Few trees have as good a pedigree as this magnolia. Plantsman Don Shadow of Shadow Nursery in Tennessee selected this plant from a large batch of seedlings he grew out from the late Dr. J.C. MacDaniel, a prolific plant breeder from the University of Illinois. Magnolia virginiana var. australis ‘Green Shadow’ makes a neatly oval outlined tree to about 30′ tall by about half as wide. The clean, green foliage with silvery backs is highlighted by virginal white flowers to 3″ across over an extended period from spring well into summer. The heaviest flowering is early in the season but sporadic flowers appear for up to 4 months. The sweet, lemon scented flowers are followed by curious bulbous reddish fruit which can actually be quite showy. This is one of the fastest growing of the southern (var. australis) types of sweetbay magnolia we’ve grown here at the JC Raulston Arboretum. This tree is reliably evergreen through USDA hardiness zone 7 but can be grown in much colder climates. Magnolia virginiana grows naturally in swampy soils and while perfectly happy in drier spots, it also tolerates permanently and seasonally wet locations and makes a great specimen in rain gardens.
Flowering weigela is an old-fashioned shrub that can be found growing in many mature shrub borders and gardens. There is nothing old-fashioned about this oddity though. Creamy white margins on each leaf are only the beginning. The foliage is curiously puckered and contorted with the central green portion growing larger than the constricting white margin. The overall effect is actually quite nice with a mound of foliage that sparkles in the sun and adds quite a bit of texture to the garden. Light pink, tubular spring flowers fade to white for a two-toned flower show. The puckered foliage seems to keep this plant somewhat more compact so expect Weigela florida ‘Caricature’ to grow to about 5′ over time, perhaps larger in rich soils. Prune immediately after flowering to control height if desired and grow in full sun to very light shade for best flowering.
The JC Raulston Arboretum is a living laboratory in the Horticultural Science Department at NC State University. Students and faculty from all disciplines use the collections for education and research. We have Forestry researchers working with our firs (Abies) breeding heat and root rot resistant Christmas trees, Plant Biology research on dogwoods (Cornus) and other genera, entomologists sampling insects, weed science (looking in vain for weeds I hope!), and of course plenty of horticulture students out for plant ID, propagation, design, and landscape maintenance classes.
This summer, lecturer Lee Ivy is teaching a new course called Hands-On Horticulture where students have the opportunity to gain experience in a variety of areas from hardscape construction and installation to tree pruning. Today we caught the class up in a couple of oak trees at the JCRA getting experience in climbing and tree work. They were looking pretty good by the end of the lab. We’ve been training students to climb trees for decades here at the JCRA, in fact, JCRA director Ted Bilderback taught tree maintenance classes back in the early 80′s.
Bigleaf hydrangeas are mainstays of the shade garden where the large, glossy green foliage provides a lush look and the showy flower heads light up the garden. This recent introduction from Ball Horticultural Co. called Hydrangea macrophylla ‘Perfection’ is proving to be a show-stopper in the landscape. Large flower heads composed of dozens of fully double florets with pointed petals are held on sturdy stems. It is one of the first double flowered forms that is also a pretty good re-bloomer for us with waves of flowers occurring over the summer if old heads are removed. It seems to want to be pink and I haven’t seen a true blue, even in very acid soils it tends to be a purplish hue. This is a relatively compact plant to 3′ tall and a bit wider, perhaps as much as 5′ wide over time. Grow in part shade in a moist, well-drained soil.
Sabal palmetto ranges from Florida to southeastern North Carolina. It is the main trunked palm of the southeast US and the state tree of South Carolina. This form is from the northernmost native stand of palmettos on Bald Head Island off the coast of Wilmington, NC. It has proven to be one of the hardiest selections available, surviving to 6 F (-14 C) once established with no problem. It can grow to 35′-40′ tall over time with a stout trunk and folded (costapalmate) fronds. This plant enjoys a sunny, well-drained spot. Transplanting palms can be confusing with some surviving easilyand others dying immediately. Sabal palmetto and some other palms will only transplant well as field or garden grown plants if they are mature – generally about 10′ of clear trunk with fronds cut off for Sabal palmetto. Palmetto roots die back when cut and will not grow new roots unless the plant is mature. Large transplanted specimens should be kept well hydrated and fronds trimmed back until new roots grow. For most gardeners, small (3g for best survivability) container grown plants are probably the best option. Make sure to avoid cultivating around the base of palmettos too much as this will cut the roots.
The JC Raulston Arboretum holds a significant collection of Aucuba, over 70 taxa at this point and growing steadily. This form, ‘Hosoba Hoshifu’ is quickly becoming a favorite. Long, narrow leaves are heavily serrated and covered in bright gold spots. The lanceolate foliage gives a distinctive look to this speckled aucuba. Spikes of small maroon flowers give rise to large, bright red fruits if there are male forms around to pollinate it. ‘Hosoba Hoshifu’ is a slightly more compact form but will slowly grow to near 6′ over time. Aucuba are great plants for growing in dry shade where they will tolerate the difficult conditions well once established and the variegation will brighten the gloom.
Yesterday, we had a special visit from the Raleigh Trolley. It brought 19 campers from the City of Raleigh’s Parks and Recreation, Camp Raleigh on the Go! The campers, all ages 9-12 years old, learned about the history of the JC Raulston Arboretum, smelled chocolate flowers (Berlandiera lyrata), and took pictures with the dragon on the Ellipse. Before hopping back on the Raleigh Trolley to their next destination, they engaged their senses in the Paradise Garden and enjoyed the shade under the majestic ‘Fantasy’ crape myrtle.