Botanica Atlanta - Landscape Design, Construction & Maintenance

“Huzzah! Her sides are made of iron!” a sailor reportedly exclaimed.

Image: Anton Otto Fischer

It was August 19, 1812 and the British HMS Guerriere was trading gunshots and cannon blasts with the USS Constitution. America’s USS Constitution, which would – from the moment of that exclamation forward – be nicknamed “Old Ironsides,” was a warship named by George Washington and put together with copper fittings that were forged by Paul Revere. Much to the concern of the HMS Guerriere at the time, she was also manned by a crew of more than 400, armed with around fifty cannon, and shielded with a twenty-one-inch thick hull that was in fact wood, not iron. This tough hull was constructed with materials from  several different tree species, but perhaps most significant were the shallow-arced and unprecedentedly tough members cut and milled from southern live oak trees in St. Simons, Georgia.

Back on dry land, in the coastal regions of the Southeast, to be specific, southern live oak (Quercus virginiana) is one of the most distinct plant species in the landscape.

Image: Al Benas

The low-sprawling, convoluted, and gnarled branches of the southern live oak give the species an easily identifiable and visually powerful “architecture”. The tree’s form is able to dominate landscapes in a way that few other species can.

A large part of the visual character of live oaks has little to do with the trees themselves. The humid, warm areas of the continent where southern live oaks take on their best form also happens to be a perfect growing climate for Tillandsia usneoides, the organism that we refer to as Spanish Moss. A botanist or ecologist would inform you that Spanish moss is actually not a moss at all but instead a type of suspended plant called an epiphyte that absorbs its nutrients from rain, dust, and air. They also might tell you that the relationship that this draping, ghostly gray-green plant has with the southern live oak is defined as commensalism. This means that the Tillandsia benefits from its relationship with the tree, while the Quercus is neither harmed nor benefited. Judging by the strong association that we humans hold between the two plants, and the way that the dramatic, billowing stems can play tricks on our eyes at twilight, I would certainly say the tree benefits as well, even if only in the eye of the beholder.

Images: Kelly Johnson and Gail Des Jardin

As with most trees of any lasting value, southern live oaks are not fast growers. In fact, many of the specimens that we admire for their ancient character are nearly a century old, if not older. But these are trees that we must plant for our children and grandchildren, not only for ourselves.

It is not easy for me to think of a tree species that has more of a visual weight and aesthetic dominance in a landscape than Quercus virginiana. When I picture the southeastern coast, it is the baroque beauty of southern live oaks that comes to the foreground of my mind. These trees dominate any landscape in which they grow, just as they dominate my picture of the entire region, and surely there is a good reason for that.

Image: Gloria Manna

Author: Sam Valentine, BLA, LEED AP

Image: James Morley

Trees. Shrubs. Perennials. Annuals. Can you spot the garden plant missing from this list? It is often easy to leave vines off of your planting list, but these sprawling, climbing organisms are one of the most flexible, fast-growing, and potentially beautiful plants that can take root in your garden. The varying species of vines, ranging from roses to cucumbers, have much to offer a landscape, and they are able to bear fruit, blossom in vibrant colors, create shade cover, and provide visual interest.

Now that you are excitedly pondering what vine species you will plant to add life to your garden, there are a few important concepts that I would recommend you consider first:

First off, if you want to ensure the success of your new plants, you should make sure that the vine you select is known to flourish in your specific plant hardiness zone.  [To determine your garden’s plant hardiness zone check out the interactive map at PlantMaps.com.]  Depending on what region of the country – or perhaps what part of the world – your plant is native to, its success in northern Georgia, largely described as “Zone 7b”, may vary. If you are planning to train your climber on a trellis or wall, it may remain evergreen through most winters, it may die to the ground in cold months, or it might not survive at all, and the plant’s success can pretty accurately be determined by comparing its native zone to your own.

Image: Graham Keen

Next, I would consider the growth rate of the vine in relation to your intended use. Semi-transparent wall covering? Quick, dense coverage of a trellis or pergola? One great strength that is unique to vines is that, when given a structure, they will generally grow to match that form. Trained onto the right structure, a climber can provide a large amount of visual beauty and shade, even growing to cover and cool a wall from a modest container planting on a hard patio.

Finally, I would recommend that you assess the vine species’ method of climbing. Different vines have different specialized parts which they use to climb up vertical faces and gain sun exposure, some even using thorns as grappling hooks. Others twist around, adhere to, or spiral up anything they can grasp, and a rare few species even stick invasive feelers under the bark of a tree and covertly climb under the skin. Each of these various climbing mechanisms will have different implications for fences, walls, trellises, and trees that the vines might be scaling.  

 Image: Kai Yan

As some vines grow, they twine their stems around a support. This group of vines, which includes Carolina Jessamine (Gelsemium sempervirens) cannot climb smooth vertical faces such as board fences or brick walls without the assistance of a trellis.

Image: Matthew High

Other vines, including Trumpet Vine (Campsis radicans), put out winding petioles or tendrils to aid in their race to the top. Similar to twining vines, these vines require the help of a ladder to climb smooth surfaces, but they have no trouble covering picket fences or shrubs.

Images: Mark Kent and Donna Runner

Perhaps the most recognizable biological mechanism that vines use to scale walls are clinging roots. Climbing Hydrangea (Hydrangea petiolaris) and Creeping Fig (Ficus pumila) are some of the most beautiful examples of these aerial-rooted vines, but the invasive English Ivy (Hedera helix) is probably the most widespread and memorable.

Any gardener who has spent time pulling the woody, non-native English Ivy off of their fences, down from their trees, or even out of their garden beds has learned the lesson of planting too aggressive of a vine. In my opinion, the easiest way to avoid experiences like this is to give preference to native plants which are less likely to get out of control.

Vines are versatile, forgiving, and beneficial plants. If given sunlight, water, and some occasional pruning, they can provide you with flowers, fruit, and shade. When trellised over a patio, a deciduous vine will block the hot summer sun’s rays, but the same vine can also allow warming light to penetrate during winter. Allowing vines to trail over a pathway arbor can imitate the canopy of a tree-lined walk. Vines truly are shape-shifting plants that possess great landscape value.

Image: Brett Woodvine

 Author: Sam Valentine, BLA, LEED AP

The native azalea is something of an exotic in the woodland garden, but many are native to Georgia.  They are uncommon enough in the “civilized” landscape – one that is conceived in full or in part by man – that they are often misidentified.  Looking more like rhododendrons but blooming before, with and later than azaleas they are also the victims of second guess…surely that can’t be an azalea?!

Photo credit: Donald Hyatt

Native azaleas grow from Florida to the northeastern Unites States, but most are found in the southeast.  They are most commonly found in higher elevations where temperatures are cooler, but several thrive in the Atlanta landscape if sited properly and well maintained.  Here are three that are in bloom now:

The Oconee azalea (Rhododendron flammeum) blooms orange to red from mid-April to mid-May.  It is able to withstand heat and drought and is found only in Georgia and South Carolina, according to the USDA Plant Database.  It appeared on the scene sometime during the late 1700’s.

Photo credit: Donald Hyatt

The Alabama azalea (Rhododendron alabamense) is found in Mississippi, Alabama, Tennessee Georgia, South Carolina and Florida.  Its fragrant blooms are white, with a bit of yellow towards the center.  It also blooms from mid-April to mid-May. It was first recorded in 1883.

Photo credit: Donald Hyatt

The Alabama azalea self-propagates by underground stems or stolons and softwood cuttings can be successfully rooted.

Photo credit - Steve Baskauf, courtesy of University of Tennessee Herbarium

Pinxterbloom azalea (Rhododendron periclymenoides) blooms pink to white, also mid-April to mid-May.  The blooms are somewhat fragrant.  

Photo credit: Thomas G Barnes

Pinxterbloom azalea stands anywhere from four to ten feet at maturity.  It was first introduced in England in 1734.

Photo credit: Donald Hyatt

If you have shade, a soil pH of about 4.5 to 5.5 and a slightly to moderately moist site (or a legal source of water during drought), consider some native azaleas in your Georgia landscape, and keep the neighbors guessing.

Author: Cloud Q. Conrad

Forsythia (Forsythia x intermedia) is one of those unsung heroes in the landscape. Through the year forsythia fades into the background. After all, its foliage isn't very exciting and its form unremarkable. And it's so low maintenance that it is easy to forget. But in late February and early March, forsythia is once again valued for its role in the garden - to brighten up gray winter days and to remind us that spring is just around the corner.

Photo credit: Susan Schurr

Forsythia is named for William Forsyth, one of the founders of the Royal Horticultural Society. Native to Asia and the Orient, forsythia has about a dozen species and many hybrids.

Photo credit: The Gardeners' Network

Site forsythia in full sun to partial sun in zones 4 - 8. Forsythia makes no particular demands on its environment or owners. Forsythia will thrive in average soil, in drought and in pollution. This shrub does not typically have pest or fungus problems. Reaching average heights of 6 - 8 feet or more, forsythia grows about a foot or more per year and benefits from pruning to shape, promote bushiness and blooms, or confine to a particular size. Forsythia blooms on old wood, so prune just after blooms are spent to get the most color from your shrub. This is also the best time to fertilize with an all-purpose 10-10-10 garden fertilizer. New plants can be propagated by cutting or layering.

Landscape designers use forsythia to screen a view, draw attention to other plants with winter interest, mask electrical poles and guy wires or electrical boxes, or create a hedge. But the real payoff comes in the dead of winter, when the days are short and the skies are bleak. Forsythia is a ray of sunshine and a vision of hope for the coming of spring.

Author: Cloud Q. Conrad

Cooler temperatures and ample rain bring our attention towards fall landscape planting and many of us have started to make lists of new perennials to be added to our gardens this fall. We'll be devoting several posts to some prized plants that you might consider planting this fall.

Helleborus orientalis. Photo credit: Cloud Conrad

Helleborus orientalis is one to consider if you don't already have several in your shade gardens. Hellebores, or lenten rose, are glossy, dark green-leaved, evergreen perennials which self sow readily in mostly shady conditions.

They are expensive - there's no getting around that fact. But hellebores will more than pay you back your original investment, if you leave their blooms alone and let the beautiful black seeds develop and disperse amongst your pine bark mulch.

Hellebores bloom in late winter and the blooms last until late spring. The blooms arrive during the Christian season of Lent, hence the common name lenten rose. The seedlings will take a few years to bloom but once they do you'll enjoy a naturalizing effect that is dramatic and unique. Their blooms are not really petals but modified calyxs, which accounts for their long "bloom" time, according to Plant Delights Nursery. 

Seedlings rarely produce the same bloom color as their parents, but you'll not be disappointed because the blooms of the hellebore generally start one color and morph to another through the season. This transition is so interesting you'll forget all about the color you expected.

Hellebores generally stand a foot and a half high and spread as wide when mature. All parts of Helleborus orientalis are poisonous. Hellebores are deer resistant and can tolerate dry soil. Hellebores are perfect for the woodland garden or border, as groundcover or specimen planting. Native to Asia minor, hellebores grow throughout the US, from zone 4A to 9A.

Hellebores are beautiful year-round and look especially good paired with golden acorus (sweet flag), autumn fern, golden creeping jenny, false solomon's seal, hakonechloa, dwarf cypresses, and red and purple leaf Japanese maples. Ask your landscape designer whether you have a good spot for Helleborus orientalis in your landscape.  For more information, visit the Hellebore Society 

The early daffodils are starting to bloom and the rest are up and running despite the cool weather.  For generations these simple flowers have given pleasure to gardeners and poets alike.  So it may come as surprise to some that these bright spring flowers were not always popular.

Wild, simple, but attractive early daffodils.

Wild daffodils tend to be the earliest and simplest blooming variety, and the colonial home owners rated them just about on a par with those bright orange ditch lillies that grow on the roadside today. It was the mid 19th century before someone brought the idea to America that daffodils in lawns looked attractive. This took a little while to come to the south, but by 1900 it seems certain that they were catching on everywhere.

According to Sara Van Beck, a daffodil historian, the flowers were also planted on gravesites. Curiously, if you visit old graveyards in small North Georgia towns, you will see slightly different varieties of daffodils growing in each one. Each village or town seem to exclusively use one preferred type. 

Old fashioned, early daffodils.

The early old fashioned daffodils in this picture are likely Telamonius plenus, or Van Sion (which are two names for the same variety) This variety is colloquially known as the Easter Flower or Butter and Eggs. It has a double bloom, and was very common in 19th century homes and estates.

At the last meeting of the Atlanta Permaculture Meetup group, one of the leaders of the group mentioned that black tea grows very well in our neck of the woods. I decided to do some research and found some facts that I thought were very interesting.

Tea Camellia (Camellia sinensis)

First of all, the plant from which black tea is made (that's the regular "tea bag" type of tea found in the grocery store) is the Camellia sinensis. According to this article, the Southeast has excellent growing conditions for this plant but, for some reason that is unknown to me, it is only being grown on one farm in Charleston, SC. The article also says that green tea and oolong tea are made from this same plant. The only difference is in the processing of the leaves.

Also at our last meeting, I remember someone asking me if olives can be grown in Georgia. I found out that olive trees don't flourish in humid climates or in slow-draining soils (like clay), so I suppose it would be futile to attempt to grow them here. But I also found out that another type of Camellia can be used to make an oil that is very similar to olive oil. Here is an article about it. The oil is made from the seeds of the Camellia oleifera and is the primary cooking oil used in Southern China. All that is needed to extract the oil is a hand-cranked expeller like this one.

As of 2002, this plant was being grown on a trial basis near Savannah to determine if oil production from it is viable for Georgia. Here is an article about that. I am going to try to contact the man who wrote the article to see if I can find out the results of the trial.

All of the Camellias are well-suited to the Georgia climate and soil, so it seems that anyone could produce his own tea and olive oil substitute right here. And all of the camellias are densely growing evergreens that display showy flowers and glossy green foliage when most plants are barren, so you get a plant that beautifies the landscape and produces useful substances as well. In addition, as far as I know, none of the Camellias require full sun and all are relatively pest and disease resistant, so it seems to me that they are ideal for a forest garden setting if they get a good daily dose of filtered sunlight or a woodland edge where they get half a day of direct sunlight.

After the scares of the past few years with contaminated supermarket food, many families are looking to grow at least some of their food at home. Alas, when considering fruit, most people think of peaches and apples, but there are many more, troublefree fruit that you can grow in the garden.

Figs are one of the old fashioned shrubs that went out of style many years ago, but is making a welcome comeback.  The common fig (Ficus carica) is a terrific looking shrub for any garden, but does get quite large over the years, so give it plenty of room.  The fruit is like a small brown pear, with a soft light brown pulp which ripens in late summer. Fortunately you do not need a pollinator for this fruit, so a single shrub will yield plenty for your family.

Mulberries are another tree that is from the past and many of us know it from the nursery rhyme.  Mulberries though form quite a good size tree that makes a good shade tree in the garden as well as producing fruit.  A brilliant yellow fall foliage is an additional attribute to this easy to grow tree.

The Bright Yellow Fall Colors on a Mulberry Tree

Other fruits that can be grown include both the fuzzy and smooth skinned Kiwi (Actindia chinensis), Pomegranate (Punica granatum), and Paw Paw (Asimia triloba).

For more about growing uncommon fruits, see the UGA publication entitled "Minor Fruits and Nuts in Georgia."

Everyone has seen the beauty of apples in blossom each spring, but not so many are familiar with the blossom of the quince bush.  This bright red blossom appears before the leaves come out and brighten the rather bland late winter landscapes. 
 

The quince fruit comes from the bush Cydonia oblonga which is a genus containing just the one shrub.  Remarkably, this shrub has not yet caught the attention of the hybridizers, and so remains essentially the same thing that was grown in gardens by our grandparents.

Quince does tend to come in two forms though, albeit that they have the same name, so pick your plant carefully.  Look for one with strong upward growth rather than one with a group of lateral branches that spread over the ground.  Both seem to produce fruit, but the upright version makes a much better shrub in the landscape. 

The new growth is mid brown and has a slightly chestnut tinge to it.  These mature to dark stems.  The mature stems also have long barbs on them!  A mature bush will grow to about six to ten feet in height, and the same across.  The bright orange/red flowers arrive in early spring before the leaves, and by late summer the squat pear-shaped fruit will mature. When ripe the skin is thick and yellow, and the fruit is hard.

Old upright quince bushes can be rejuvenated, if care and time is taken.  Some new growth occurs each year from the crown.  Remove some of the oldest branches to encourage these new stems. If this is done over a matter of several years, the whole bush will return to health. Fruit is borne on the newer branches, so encouraging new growth will also increase the fruit production.

Quince fruit can be made into jams and jellies which are a bright pink in color. For a recipe see:

http://www.elise.com/recipes/archives/001455quince_jelly.php

The south has long, hot and humid summers when just walking outside can be exhausting. As summer nights lengthen and cool slightly, some shrubs step forward to take center stage and exotic blooms and heady fragrances fill the fresh autumn air. Camellias and Tea Olives are two classic evergreen shrubs that bloom at the end of summer and continue throughout winter, depending on variety.

Camellia

The most common late season blooming shrub is the camellia.  Late summer into early spring is when these shrubs put on their colorful show.  Camellia sasanqua blooms first with bright pink, red or white blooms, which can be single or double.  Some of these are also sweetly scented, so plant them where you can walk by and take advantage of this trait.

Winter through early spring is when the Camellia japonica is in bloom.  The flowers are very similar to Camellia sasanqua, and provide a welcome bloom when very little else is around.

Camellias grow in a variety of conditions but do best with some sunshine.  Full sun is possible as is part sun.  As with many shrubs, camellias with very light colored flowers will do better with some afternoon shade.  Both wind and blazing sun can create a burnt edge to delicate flowers.  Once established, they can survive droughts well and are mostly bug free.

                   Camellia sasanqua

For more information on growing camellias, see the website of the American Camellia Society.

Tea Olive

This is another wonderful fall through winter flowering evergreen shrub.  The tea olive (Osmanthus fragrans) produces an abundance of tiny yellow flowers that are heavily scented.  Tea olives enjoy a similar environment to camellia and once established they survive with very little attention.

                      Osmanthus fragrans

Other shrubs in the landscape that put on a second show are the repeat azaleas and reblooming roses.  Both of these bloom early in the year and tend to peter out during hot weather. They rebound though when late summer weather arrives to give added color to your fall landscape.