program and “Northwest Gardeners e-News.”

By Judy Scott, O.S.U., Corvallis Ore
Source: Ross Penhallegon, O.S.U.Extension Service

Spring: Fertilizing Trees & Shrubs

Posted on by
Spring is a good time to fertilize young trees and shrubs
By Judy Scott, judy.scott@oregonstate.edu
Source: Ross Penhallegon, ross.penhallegon@oregonstate.edu

CORVALLIS, Ore. – Trees and shrubs often are forgotten when it comes time to fertilize the yard in the spring. Young trees, especially those with a trunk diameter of less than six inches, can benefit from regular applications of fertilizer.

“When young trees soak up nitrogen fertilizer, they grow quickly, develop a dense canopy and stay green into the fall,” said Ross Penhallegon, horticulturist with the Oregon State University Extension Service. “It might not be necessary, however, to fertilize large, established trees or shrubs in or near lawns or groundcovers that are fertilized regularly.”

Tree root systems extend for a long distance and they absorb nutrients when the area around them is fertilized. Additionally, as trees mature, their roots develop associations with fungi called mycorrhizae. These beneficial fungi help the tree utilize minerals and elements in the soil.

Before you fertilize, take a look at your trees and ask these questions to help you decide if your trees need additional nutrients:

  • How much annual growth do you see? Most young trees average about 12 to 18 inches of new shoot growth each year; older trees have less.
  • Is your tree growing less than expected?
  • Has the color, size or amount of foliage changed over the past few years?
  • Has the tree recently had disease or insect problems?

If you answered yes to any of these questions, the tree might benefit from fertilization.

  • Another way to determine fertilizer needs is to do a soil test.

“The best time to fertilize is in the spring,” Penhallegon said. “If you fertilize in the fall, you run the risk of shocking the plant into becoming metabolically active right when cold weather hits.” Plus, a lot of the fertilizer will leach into the groundwater due to the excessive rain.

Most woody plants begin the new year’s growth with elements stored from the year before. An application of fertilizer in the spring gives an additional boost to this new growth.

Garden references vary about how much fertilizer to apply to trees and shrubs. Penhallegon has a general rule for fertilizing trees and shrubs – use 1/4 to 1/2 pound of nitrogen per inch of diameter for trees six inches or more in diameter at breast height. Use 1/4-pound actual nitrogen per inch on smaller trees. This is roughly two to four pounds of complete fertilizer per inch diameter on the larger trees and half that dosage on smaller trees. In most cases use the lesser amount.

“As time goes on, you will be able to tell by the condition of tree or shrub, whether or not it needs more fertilizer,” Penhallegon said. “Typically, healthy trees and shrubs have 12 to 18 inches of branch growth per year. Their leaf color should be dark green, with lighter green on new growth.”

Apply the fertilizer along the drip line of the tree, the area with the majority of the roots. If the fertilizer is applied to the soil surface only, much can be washed away or will not filter into the soil to the root zone. Water the fertilizer or allow the rain to keep the fertilizer from washing away.

For quicker absorption, use a punch or probe to make holes 12 to 18 inches deep, and then fill the holes with fertilizer. Then, be sure to water deeply.

Another way to fertilize is to “pepper” the ground with fertilizer as you walk around the drip-line of the tree. This method should also provide an adequate amount of fertilizer. Apply fertilizer in this manner right before it rains, so it will be washed into the root zone. Or water the fertilized area for an hour after application.

————————–

This article is online at: http://bit.ly/OSU_Gardening1534

For more information, see the two-page publication “Fertilizing Shade and Ornamental Trees” at http://bit.ly/OSUESfs103 or visit OSU Extension on-line publications and video catalog at http://extension.oregonstate.edu/catalog. The catalog shows which publications are available online and which can be ordered as printed publications.

Mid-Winter Madness

Posted on by

The English writer Beverley Nichols wrote in his book Down the Garden Path, “We are in the depths of winter….my first winter at the cottage…and the first winter when I went mad.” Isn’t this the feeling all gardeners have in the middle of winter when snow blankets our landscape and we stare out our windows into our gardens dreaming of vibrant multicolored flowers overflowing in our flower beds, the sweet scent of flowers filling our noses, and the sun warming our backs, as we weed.
Mr. Nichols poetically expresses a gardener’s dilemma in winter time when he writes, “ The average gardener, in the cold dark days of December and January, sits by his fire, turning over the pages of seed catalogs, wondering what he should sow for the spring.”

Does this sound familiar?

He continues writing, “If he goes out into his garden at all, it is only for the sake of exercise. He puts on a coat, stamps up and down the frozen path, hardly deigns to glance at the black empty beds, turns in again”. He says after his first winter, when he went mad, he declared he would have flowers in the winter time, real flowers, to get him through the dark cold days of winter.His friends, and neighbors, told him this desire for winter flowers was insane, he stated, “perhaps it was”, but flowers he would have.

The following are a few of the winter flowers he grew to get him through until spring.

Winter Flowers

Helleborus niger……. Christmas rose

The Christmas rose is a traditional cottage garden favorite. It bears its pure white flowers (which fades to pink) in the depths of winter. They should be planted in partial shade, preferably under deciduous trees, which gives them winter sunlight. Plant in fertile, well-draining moist soil and protect them from strong winter winds. Height 8” USDA Hardiness Zones 3 to 8

Galanthus nivalis……Common Snowdrops

The common snowdrop looks like three drops of milk hanging from a stem. It is a bulbous plant in the Amaryllis family. Most flower in winter, before the vernal equinox (March 21st in the N. Hemisphere), but certain species flower in early spring and late autumn. Some snowdrop species are threatened in their wild habitats, and in most countries it is now illegal to collect bulbs from the wild. Good for mass plantings.
Height: less than 6″ USDA Hardiness Zones 3 to 8

 

Galanthus elwesii…Giant Snowdrop

Giant clear white fragrant flowers with predominant green inner segments Blooms 6 weeks earlier than the common snowdrop. Woodland plant. Performs best in the shade and in rich well-drained soil. Height: 12” USDA Hardiness Zones 3 to 8

Jasminum nudiflorum…..Winter Jasmine

Winter Jasmine is known to be one of the earliest blooming plants in the landscape. The 1″-wide yellow blooms open in January to March prior to the leaves but, unlike most jasmines, are not fragrant. The trailing branches root where they contact bare soil. Fill in areas if you like or support with a trellis. Plant in full sun to partial sun, in well-drained soils. Height 15’ USDA Hardiness Zones 6 to 10

Hamamelis mollis……Chinese Witch hazel

This ornamental deciduous shrub is known for its strongly scented flowers. It flowers in late January or early February and produces spider-like flowers which are long lasting. Plant in full sun to partial shade in moist fertile acidic soils. Height 10-12 feet (slow growing) USDA Hardiness Zones 5 to 8

 

 

Lonopsidium acaule…False diamond flower (aka: violet cress)

Violet cress is a low growing annual plant with tiny pale lilac flowers appearing in early spring smelling like honey. It is Ideal for rock walls and edging plants. They need partial to deep shade with moist well-drained soil. Violet cress has naturalized in California through self-seeding, but they are not native to the U.S.; the USDA considers it an escaped weed!
Height 3-4” USDA Hardiness Zone: 3 to 9

Eranthis….….Winter aconite

Winter aconite i s a member of the butter-cup family. All parts of this plant are poisonous, although its acrid taste m akes poisoning a low risk. Winter aconite blooms in late January or early February and blankets the ground with small, sunny, yellow blooms. Plant in well drained hum us-rich soil. This plant dies down completely after spring. It’s a good companion with snowdrops. Self seeds.
Height 8” USDA Hardiness Zone: 4 to 9
Eranthis – “A butter cup field in January. That is what the aconite will do for you…”, Beverley Nichols, Down the Garden Path.

Chimonanthus fragans……Wintersweet

Hard to find old-fashioned deciduous shrub, but worth the search. The buds form in the fall and grow larger with each warm winter’s day. It can take three to five years to reach bloom stage, but it’s attractive in all seasons with tapered leaves on arching branches, which turn clear yellow in the fall. Easy to grow. Plant in sun or part shade and where you can walk by and enjoy its perfume.
Height 8-10’ USDA Hardiness Zone: 7 to 9

“If they (Wintersweet) are cut in bud, they lasted (in a vase), with the discreet assistance of a tablet of aspirin,…. nearly a month. Their perfume was as sweet and delicate as anything you could desire.” Beverley Nichols, Down the Garden Path.

 

Crocus imperati…..Early crocus

Lilac flowers with outside of outer petals buff, marked with dark purple. A reliable bloomer. Blooms in December or January. Plant in well drained soil, in the sun. Height 6” USDA Hardiness zone: 3 to 8

 

Crocus sieberis…….Snow crocus

A small, very early spring blooming, crocus which naturalizes easily and is ideal for rock gardens, under trees and shrubs, borders, and large drifts. Colors vary from white, blue, mauve, purple, having areas of white, yellow, or orange in the throat. Plant in well drained soil.
Height 3-4” USDA Hardiness Zone: 3 to 8

Corylopsis Spicata……Spike Winterhazel

Deciduous shrub with open, bushy, upright, spreading, picturesque branches. Flowers are clear yellow in 1 to 2″ drooping clusters blooms in later winter and early spring. Fragrant. New leaf growth is dark purple and matures to deep blue-green. Plant in sun to partial shade. Do not over water. Height 6-8’ USDA Hardiness Zone: 6 to 8

 

 

Daphne meszerum – February Daphne

February Daphne is a deciduous to semi-evergreen shrub. Vibrant lilac-purple, neon pink or white flowers bloom on naked twigs in February and have a deliciously potent fragrance . It has thin soft green leaves in the summer followed by brilliant scarlet berries in September. Unlike other Daphnes, D. meszerum likes more sun and summer irrigation. Plant in well drained porous soil. Height 3-4’ USDA Hardiness Zone:5 to 8

“…learn this by heart: “The Daphne mezereum loves it roots in the shade and its head in the sun….” Beverley Nichols, Down the Garden Path

Daphne odora- Winter Daphne

Winter Daphne is a handsome evergreen plant with powerful fragrant flowers. Pink to deep red flowers displayed in nosegay-clusters at the end of its branches. Blooms from February through April. Daphne odora needs air around its roots so plant in humus-rich semi-porous soil. Prefers mid-afternoon shade. Height: 4’ USDA Hardiness Zone: 4 to 10, 12, 14-24

Lonicera fragrantissima …..Winter Honeysuckle

Winter Honeysuckle is a deciduous shrub, in the nor thern states. Its creamy-white flowers are borne on naked twigs in February and produce a sweet lemony fragrance. Budded branches will bloom in doors for winter bouquets. Height 8-10’ USDA Hardiness Zone: 5 to 9

Please note: The U.S. Forrest Service listed Lonicera fragrantissima as a persistent invasive threat to native habitats, especially in the southern states region.

Sternbergia lutea…Winter Daffodil (aka: Fall daffodil)

Winter daffodils have vibrant yellow, crocus-like blooms. They require a sunny location with well-drained, humus-rich soil and wind protection. The bulb can develop bulb rot if planted in too moist of an area. It produces crocus-like leaves after flowering, which lasts through the winter. These bulbs are touted as hardy bulbs but they are native to warmer winter regions so they are really semi-hardy because they can be injured at temperatures below 28°F. Need winter protection: plant in pots then move indoors, or into a greenhouse, for the winter. Note: Do not plant in the drip line of trees. Height 6-10” USDA Hardiness Zone:5 to 9

Sternbergia lutea – “…though its petals may be frozen with impunity, and though it will stand any amount of wind…it hates being dribbled upon.” Beverley Nichols, Down the Garden Path

Petasites fragrans….Winter Heliotrope

Winter heliotrope has lilac to pink flowers that smells like vanilla. It’s a garden-escaped wildflower due to seed propagation, difficult to control spreading. It flowers November through to February. Grows in warm climates. Height 6-8” USDA Hardiness Zone: 9 to 10

Iris stylosa …Winter Iris

This little beardless dwarf iris is sometimes called the Algerian iris. It’s lavender-blue flowers has a lemony-vanilla aroma. Planting them against a sunny wall will lessen their exposure to winter cold and encourage early blooming. Plant in well drained soil and do not water in the summer when dormant. Height 6-9” USDA Hardiness Zone: 4 to 9

*Another late-winter Iris: Iris reticulate: Blooms in mid-February in shades of blue & purple. Height 3”-6”

Forsythia intermedia…..Forsythia

A deciduous shrub with upright spreading branches. Vigorous grower. Blooms in early March though April with very showy yellow blooms lasting 2 to 3 weeks. Plant in full sun to partial shade. It is very adaptable to poor soils, but prefers moist, well-drained soils. Plant in full sun. Height 8-10’ USDA Hardiness Zone: 4 to 8

 

Erica carnea…..Winter Heath

A dwarf evergreen shrub native to the European Alps which persist even under the snow. It often blooms at Christmas (“Winter Beauty”). Flowers are borne individually on the stem in masses of bell-shaped blossoms. Colors range from creamy white, rich pink, to deep ruby red (“ Ruby Glow”). Plant in well drained humus-rich soil. It needs partial shade in hotter areas. Spreads to 3 feet, so give it room. Prune yearly to prevent “legginess”.
Height 12-18” USDA Hardiness Zone: 2 to 10

“They are adorable, these clumps of winter heather. Actually they seem to welcome the snow, for it enhances their sweet complexions.” Beverley Nichols, Down the Garden Path

By: Carlotta Lucas

Pinky Winky Hydrangea

Posted on by

A very unique new hardy Hydrangea with massive two-toned, white and pink flowers. strong upright red stems hold the large blooms up so you never get the dropping look you get from Pee Gee Hydrangea.

The flowers heads continue to grow throughout the season and as the older flowers turn dark pink the new flowers continue to emerge white. The effect is stunning.

Winner of the 2008 Royal Horticulture Society Award of Garden Merit – AGM Three star – Excellent Rating