Sunday, November 26, 2017

Big Trees

This is the time of year when big canopy oaks really shine: their wide crowns tower above the trees around them, their fall color glowing deep browns and burgundies in the sunshine. I decided that I wanted to find some while the color was good. With the amount of development in our area, being able to find accessible big trees can be tough. I remembered one public place where I’ve seen a lot of big oaks: Big Trees Forest Preserve in Sandy Springs.

For several years now I’ve led a winter field trip to Big Trees in January for the Georgia Botanical Society. The point of the trip is woody plant identification; the place is loaded with different native shrub and tree species. It also has some invasive woody plants which we point out in the interest of education since these are common invasive plants found throughout the metro area. This was going to be a chance for me to see these plants with their leaves on (mostly).

Big Trees is a 30-acre sanctuary that was assembled beginning in 1990 to save some beautiful trees from nearby development. You can learn more about the history and John Ripley Forbes, the man who started it, here. Big Trees has a system of trails and, if you plan to go, I recommend that you download a copy of the trail map from here as local copies are not always available. Recent improvements include a bathroom at the entrance.

White oak (Quercus alba)
A group of large white oak (Quercus alba) trees can be found on the Big Trees Loop trail not far from the entrance. Shaggy bark is characteristic of this species, but one particular individual there has bark that is especially shaggy (and has been that way for years). White oak can also have beautiful fall leaf color and these trees were glowing in the bright fall sunshine.

From there I usually follow the Powers Branch trail to the Back 20 Connector and then follow the lower branch of the Backcountry trail. This takes you along a creek and through a gorgeous American beech forest (Fagus grandifolia) that was showing color from chalkbark maple (Acer leucoderme) and sourwood (Oxydendrum arboreum). About halfway along the path, I take the short Spring Hollow trail to get back to the Powers Branch trail. This follows the gurgling stream back towards the entrance, crossing several bridges and hopping over some sturdy rocks (fun for kids). I passed one family teaching their kids how to skip rocks.

Chalkbark maple (Acer leucoderme)
Large white oaks continue to be a major part of the canopy, but some of the red oaks are there as well. Sourwood is also very common (which is awesome) and several species of hickory (Carya spp.) join the beeches in providing yellow color.

The shrub layer is still chiming in with a little color; I found mapleleaf viburnum (Viburnum acerifolium), sweetshrub (Calycanthus floridus), hearts a bustin’ (Euonymus americanus), highbush blueberry (Vaccinium corymbosum), and the evergreen mountain laurel (Kalmia latifolia). 

American beech (Fagus grandifolia)
Several parts of the trail have non-native shrubs, most of which are evergreen: small-leaf privet (Ligustrum sinense), two species of Elaeagnus, small-leaf Japanese holly (Ilex crenata). Bush honeysuckle (Lonicera maacki, perhaps) is gaining ground on the Big Trees Loop. Wisteria vine and the privet were cut back heavily at one point but they are returning.

Quercus alba
Sandy Springs has incredibly beautiful native oaks all along Roswell Road. I had to pull over several times to check out several especially colorful red oaks (I could not always determine if they were scarlet oaks or northern red oaks but the colors were intense!). I hope that more of them can remain in place over the years, but I doubt that they will be appreciated for what they are. Unfortunately, too many of our native trees are removed and then replaced with crape myrtles, Leland cypress, and other non-native trees. I saw one gorgeous white oak near baseball fields in Morgan Falls and they had planted non-native pistache (Pistacia chinensis) trees in front of it. As if they could compete!

Enjoy the fall color of the oaks while it lasts. Please spread the word that these big trees are specimens to be treasured. It takes a lifetime to grow one – it takes several lifetimes to appreciate them.

Sunday, November 19, 2017

Small Trees with Good Fall Color

Wow, was that the fastest fall ever? Actually no, it’s not over yet, but not everyone appreciates the deep fall tones of the native oaks. And not everyone can have an oak in their yard – oaks are called canopy trees for a reason. Yards seem to be getting smaller so it stands to reason that folks might like some small tree recommendations and that is what this post is about. In some cases, large shrubs can work as well.

Serviceberry (Amelanchier laevis)
Serviceberry (Amelanchier sp.) is a small to medium tree depending on what species you select. It is also one of the more available native trees, especially thanks to a few cultivars that have been developed. It is one of the first native trees to bloom. I have written about it before as a good plant to support fruit-loving birds. The fall color is outstanding, especially on trees in full sun.

Flowering dogwood (Cornus florida) is a Southern classic but not everyone realizes how good the fall color is until the plants turn glorious shades of red and burgundy. This one is good for part shade conditions, especially afternoon shade. It is also a good plant for fruit-loving birds. I have written about flowering dogwood’s cousins before. Those species are large shrubs and small trees also, but the fall color is not very showy in my experience.

Flowering dogwood (Cornus florida)

Chalkbark maple (Acer leucoderme) is one of the smaller native maples. Mostly found in the northern half of Georgia, it has a small range in the upper Coastal Plain according to USDA.  Its leaves resemble small versions of sugar maple (Acer saccharum) and the fall color is similar but more intense. I love watching the roadside near me for the annual coloring of a small grove of chalkbark maple trees. It was gorgeous as ever this year. A similar tree is Florida maple, and I have written about that one in my backyard before.

Chalkbark maple (Acer leucoderme)
Leaves of Acer leucoderme

Viburnums in general have great fall color but they are considered shrubs. Two of the larger species have upright forms that allow them to double as small trees: blackhaw viburnum (Viburnum prunifolium) and the rusty blackhaw (V. rufidulum). Blackhaw viburnum has a more vibrant color compared to the often more muted tones of the rusty blackhaw.

Viburnum rufidulum
Viburnum prunifolium

Musclewood (Carpinus caroliniana) is another small to medium tree, slowly growing to about 30 feet. It naturally grows in woodlands where along the edges it sometimes looks more like a shrub and turns beautiful shades of red and orange. In more shade, it seems to be a bright yellow. I love its assortment of common names which include American hornbeam, ironwood, and blue beech.

Carpinus caroliniana
Carpinus caroliniana

I hope this helps you find some ideas for smaller spaces. If you’re looking for good fall color in Georgia but are not limited by size, take a look at my earlier post on Dependable Fall Color.

Sunday, November 12, 2017

A Unique Fall Flower

We have to wait all year to see one of the most unusual and beautiful flowers around: the blue gentian. The one native to my area, and I even have one naturally in my woods, is called harvestbells or soapwort gentian (Gentiana saponaria). One of five gentians native to Georgia, this one is the most widely distributed species.

Gentiana saponaria
According to Gentians of the Eastern United States, this species is found in moist woodlands and along mature streams and trails. In my experiences on plant rescues in the metro Atlanta area, we most often do find it along or near streams. We can’t always rescue it because streams are usually protected during development.

The times we have been able to do so, the plants usually do quite well. I have one that I’ve relocated to a moist area that is protected from deer, and it has several blooming stems each year. The one in my woods doesn’t get as much sun so it only has one stem with 2-3 flowers. It is just barely hanging onto the edge of the bank these days after several gully washers over the years. I should move it.

Gentiana saponaria
Recently a friend mentioned that one of the plants that she planted into a demonstration garden (after rescuing it) was having a great year. I went to take some pictures of it and was able to capture a bumble bee pollinating the flowers. Click on this link to see the video that I took; a second video on the one at my house is here and you can hear the buzzing sound she makes. The smaller bumble bees are able to squeeze into the flower to get pollen and nectar. I also noticed a large carpenter bee going after the outside base of the flower since it was too big to get inside (this is called nectar robbing since the bee performs no pollination services for the nectar).

Look for these beautiful flowers in the late summer and fall. Gentians grow in a variety of habitats so you might be surprised where you find them. Most of them are a beautiful blue, but there is a white-flowering species as well.

You can read about another gentian species that I wrote about on a hiking trip in NC. And you can read about Sabatia - another flower that is related to gentian - but I doubt many of us would have realized that because it looks so different.

Sunday, November 5, 2017

Fall Today, Gone Tomorrow?

I enjoy fall colors as much as the next person, but I like to have a little time to enjoy them. This year seems to be moving along at a rapid pace. Everything I read says that the show is late to start this year but is expected to be shorter than usual.

So today’s post is a quick and short reminder to get out there if you’re going! These pictures are from yesterday (November 4th) in Roswell.  Rain forecast for mid-week will likely take down a lot of leaves in North Georgia.

One of the lakes in Mountain Park near Roswell, GA

The lake in Leita Thompson Memorial Park in Roswell, GA

If you’re looking to create more fall color in your landscape for next year, check out my 2012 post on Dependable Fall Color.

If you’d like to better guess what you’re seeing, see my earlier blog posts by leaf color:

Mockernut hickory (Carya alba)
Red maple (Acer rubrum)

Sassafras albidum
Smooth sumac (Rhus glabra)