Sunday, April 29, 2012

Versatile Viburnums

I've been a fan of viburnums for some years now – they have beautiful flowers, good looking foliage and great fall color.  They also have berries that the birds eat.  On top of good looks, they are truly some of the most versatile shrubs that I know.   I like to say there is a native viburnum to suit every situation you have: sun, shade, wet, or dry.  Yes, the blooms all look very similar but there is a difference in foliage shape, berries, size and habit.

Viburnum acerifolium

It would be hard to pick a favorite but Viburnum acerifolium would certainly be on the short list. Commonly known as the mapleleaf viburnum because of the leaf shape, the first blog entry that I ever wrote was about this plant, so I’ll be brief here (and you can read more about it there).  The range of this plant in Georgia is primarily in the more northern regions, but it does extend into the upper coastal plain.  Found in the understory of mesic woods (moderately moist), it is tolerant of drier and shadier conditions than many shrubs.  It tends to sucker a bit, creating a loose colony in ideal conditions.  The fall color is superb, and the berries are dark blue and large.

Viburnum dentatum 'Blue Muffin'

The viburnums known as “arrowwoods” (for their straight limbs) include Viburnum dentatum  (southern arrowwood) and Viburnum recognitum (northern arrowwood).  More unusual are two others:  bracted arrowwood, Viburnum bracteatum, and downy arrowwood, Viburnum rafinesqueanum, both of which are occasionally found in the Piedmont.  V. dentatum is found throughout Georgia from the northernmost counties into the coastal plain, including a few of the maritime counties.  Growing conditions vary from upland sites to swampy tracts.  A few cultivars are now available in nurseries: ‘Blue Muffin’ is one that I have and I hope they didn’t mean for “muffin” to indicate a dwarf form because it is not.  According to Michael Dirr, ‘Little Joe’ is a true dwarf in his Georgia garden.  Berries are smallish and medium blue in color.

Viburnum nudum  var. cassinoides

Viburnum nudum  var. cassinoides

Another wet tolerant viburnum is possumhaw or Viburnum nudum,  a species which now includes Viburnum nudum  var. cassinoides .  Between the two of them, this species can be found in practically the entire state, including the maritime areas.  While there are many similarities between the two, notably their bare twigs and their fruit, I find that the foliage is quite different.  Smooth, dull green leaves with a faint white stripe down the center are characteristic of var. cassinoides while nudum has shiny, deep green leaves that have no stripe and are faintly “quilted” in appearance.  Both have excellent fall color and pinkish berries that are colorful enough to resemble flowers from a distance.  In swampy conditions, suckering is part of the habit. Several cultivars have been developed, and one of the best known is 'Winterthur'.

Viburnum obovatum
One viburnum that has been getting more use in the garden is the small leaf viburnum, Viburnum obovatum.  A favorite cultivar in the trade is ‘Reifler’s Dwarf’ which offers compact growth, shiny green leaves and dozens of flowers when grown in full sun.  For me it has been semi-evergreen, another bonus.  An even more compact form is ‘Mrs. Schiller’s Delight.’ The species is indigenous to the coastal plain but does well in Piedmont areas.

Even though viburnums are shrubs, some of them can get quite tall, and there are even two of them that can be considered as small trees.  Viburnum prunifolium is known as blackhaw viburnum and the very similar looking Viburnum rufidulum is known as rusty blackhaw.  The differences between them are slight, but noticeable if you are looking for them, especially in the winter when the rust- colored leaf buds of Viburnum rufidulum are present.  The leaves of blackhaw are rather dull and thin compared to the shiny, leathery leaves of rusty blackhaw.  Both species grow to over 20 feet at maturity.  They both make fine small trees in the garden.  The distribution of the two varies – blackhaw is more northern while rusty blackhaw is widely distributed throughout the state.

Viburnum prunifolium
Viburnum rufidulum

One viburnum that is not native to Georgia is the one known as American cranberry bush: Viburnum opulus L. var. americanum or formerly Viburnum trilobum.  I have seen this for sale in Georgia stores, but it is a plant that normally grows quite a bit north of us.

I hope that the next time you are considering a shrub for your yard that you will give viburnums a closer look. Their late spring flowers will delight you and insects alike; come fall the rich colors will delight you again.

Viburnum prunifolium
Viburnum acerifolium

Good reference: Michael Dirr’s book Viburnums, published in 2007.  While it includes non-native viburnums, the pictures of flower, fruit, foliage and habit for each species make this an excellent resource.  It is especially good for Georgia gardeners as he includes comments about ones that he has grown in Athens, GA.

Sunday, April 22, 2012

Is it a Tulip or a Tree?

The tree officially known as Liriodendron tulipifera is a tree, of course, but the tulip-shaped blossoms are a delight to those that come across them.  Since the tree can be very large, reaching well over 100 feet in ideal conditions, the blossoms that one sees up close are often those that were broken in a spring thunderstorm and found on the ground.  Such accidents allow us to appreciate the details of the beautiful flowers, including the orange markings inside them.

Liriodendron tulipifera

Common names for this tree include "tuliptree" and "tulip-poplar" and even "yellow-poplar".  This is not a true poplar tree (Populus), so the common names can be a bit confusing to some.  It is a fast growing tree in my area, usually growing straight and tall as an arrow.  Despite it's fast growth, the wood is strong.  I wish more nurseries would sell this tree to homeowners looking for fast growing shade trees. The natural range for this tree in Georgia is widespread throughout the state, from top to bottom and even out to the maritime counties.

View of flowers from the ground

It is a member of the Magnolia family (Magnoliaceae) and close examination of the buds and flowers reveal the resemblance.  There are only two individuals in the genus - our native one and one in China. Liriodendron tulipifera is considered the tallest hardwood in the eastern US, and the native range spans from Florida and Texas in the south all the way into southern New England and Canada and west to Iowa.

Lobed foliage


The tree is beneficial to wildlife in several ways.  The flowers are rich in nectar and so are an excellent food source for its pollinators, including hummingbirds.  It is the larval host plant for the Eastern Tiger Swallowtail butterfly (Papilio glaucus) and others.  In the fall, mature trees produce abundant papery seeds that are eaten by cardinals, other birds and squirrels.

Next time you're looking for a fast growing shade tree, consider Liriodendron tulipifera.

Reference: USDA Forest Service publication

Sunday, April 15, 2012

Native Fruits in Georgia

Now that the bees have pollinated my blueberries, I can see the little berries forming.  I love having fresh blueberries in June and July, and I love reminding people that they are native to Georgia.  Of course the plants we purchase for cultivation have been bred to have larger fruits, but their ancestors grew up in the South and their wild cousins still live in the woods around us.  

Vaccinium pallidum

These days more and more people are interested in growing their own food so I thought I’d mention some of the native plants that have edible fruit.  Now I’m sure that some people will say there are more edibles than I am listing.  People can eat all sorts of things!  These are the more commonly available plants that are considered “edible”.  I have personally eaten the fruit of mayapple (Podophyllum peltatum) - and it was delicious - but it’s not a plant that I think people grow as food.

Native shrubs that bear fruit in sufficient quantity include blueberry (Vaccinium), huckleberry (Gaylussacia), elderberry (Sambucus), black raspberry (Rubus occidentalis), and blackberry (Rubus allegheniensis).  Of all these, blueberry is certainly the most commonly available and can usually found at most nurseries in the springtime.

Blueberries benefit from cross-pollination from other blueberries, especially blueberries that are not identical clones.  Therefore if you are buying cultivars, look to buy at least one that is not the same.  You also want to buy plants that bloom at the same time so that cross-pollination can work.  Since most reputable nurseries know this, they will usually stock different cultivars in early, mid and late season categories.  For example, 'Climax' and 'Premier' are both early season cultivars.  An excellent publication on growing blueberries at home is available from UGA here.  I have had very good luck with mid season cultivars 'Tifblue' and others (yes, the tag fell off those "others", but they get the job done).   In the northern part of the state we grow "rabbiteye" blueberries; the UGA publication also talks about the more southern varieties.

Blueberries also turn a beautiful red color in the fall and are not bothered by deer as far as I can tell.  They do like full sun (6 or more hours) and adequate moisture, especially while the fruit is developing.

Gaylussacia baccata
Huckleberries are probably a little harder to find and have not been cultivated as much for home use.  Very similar looking to lowbush blueberries, they tend to be a colonial shrub (spreading underground) but very tolerant of drier soils.  We recently discovered black huckleberry (Gaylussacia baccata) on a site being developed and have been much charmed with the small red flowers and resin-dotted leaves.  I look forward to tasting the fruit.

Elderberry (Sambucus nigra ssp. canadensis) is a longtime favorite for pies, jams and wine as well as extracts for medicinal purposes.  The plant is large and rambunctious - give it plenty of sun and space.  If you have an area that is a little moist, so much the better.  I love to see this blooming on low roadsides, growing side by side with thorny briars, the huge flower heads supporting all manner of pollinators.  Each tiny flower in the inflorescence turns into a small purple berry.

Sambucus nigra ssp. canadensis
Elderberry fruit
Karan A. Rawlins, University of Georgia,

Subshrubs in the genus Rubus give us black raspberries and blackberries.  These will need some space as well and you must leave the old canes intact as only the second year canes (known as floricanes) will flower and bear fruit.

Trees that bear fruit include pawpaw (Asimina triloba), mayhaw hawthorn (Crataegus aestivalis), serviceberry (Amelanchier spp.), persimmon (Diospyros virginiana), plum (Prunus americana or Prunus angustifolia) , crabapple (Malus angustifolia), and mulberry (Morus rubra).

Pawpaw is a beautiful small tree with long, tropical-looking leaves, unusual maroon flowers and even more unusual fruit. It is a member of the Annonaceae family which is the "custard-apple" family.  Who even knew there was a custard-apple family?  I have heard that the fruit is delicious.  Like blueberries, the flowers benefit from cross pollination so one is encouraged to have at least two.  I have three and continue to hope that one day I'll see fruit.

Asimina triloba

Pawpaw fruit
Troy Evans, Great Smoky Mountains
National Park,

There are many species of hawthorns that are indigenous to Georgia but one in particular has been cultivated and celebrated for its fruit - the one called "mayhaw", Crataegus aestivalis.  Festivals celebrating this fruit are scattered throughout the southeast.  It is also a beautiful spring-flowering tree.  Below is a picture of Crataegus triflora to give you an idea of hawthorn blooms in general.

Mayhaw fruit
Photo by Ron Lance
Crataegus triflora

Serviceberry (Amelanchier spp.) is another tree long appreciated for it's fruit.  Several species grow throughout Georgia and are becoming more available in nurseries as people have learned to appreciate them for supporting birds.  Long before that, however, people gathered these berries for pies and fresh eating - they are good right off the tree if you can get to them before the birds.

Amelanchier arborea

Amelachier alnifolia
Mary Ellen (Mel) Harte,

I have been on a quest for native plums for some time.  I finally did get an American plum (Prunus americana) several years ago but it has not flowered yet.  I found a healthy roadside stand of Chickasaw plum (Prunus angustifolia ) this year and photographed the flowers.  I plan to return in a month or two to check for fruit to harvest either for eating or growing.

Prunus angustifolia

We don't have any native apple trees in the US but we do have Crabapple (Malus angustifolia).  Like serviceberries, plums, and hawthorns, it is a member of the Rosaceae family and the scent of the flower is unmistakeably rose-like. However, the fruit, larger than ornamental crabapples but smaller than apples, is quite tart.  You might want some sugar in that jelly.

Crabapple (not sure which one!)

Persimmon (Diospyros virginiana) is a very modest looking medium sized tree.  Blink and you will miss the tiny blooms that hang underneath the leaves.  Only female trees bear fruit so if you are purchasing one for fruit, be sure to get at least one known female.  I have the trees throughout my yard - including a recent batch of first year seedlings courtesy of some possum pooping his way through, I guess.  Native persimmons are small and orange - and quite tart; you should wait until they are naturally ready to fall before plucking them.

Persimmon fruit persists after the leaves have gone

Red mulberry (Morus rubra) is the native mulberry found throughout the state, from the Ridge and Valley to the Coastal Plain.  Unfortunately the non-native white mulberry is too.  The two look very similar, but there are some differences in the leaves.  The leaf of the non-native white mulberry is shiny on top and smooth underneath.  The native red mulberry has dull leaves that are lightly hairy underneath.  By all reports, the fruit of the red mulberry is tastier than the non-native one!

Finally you might considering growing some of our native grapes.  There are several that are indigenous to Georgia - muscadine (Vitis rotundifolia) is a familiar one.  They are sweet and tasty when plucked right from the vine, but they are often too high to reach.  Fox grape (Vitis labrusca) and summer grape (Vitis aestivalis) are two of the others in my area.

So there you have it.  Growing native plants that also provide you with a bit of food might be a fun project to explore if you are into edibles.  I have certainly enjoyed having my own blueberries.

Sunday, April 8, 2012

A Parade of Native Azaleas

The early spring native azalea bonanza just blew through my garden and it’s only the first week in April.  Yep, it was an early show this year but it was great and I took my camera out there to enjoy it often.  However, when it comes to native azaleas, the show is not over yet.  With careful planning and selection, one can have native azaleas blooming even into September in north Georgia.

Gregory Bald hybrid

Rhododendron canescens

The first one to bloom for me is the Piedmont azalea (Rhododendron canescens).  Up until this year’s early spring, bloom has always been early April.  The flowers are primarily white with a bit of pink.  The stamens are quite long, and there should be no yellow blotch on the bloom (more on that later). The flowers usually open before the leaves start to expand and continue as the leaves appear.  The fragrance of the flowers – a sweet floral scent – makes this my favorite of all the early bloomers.  The size of this species can be up to 15 feet tall, allowing it to be treated as a small tree in a specimen arrangement.

The next species to bloom often overlaps with the Piedmont azalea.  It is the Oconee azalea which is now considered Rhododendron flammeum but was once considered R. speciosum; the old name is still used by some enthusiasts.  Bloom colors are a range of yellowish-orange to orange to red, often with a yellow blotch on one petal.  The flowers may precede the leaves or occur at the same time. There is no fragrance to the flowers and, in general, it is a smaller shrub ranging up to 8 feet.

Rhododendron flammeum

In places where the two species overlap during bloom time, natural hybrids can occur.  Key indicators would be a pale color in the bloom, a yellow blotch on the petal, and a light fragrance – a little something from each parent!

Rhododendron austrinum

The Florida flame azalea, Rhododendron austrinum, would also have overlapping bloom times with the two above.  While it does grow in Georgia, it is not indigenous to north Georgia.  Color is typically yellow with a reddish tube, and the fragrance is good.  Mature height is about 8 feet.  I took this photo at a friend’s garden in Smyrna.

Next in the bloom cycle could be the Alabama azalea, Rhododendron alabamense. This one has a white colored bloom with a yellow blotch and a spicy, lemony fragrance.  I don’t have this one, but those that have it are very fond of it.  It usually blooms before the leaves and generally is a smaller shrub, up to 6 feet.  It tends to spread by stolons underground.

Rhododendron periclymenoides

Pinxterbloom azalea, Rhododendron periclymenoides, is not as common as others (and the name is really hard to say!), but it would be a good one to continue the progression of blooms.  This is from the same garden in Smyrna.  What a spectacular shade of pink!

The Red Hills azalea, Rhododendron colemanii, is a recently identified species that was for years thought to be R. alabamense.  Colors vary from white to pale pink to pale yellow.  This species is being propagated in Georgia and is usually available at native plant sales around the metro area.  Another new species known as the “May white” azalea, Rhododendron eastmanii, is not as available.  Both of them bloom about the same time.  For an excellent article on these two “new” azaleas, please check this article from the newsletter of the Georgia Native Plant Society.

Rhododendron calendulaceum

The Flame azalea, Rhododendron calendulaceum, would make a good selection for the next one in the bloom cycle. It has been found blooming in May in north Georgia.  Flowers are described as the largest of the native azaleas and have a brilliant range from yellow to orange to deep red. One of the larger forms, it ranges up to 12 feet.  Here is a picture I took at Southern Highlands Reserve; it was grown from seed collected on Gregory Bald.

In late May, swamp azalea, Rhododendron viscosum, starts to bloom with fragrant white flowers.  This is another tall species, reaching 15 feet.  The swamp azalea has been used successfully in hybridization programs to create beautiful new cultivars.  I have one of them: ‘Millennium’ which is a deep pink and has a light fragrance from the R. viscosum parent; the color is thought to be from R. prunifolium.  The blue-green color of the leaves is an extra bonus.

Rhododendron viscosum

Smooth azalea, Rhododendron arborescens, is sweetly fragrant with white blooms. Another tall form, it is often found in moist environments such as streamsides.  The stems are noticeably smoother than other azaleas, but another common name – sweet azalea – refers to the excellent fragrance.  I have both the species and one of the cultivars known as ‘Popcorn’.


Plumleaf azalea (Rhododendron prunifolium) is one of my favorites and the last to bloom for me.  Naturally found in southwestern Georgia within a 100-mile radius, this species was one of the inspirations for Callaway Gardens in order to preserve this rare plant and its habitat. It is their signature flower and part of their logo.  It is also remarkably easy to propagate and grow, reaching heights up to 15 feet.  The one next to my front porch has thrived, blooming every year in late June through mid-July and delighting both me and the hummingbirds in the process.  This picture was taken July 16, 2011.

Rhododendron prunifolium

Rhododendron serrulatum (now considered a form of R. viscosum) is considered the latest bloomer of all, blooming in August and even into September in some areas.  Commonly called hammocksweet azalea, the flowers are small, white and fragrant.   

So there you have it – a veritable parade of blooms if you plan it right.  You can have azaleas blooming potentially from late March to early September with the right combination of species and cultivars.  If you'd like to find some of these azaleas, check out the annual plant sale of the Georgia Native Plant Society this coming weekend in Marietta (April 14, 2012).  There will be lots of different ones there.

Sunday, April 1, 2012

A Pocket-ful of Wildflowers

I spent this past Sunday on a field trip with the Georgia Botanical Society exploring a popular wildflower trail: the Shirley Miller Wildflower Trail in Walker County.  It is known more casually as "The Pocket at Pigeon Mountain".  In the springtime it is a work in progress - you can see different plants in bloom depending on when you go.  With this year's warmer and earlier spring, some of the flowers that I saw in April 2009 were mostly finished blooming even though I went 2 weeks earlier this year.

Wild hyacinth, Camassia scilloides
Camassia scilloides

The land is managed as the Crockford–Pigeon Mountain Wildlife Management Area and a GORP pass is now required.  The erosion of limestone and sandstone in the area has created unusual rock formations including towering sandstone bluffs near the falls.  I get the feeling that it is an interesting hiking area regardless of the flowers!

Whenever you go in the spring, it's a beautiful place and the boardwalk makes for easy walking for much of the way.  Only the adventurous folks need to carry on to the falls beyond the end of the boardwalk. Here are some pictures from the trip.

False garlic (Nothoscordum bivalve) and walking fern (Asplenium rhizophyllum) are two of the unusual things.  Four trillium species are found there - the two shown plus Trillium cuneatum and Trillium lancifolium (see my earlier post for pictures of those).

Nothoscordum bivalve

Asplenium rhizophyllum

Trillium decumbens

Bent trillium, Trillium flexipes

While many of the plants there are very special - growing in a unique environment - there are many of them that can be at home in a north Georgia garden.  The next set of pictures are still all from the trip, but I have these same plants in my garden:

Red columbine, Aquilegia canadensis

Spotted geranium, Geranium maculatum

Dwarf iris, Iris cristata

Scorpionweed, Phacelia bipinnatifida

Woodland phlox, Phlox divaricata

Woodland stonecrop, Sedum ternatum

There are a large number of blue flowers represented - besides the ones pictured there were several species of Viola (violets), the very popular Virginia bluebells (Mertensia virginica), bluestar (Amsonia tabernaemontana) , and wild comfrey (Cynoglossum virginianum).

As you can see from the blog I linked to at the beginning, it looks like much is yet to bloom and it would certainly be worth another trip back this year.