Oyama or Siebold Magnolia

Oyama sieboldii

Oyama magnolia (Magnolia sieboldii) is a 10-15 feet tall (and equal spread) deciduous tree or large shrub from eastern Asia. It prefers to grow in partial sunlight and in moist, well drained loamy soil (USDA zones 6 -8). Why are not more gardeners are not growing this small tree/shrub magnolia. Spring bloom is in May, avoiding the threat of frost injuring the flower buds of this later blooming magnolia.

White nodding egg-shaped flower buds appear in late June, and blooms appear intermittently thru most of the summer. The 1-3 inch wide saucer shaped flowers are white, centered by crimson stamens within. Oyama begins to flower at an early age.

The 3-6 inch long medium green foliage is first to appear in April, coated with a silvery pubescence. Leaves turn pale yellow before abscising in mid-autumn. Small pink fruits appear in late summer, and split open to reveal orange-red seeds in late September. Branch bark wood is light gray.

Feed magnolias with a slow release fertilizer in early spring. They benefit from annual mulching.  Pruning shrub to desired shape and size, and to remove dead or broken branches.

Oyama magnolia is an excellent pick for a small garden. It is available from  a few on-line specialty nurseries.

Seedless (Sterile) Blooming Rose Of Sharon Shrubs

'Lavender Chiffon' althea

Rose of Sharon, aka shrub althea, (Hibiscus syriacus) is a woody hibiscus shrub that is hardy in temperate northern areas of the U.S. (USDA hardiness zones 5-9). This summer flowering shrub is exceptionally easy to grow. 

At one time,  it was a great pass-along shrub that fell out of favor. However, old fashioned varieties frequently reseeded around the garden. New cultivars strut variegated foliage, double flowers, and infertile (sterile) blooms that produce little or no seed. They are available in a wide range of flower colors including pink, purple, blue, white, and almost red. 

Blooms may be single, semi-double, and double and range in size from 2-5 inches across. They grow in average to good garden soils with moderate drainage. For maximum flowering, site plants where they receive 6 or more hours of direct sun and feed annually with a slow-release fertilizer such as Osmocote™ or Nutricote™. Blooms attract numerous bees and butterflies. Japanese beetles may damage the flowers for a few weeks in early summer, but shrubs rapidly recover.

After their first year, Rose of Sharons are highly drought tolerant. Shrubs respond well to annual pruning and to severe “rejuvenating” by pruning to a few inches above the ground.

Some gardeners opt to grow them as perennials by cutting the plant back every year or two. In late spring the “shortened” plant(s) emerge as multi-stems, grow a 2-3 feet tall, and flower.

Alternative technique: thin out emerging growth to 1, 3 or 5 main shoots to train into a small patio tree.

Utilize Rose of Sharon as a specimen shrub or small tree, as a shrub border, or set into a large container. Best of the sterile forms of Rose of Sharon (althea):

Chiffon® series feature anemone-like double blooms for low seed set and long-blooming; color choices: Lavender (purple), Blue, and White; 8-12 feet x 6-10 feet wide.

Sugar Tip® - pure pink double blooms (no seed) and variegated semi-double creamy-white blooms/ bluish-green foliage; 8-12 feet x 6-8 feet.

Purple Pillar® - slender columnar growth habit (16 feet tall x 3 feet wide), 4-inch vibrant purple single to semi-double flowers with red centers; ideal fit for small urban gardens.

Venus® Is A Unique Flowering Dogwood

7" Bracts of Venus® dogwood (C. kousa x C. nuttali)

Spring flowering dogwoods (Cornus spp.) are back in vogue again (USDA hardiness zones 6-9). A better understanding about growing dogwoods coupled with improved resistant disease varieties have seen the return of dogwoods to landscapes again.

If you want to plant a variety with the largest flowers, no question it is Venus®. This hybrid dogwood (Cornus kousa 'Chinensis' x Cornus nuttalii 'Goldspot' x Cornus kousa 'Rosea')  was developed at Rutgers University by Dr. Elwin R. Orton (now retired). The tree's large bracted blooms measure 6 - 7 inches across in April and May. 

Venus dogwood grows vigorously, 15-20 feet tall (slightly greater in spread). It is a small deciduous tree forms a dense, low-branched, spreading habit.

Venus is resistant to anthracnose and powdery mildew diseases. It has clean dark green foliage and large flowers. Red dogwood fruits attract lots of birds in early fall. Fall leaf color is red to orange.

This dogwood grows in average, medium moisture, well-drained soils in full sun to partial shade. In southeastern U.S., morning sunlight and afternoon shade is best. Summer leaf scorch may indicate too much direct sunlight and/or exposure to hot, windy or dry soil conditions. The tree benefits by applying 2-3 inches of a wood-based or needle mulch that keeps tree roots cool and moist. For the first 2-3 summers, a young dogwood should be irrigated during dry periods.

Venus dogwood, when properly sited and cared for, have few disease and insect problems. Stressed trees become vulnerable to stem cankers and insect borers. Deer are usually not troublesome.

Dogwoods are planted on urban and suburban lawns and around patio areas. Venus dogwood needs to be special ordered from garden centers or purchase from e-commerce nursery sources.

Korean Sweetheart Tree

Bright Red Fruits of Sweetheart Tree

The late Dr. J. C. Raulston, N.C. State University horticulture professor emeritus, discovered Korean sweetheart tree in 1985 on the Korean Peninsula while participating in a U.S. National Arboretum collection expedition. 

Dr. Raulston brought seeds back to the N.C. State Arboretum for assessment and evaluation. The common name "sweetheart tree" was coined by Tennessee nurseryman Mr. Don Shadow.

The tree prefers a sandy or medium loamy soil and full sun to partial shade. Once established the tree tolerates brief dry periods lasting 4-5 weeks, and is at its best in soils with consistent and even moisture. Provide supplemental irrigation in regions where summers are exceptionally hot and dry.

Opposite pinnately compound leaves measure 6-10 inches long. The fruits are major asset for this small growing tree/large tree. In late summer showy clusters of heart-shaped fruits ripen from green to pink to red. In early to mid-October the fruit capsules split open to reveal a tiny, shiny, black seed.The grayish colored bark has white striations which adds some winter interest.

No serious disease and insect problems trouble this small 25-30 feet tall tree. Availability is primarily from on-line plant nurseries

Select These Ornamental Crabapples

For those gardeners tired of Bradford pear problems, go shopping for ornamental crabapples (Malus spp.). Selected cultivars mature into lovely small spring flowering trees. Most fit under utility lines. Be careful which cultivars you choose.

Worldwide, there are over 400 cultivars of crabapples in nursery commerce. Most are susceptibility to one or more serious foliar diseases that include fire blight, cedar apple rust, apple scab, powdery mildew and frog-eye.  All 19 listed below are rated with above average disease resistance.

Ornamental crabapple fruits add ornamental beauty in fall and winter seasons. Fruit size is small, less than 5/8 inches in diameter. An extra bonus is that small birds are attracted to the fruits from late fall thru winter.  There is no mess on lawns, walkways or cars.

Consult experts at your state's land grant university for an updated listing which may also additional cultivars. Varieties 'Prairifire', 'Sugartyme', Japanese flowering crabapple (M. floribunda) and M. x sargentii are popular at garden centers nationwide.

Here is your shopping list of 18 of the best.

Adams - 20 x 20ft. (magenta flowers & red fruit)                            

Adirondack - 18 x 10 ft. (white flowers & orange-red fruit)

Cardinal® - 16 x 22 ft. (pink-red flowers & red fruit)

Centurion® - 20 x 15 ft. (pink flowers & red fruit)

David - 12 x 12 ft. (white flowers & red fruit)

Donald Wyman - 20 x 20 ft. (white flowers & red fruit)

Doubloons - 18 x 16 ft. (double white flowers & yellow fruit

Firebird® - 8 x 10 ft. (magenta flowers & red fruit)

Japanese flowering crabapple (M. floribunda) - 20 x 20 ft. (light pink flowers & dark red fruit)

Louisa - weeping 10 x 12 ft. (pink flowers & yellow fruit)

Pink Princess™- 8 x 12 ft. (rose pink flowers & red fruit)

Prairifire - 20 x 20 ft. (red-purple flowers & dark red fruit)

Purple Prince® -   20 x 20 ft. (rose red flowers & maroon fruit)

Royal Raindrops® - 20 x 15 ft. (pink red flowers & red fruit)

sargentii - short spreader 8 x 14 ft. (white flowers & red fruit)

sargentii ‘Tina’ - dwarf 5 x 6 ft. (white flowers & red fruit)

Sugartyme® - 18 x 15 ft. (white flowers & red fruit)

White Cascade® - weeping 15 x 15 ft. (white flowers & lime-yellow fruit)

zumi ‘Calocarpa’ -  20 x 24 ft. (white flowers & red fruit)

* Thanks to J. Frank Schmidt & Sons Co., Boring, OR for their cultivar height and width data and foliar disease ratings.