Lost in the sea of more popular and showy spring-flowering landscape shrubs like azalea, spirea, and the like, is an underused, exceedingly tough, and currently flowering Florida native shrub that is deserving of a spot in your landscape, Walter’s Viburnum (Viburnum obovatum).
Species Walter’s Viburnum (Viburnum obovatum). Photo Credit: UF/IFAS.
Walter’s Viburnum, named for English-born botanist turned South Carolina farmer Thomas Walter, who first described the species in the late 1700’s, is a spring-flowering mostly evergreen shrub/small tree native to the Southeastern United States. In its native environment around hammocks, swamp edges, and near-river forests beneath the understory of canopy trees, Walter’s specimens often grow to around 15’ in height, live for more than 50 years, and spread slowly into loose thickets from their extensive underground root system. After covering themselves in clusters of small, showy, pollinator-attracting white flowers in spring, Walter’s produces small reddish-black fruit that are magnets for birds and other small wildlife in summer.
Though this tough, low-maintenance nature and gorgeous pure white March flower display should have seemingly enabled Walter’s to be a standout in the landscape, Walter’s Viburnum languished in popularity for many years as it didn’t fit into most landscapes in its wild form. Not too many folks in modern landscape situations are looking for a thicket forming, unkempt-looking tree! However, with increased breeding efforts aimed at selecting superior dwarf varieties and the rise in interest in using low-maintenance native plants, Walter’s has rapidly gained market share on traditional flowering shrubs in nurseries and yards in across Florida.
These newer dwarf varieties of Walter’s, including standouts like ‘Mrs. Schiller’s Delight’ and my personal favorite ‘Whorled Class’, only grow 3-4’ in height and make an excellent replacement for more commonly planted small foundation shrubs. Why plant a disease-prone Boxwood when you can have a disease-resistant native dwarf Walter’s Viburnum? Why allow your landscape to be saddled with drab Dwarf Yaupon Holly when you could get the same basic effect AND an awesome flower show by planting a dwarf Walter’s? Tired of having to constantly prune those Loropetalum or Azaleas to keep them from hiding the house? I think you know the answer by now; plant a slow-growing dwarf Walter’s!
‘Whorled Class’ dwarf Walter’s Viburnum in a Calhoun County, FL landscape. Photo Credit: Daniel Leonard, University of Florida/IFAS Extension – Calhoun County.
Both the “wild-type” Walter’s Viburnum and the newer dwarf cultivars are about as low maintenance landscape shrubs as one could want. Though Walter’s normally occurs in shaded understory situations with moist, acidic soils in the wild, it is very adaptable to all manner of landscape situations. The species takes full sun extremely well but will also thrive with shade. It will tolerate very moist soil but, once established, is drought tolerant. I fertilize my Walter’s plants each spring with a general purpose, balanced garden fertilizer to boost growth, but there are many plantings of the species that get by without supplemental fertilizer. Finally, due to the dwarfing nature of the previously mentioned Walter’s cultivars, constant shearing won’t be necessary to maintain a pleasing shape, but they do respond well to pruning when a haircut is needed!
If you’ve been looking to include something a little bit different from the standard spring flowering fare in your landscape but also require your plants to be tough adaptable, try Walter’s Viburnum, especially the cultivars ‘Whorled Class’ or ‘Mrs. Schiller’s Delight’. They’ll be attractive, low-maintenance additions to nearly any Panhandle landscape for years to come! For more information about Walter’s Viburnum or any other horticultural or agricultural topic, contact your local UF/IFAS County Extension office. Happy gardening!
Fall is the season for leaf color changes on many plants, but we are often concerned when we see evergreen plants with brown leaves. Learn what is normal browning for evergreens and when to seek more help from UF IFAS Extension Escambia County.
Looking to add something to brighten your landscape this autumn? Firespike (Odontonema strictum) is a prolific fall bloomer with red tubular flowers that are very popular with hummingbirds and butterflies. Its glossy dark green leaves make an attractive large plant that will grow quite well in dense shade to partial sunlight.
In frost-free areas firespike grows as an evergreen semi-woody shrub, spreads by underground sprouts and enlarging to form a thicket. In zones 8 and 9 it usually dies back to the ground in winter and re-sprouts in spring, producing strikingly beautiful 9-12 inch panicles of crimson flowers beginning at the end of summer and lasting into the winter each year.
Firespike is native to open, semi-forested areas of Central America. It has escaped cultivation and become established in disturbed hammocks throughout peninsular Florida, but hasn’t presented an invasive problem. Here in the panhandle, firespike will remain a tender perennial for most locations. It can be grown on a wide range of moderately fertile, sandy soils and is quite drought tolerant. Firespike may be best utilized in the landscape in a mass planting. Plants can be spaced about 2 feet apart to fill in the area quickly. It is one of only a few flowering plants that give good, red color in a partially shaded site. The lovely flowers make firespike an excellent candidate for the cutting garden and is a “must-have” for southern butterfly and hummingbird gardens. Additional plants can be propagated from firespike by division or cuttings. However, white-tailed deer love firespike too, and will eat the leaves, so be prepared to fence it off from “Bambi”.
The showy chaste tree makes an attractive specimen as the centerpiece of your landscape bed or in a large container on the deck. Much more of them are being seen since the Florida Department of Transportation has recognized the tree as a desirable median planting. Easy-to-grow, drought resistant, and attractive to butterflies and bees, Vitex agnus-castus is a multi-stemmed small tree with fragrant, upwardly-pointing lavender blooms and gray-green foliage. The chaste tree’s palmately divided leaves resemble those of the marijuana (Cannabis sativa) plant; its flowers can be mistaken for butterfly bush (Buddleia sp.); and the dry, darkened drupes can be used for seasoning, similar to black pepper, making it a conversation piece for those unfamiliar with the tree.
Vitex , with its sage-scented leaves that were once believed to have a sedative effect, has the common name “Chastetree” since Athenian women used the leaves in their beds to keep themselves chaste during the feasts of Ceres, a Roman festival held on April 12. In modern times, the tree is more often planted where beekeepers visit in order to promote excellent honey production or simply included in the landscape for the enjoyment of its showy, summer display of violet panicles.
Chaste tree is native to woodlands and dry areas of southern Europe and western Asia. It will thrive in almost any soil that has good drainage, prefers full sun or light shade, and can even tolerate moderate salt air. Vitex is a sprawling plant that grows 10-20 feet high and wide, that looks best unpruned. If pruning is desired to control the size, it should be done in the winter, since it is a deciduous tree and the blooms form on new wood. The chaste tree can take care of itself, but can be pushed to faster growth with light applications of fertilizer in spring and early summer and by mulching around the plant. There are no pests of major concern associated with this species, but, root rot can cause decline in soils that are kept too moist.
Article written by Dr. Gary Knox, North Florida Research & Extension Center – Quincy, FL.
‘Gumpo Pink’ flowers are 3 inches in diameter and are pink with purplish pink dots and occasional white blotches on petals.
Background
In the times before re-blooming azaleas like Encore®, Bloom-A-Thon® and others, Satsuki azaleas were valued for late flowering that extended the azalea “bloom season”. Even with modern re-blooming azaleas, Satsuki azaleas still are appreciated as refined evergreen shrubs for the sophisticated garden or discerning plant collector.
“Satsuki” means “Fifth Month” in Japanese, corresponding to their flowering time in much of Japan. These azaleas were developed hundreds of years ago from their native Rhododendron indicum and R. eriocarpum. The Japanese selected cultivars more for their form and foliage than for flowering. These beloved plants were used in gardens as sheared boxwood-like hedges or pruned into rounded mounds that might resemble rocks or boulders in classical Japanese gardens. Their size and form also made them well adapted for training as bonsai. Most of the Satsuki azaleas in America were introduced in the 1930s by USDA.
Description
Satsuki azaleas are small evergreen shrubs that flower in April and May in north Florida, long after most older type azaleas have finished. Satsuki azaleas also are known for producing large, mostly single flowers up to 5 inches in diameter in colors of white, pink, red, reddish orange and purple. Often the flowers will include stripes, edging, blotches, spots or flecks of contrasting colors (Sometimes all on the same plant!) with more than 20 different color patterns recorded.
Satsuki azaleas have an elegant subtle charm, quite unlike the flashy, over-the-top, heavy blooming all-at-once Southern Indica azaleas like ‘Formosa’ and ‘George L. Taber’. Typically, Satsuki azaleas display a few large blooms at a time, allowing one to better appreciate their size and color patterns as contrasted against their fine-textured, dark green leaves. To make up for a less boisterous display, Satsuki azaleas flower over a longer timeframe, averaging about 8 weeks, with some flowering an amazing 14 weeks. In another contrast, most Satsuki azaleas grow smaller in size, in my experience reaching about 3 feet tall and wide in a five-year timeframe. The rounded to lance-shaped leaves of Satsuki azaleas also are demure, ranging in length from just ½ inch to no more than 2 inches.
Culture
Satsuki azaleas enjoy the same conditions as most other azaleas: light shade and moist, rich, well-drained soil. Mulch regularly to maintain organic matter and help hold moisture. Fertilize lightly and keep the roots evenly moist. Minimal to no pruning is required. Satsuki azaleas also are well adapted to container culture. Their small size and fine textured leaves make these a favorite for bonsai enthusiasts since their small leaves, branching habit and mounded form naturally make them look like miniature mature “trees”.
Sources and Cultivars
Look for Satsuki azaleas in spring at garden centers or year-round at online nurseries. There are hundreds of cultivars but some popular types to look for include:
Gumpo Pink – 3-in. diameter light pink flowers with purplish pink dots and occasional white blotches
Gumpo White – 3-in. diameter white flowers with occasional pink flakes and light green blotches
Gyokushin – 3-in. diameter flowers are predominantly white but with light to dark pink dots and blotches
Higasa – flowers are 4 to 5 inches in diameter and are purplish pink with purple blotches
Shugetsu – also called ‘Autumn Moon’, 3-in. diameter flowers are white with a broad, bright purplish-red border
Tama No Hada – flowers are 4 to 5 inches in diameter and are white to pink with deep pink stripes; usually flowers in fall as well as spring
Wakaebisu – 2.5-in. diameter flowers are “double” (hose-in-hose) and are salmon pink with deep pink dots and blotches; this also flowers in fall as well as spring
References:
Chappell, M. G.M. Weaver, B. Jernigan, and M. McCorkle. 2018. Container trial of 150 azalea (Rhododendron spp.) cultivars to assess insect tolerance and bloom characteristics in a production environment. HortScience 53(9-S): S465.
‘Gumpo Pink’ flowers are 3 inches in diameter and are pink with purplish pink dots and occasional white blotches on petals.
‘Gyokushin’ flowers are white with occasional pink flecks and light green blotches.
‘Shugetsu’ has 3-inch flowers that have bright purplish-red border on edges of petals.
Galle, Fred C. Azaleas. 1985. Timber Press, Portland, Oregon. 486 pp.
The last several weeks have brought consistently cool weather to the Panhandle, with a few downright cold nights dipping well below freezing. Though winter isn’t officially here, that won’t happen until December 21st, grass mowing season is definitely over and, if you’re like me and didn’t cover your raised bed garden on those nippy nights, vegetable growing has also slowed significantly. So, what are us horticulturally minded folks with cold-weather cabin fever to do? It’s time to take advantage of sweat-free temperatures, break out the shovels and pruners, and get to work in the landscape!
Master Gardeners demonstrate correct tree planting techniques.
The months of December through February are ideal times for planting new trees and shrubs. The reasons for this are simple. Days are short, rain tends to be plentiful, temperatures are cool, and plants are mostly dormant. While newly installed plants need water to become established regardless of when they are planted, demand for supplemental irrigation is significantly less in winter (one of our rainiest seasons) and the chances of a new planting dying from thirst is slim relative to warmer months. Also, planting in winter gives trees and shrubs several months of above ground dormancy to focus their resources below ground, recover from the shock of transitioning from a nursery container into your native soil, and produce valuable roots that will help it get through its first summer. Think about it. Would it be easier for you to start and finish a major outdoor project in July with one bottle of water to drink or in December with an ice chest full? Plants prefer the same!
Not only is winter perfect for planting, tis the season for pruning many species too, deciduous trees (those that lose their leaves in the fall) in particular! The first reason to prune these species in the winter is to give the plants several months to begin healing before growth resumes in spring and insect and disease pressure ramps up again. Many serious pests and diseases of trees are most active during warm, wet weather and all of them have easier access to attack trees through open wounds. Prune in winter to help avoid unwanted pest and disease infestations. Also, dormancy has conveniently knocked the leaves off deciduous species’ branches, allowing us a clear view of the tree’s crown and giving us the ability to make clear, clean, strategic pruning cuts. Proper pruning can help maintain a strong central leader that produces a stately, straight tree and remove dead and diseased branches that could cause problems in the future.
While planting in the winter is always ideal and we just outlined several reasons pruning now can be good, not all plants should be pruned when dormant. For instance, old-fashioned hydrangeas and azaleas that produce blooms from the previous season’s growth. Pruning these in the winter removes all the flower buds that would have bloomed the next summer and what’s the point of an azalea or hydrangea that doesn’t bloom? Also, many small trees and shrubs, like Crape Myrtle and Vitex, may never need pruning if you site them where they will have room to mature without encroaching on other plants or structures.
If you have any questions about planting trees and shrubs, what, when, and how to prune, or any other horticultural topic, please contact your local UF/IFAS Extension Office! Enjoy the weather and happy gardening!
