Sunday, November 28, 2010

Winter Twigs


The bare twigs of woody plants are quite mysterious to many people.  Without the benefit of leaves or flowers, they can be at a loss to figure out what plant stands bare before them.   But when you really look at the winter twigs of woody plants, you can see a lot more differences than you might have thought.  Here, buds swollen with the promise of spring growth already, is Aesculus pavia, the red buckeye that hummingbirds love so much:
Aesculus pavia
And here is a shrub that looks all but dead in the wintertime, no sign whatsoever of next year’s growth.  This is Calycanthus floridus, the marvelously aromatic sweetshrub or Carolina allspice.

Calycanthus floridus

 
 
If you’re interested in identifying plants in the winter, there are some basic clues that can help narrow the possibilities of what the plant might be.  I’ll cover a few of them just to help take some of the mystery out of the process.
  • Leaf arrangement: even when the leaves are gone, you can see the leaf scars of where they were. Are they opposite one another along the stem or arranged in an alternate pattern?  If you can’t see the leaf scars, remember that branches themselves were once leaves - how are the branches arranged? Focus if possible on the “twigs” – the most recent year’s woody growth.  Be careful to check in multiple places because one twig might have fallen off, making the arrangement appear to be alternate.  Both the buckeye and the sweetshrub have opposite leaves (see above pictures), and here is a Viburnum
    branch, showing off perfectly opposite twig arrangement:
Viburnum acerifolium
  • Leaves on the ground can sometimes provide a clue: this is not the most reliable approach, especially if there are a lot of different plants around, but it might give you a few things to start looking at if you recognize the leaves.  For example, you might find maple leaves, oak leaves and sassafras leaves on the ground.  But when you look at the plant in question, you notice it has opposite twig arrangement.  Of those 3 choices, maple is the only one that has oppositely arranged leaves and twigs. 

  • Leaf and bloom buds already formed can be familiar: for some people, memory is all they need to recognize a plant without leaves. Here is a picture of one of my favorite bare twig plants, American beech (Fagus grandifolia):  
Fagus grandifolia
I love the beech's distinctive cigar-shaped leaf buds with tips so pointed they look like they could stab you and draw blood.  There are other trees with pointy leaf buds, however, that could confuse you. 

Amelanchier sp.


For example, Serviceberry (Amelanchier spp.) has them, but the buds are not as long,  not uniform in shape and they have the tiniest bit of “fluff” at the tip of the bud.  If you have a good memory, you can learn to recognize what you’ve seen and identified before.

  • Leaf scars and bundle scars: some plants have very noticeable and unique leaf scars.  Leaf scars are the spots left behind when the leaf fell off.  Bundle scars can be found inside the leaf scar – they reflect where vascular bundles connected to the leaf and they can be very unique in number and in the shape of them.  You can find a great picture of a leaf scar that contains 3 bundle scars at this website (the plant is Black Gum, Nyssa sylvatica).
  • Bark characteristics: some bark is very distinctive and you can learn to recognize some trees by their bark.  You can then verify your identification with another characteristic as I mentioned before.  For example, Cornus florida (Flowering dogwood) has rather unique bark and it also has twigs that are opposite one another.  Recognize the bark and then verify it with the twigs.  While Cornus florida also has very distinctive bloom buds, not all trees are in a position to form bloom buds (for example, the tree may be in deep shade):
Cornus florida
  • Remaining fruits/seeds left clinging to the twigs: sometimes you can find fruit or seeds clinging to the branches.  Some fruit is in the form of a capsule that may open to release seed, leaving the capsule behind.  Here is a picture of the capsule on an azalea (Rhododendron sp.), you can see both open (ripe) capsules and those which are not yet ripe.  Knowing the form of the fruit might help you distinguish one plant from another.
Rhododendron sp. (Azalea)
Here is another example of two plants that look very similar if you are just examining the buds on the most recent growth.  On the left is the twig of an Oak (Quercus) and on the right is a twig of an azalea (Rhododendron).  By further examining other features (the slightly flakey bark on the azalea is often enough to distinguish the two), you can get a little closer to the right identification or at least eliminate a possibility or two.
Quercus sp.

Rhododendron sp. (Azalea)
 

I’ve only scratched the surface of a very deep topic.  For those of you that would really like the tools to identify winter twigs, I suggest you get a 10x hand lens and a good key.  If you’re in the Southeastern US, I recommend “Woody Plants of the Southeastern United States: A Winter Guide” by Ron Lance.  In addition to very detailed keys, the book has descriptions of each plant according to winter characteristics and most plants have detailed drawings of the twigs themselves (and a good glossary too).

So don’t be intimidated by those bare branches – get out there and figure it out.  I suggest starting with a tree that you already know and examining the twigs and winter features.  Good luck!

 

Sunday, November 21, 2010

Evergreens


Thank goodness the leaves are almost off the trees!  The last few weeks of color are always a dangerous time for me to be driving – I’m so busy looking at the leaves that I can hardly focus on the road!  However, the absence of deciduous leaves now reveals some “views” that are not so pleasant.  Now is the time to evaluate areas of your garden that might benefit from the screening that native evergreens can provide.

The definition of “evergreen” is of course that the plant does not drop all of its leaves come winter.  Instead these plants shed a portion of their leaves during the year while retaining others.  In our area, evergreens can be “needled” or “broadleaf”.  Needled evergreens are those like Pines, Junipers, Hemlock and our single false cypress, Chamaecyparis thyoides (Atlantic White Cedar).  Broadleaf evergreens include Hollies, Rhododendrons, Mountain Laurel and others.

As with any plants, it is important to choose site-appropriate plants to ensure that your choices thrive and that you don’t have to prune them unnecessarily to make them fit the space.  If you’re considering a hedge of plants to screen off a large view, I’d like to recommend that you create a “mixed” hedge.  A mixed hedge has several benefits: you avoid destruction by a single disease if you stay away from a monoculture; it looks more natural to have different plants; and you don’t have to limit your choice to a single plant (because there are so many good ones to choose from!).

Here are some ideas simply based on light exposure: full sun and partial shade.  Be sure to research mature size – some dwarf cultivars are available for smaller spaces. 

Full Sun:

Wax myrtle (Morella cerifera or Myrica cerifera) – Shrub to tree sized evergreen with medium green leaves, fragrant foliage and small blue-grey berries that are popular with birds.  Dwarf cultivars can be found in nurseries.
 
Eastern redcedar (Juniperus virginiana) – A soft needled tree that is technically a Juniper, it is often grown for Christmas trees. This plant is commonly found along fence lines in pastures.  The wood is very fragrant and coincidentally makes great fence posts.  Birds like to nest in these.
 
Hollies (Ilex spp.) – The evergreen hollies (there are deciduous ones too) come in all sizes from the large American holly (Ilex opaca) to the shrub-like and wet-tolerant Inkberry (Ilex glabra) to the very variably formed Yaupon holly (Ilex vomitoria) which can be a weeping tree form or a small foundation shrub.  You may be surprised to know that not all of them have spines.  If you want berries, remember to look into getting male and female forms.


Evergreen magnolias – Southern magnolia (Magnolia grandiflora) is native to coastal Georgia primarily but is available in nurseries everywhere. While many cultivars are now available, be aware that in the Piedmont region of Georgia, this plant is a bit of a pest.  Birds have dispersed seeds into natural areas where it can outcompete some of the regionally native trees.  Sweetbay magnolia (Magnolia virginiana) is another evergreen magnolia native to Georgia; it happens to tolerate wet conditions.  Here is a bloom on M. virginiana:


Pines – Pines are much maligned as desirable trees for a variety of reasons.  I think the two most common reasons are that ice storms bring out the worst in pines, and that they are very common trees. However, I think they should be considered for screening for 3 reasons: they can be very inexpensive, they grow fast and they are easy to remove when you don’t need the screen.  Loblolly pine (Pinus taeda) seedlings can be reasonably priced as seedlings from the Georgia Forestry Commission’s seedling program.  A less common but very attractive pine for North Georgia is White Pine (Pinus strobus); hands down, white pine has the prettiest cone of all pines that I’ve seen in Georgia and the blue-green needles make very soft pine straw.

Check out the Georgia Forestry Commission’s seedling program.  You can get seedlings of Wax Myrtle, Eastern Redcedar and several different pines:  Georgia Forestry Commission

Partial Shade:

Hemlock – A stately tree of mountainsides and trout streams, the Hemlock is under active attack from an invasive insect pest, the wooly adelgid.  However, I think we should keep planting them, you never know if yours might be the one with resistant genes!  Eastern hemlock (Tsuga canadensis) is the most commonly available one for purchase.  Beautiful foliage and shade tolerance make this a very desirable choice for partial shade areas.
 
Florida Anise – I love this tree (Illicium floridanum) for not only shade tolerance but also handsome foliage that is fragrant when you brush up against it.  Flower fragrance, however, can be a little “off” depending on your individual sense of smell so site it carefully.  Many people mistake this for evergreen Rhododendron when they first see it.
 
Rhododendron – In the same family as Azaleas, the evergreen Rhododendron catawbiense is the one I find most often in stores.  If you can find it, Rhododendron maximum is very handsome but a much larger plant at maturity.  Both of these prefer to grow in North Georgia (for a similar look in the rest of Georgia, see the Florida anise description above).  This is R. maximum:

 
Mountain Laurel – few plants are more dazzling in full bloom than Kalmia latifolia.  Another mountainside plant, this one can still do quite well as a garden plant in North Georgia.  I have used it as a foundation plant, and you can fit a variety of cultivars in better nurseries.  ‘Elf’ and ‘Minuet’ are two dwarf forms.  Similar to Rhododendrons, plant them a little “high” to achieve the good drainage that they need.


 
Carolina Cherry Laurel - Prunus caroliniana is good for screening and the berries are enjoyed by wildlife.  The cultivar ‘Compacta’ offers a nice dense form.  Some people find this plant a bit “weedy” because of the seedlings, similar to the issues with Southern magnolia seedlings.   

If you need help finding these plants, check out the Native Nurseries page on the Georgia Native Plant Society's website: Sources for Native Plants

Sunday, November 14, 2010

Hanging on

The first cold night of the season came through this week and blackened all our tender vegetation.  Annual salvia (Salvia coccinea) and Southern wood ferns (Thelypteris kunthii) were the first to go.  Sad as it was, I will say that the remaining red salvia blooms looked pretty stunning against the darkened foliage!

Leaves are falling quickly for many of the trees now like tuliptree and maples.  Oaks in general still have a lot of leaves and some of the showier ones like Scarlet Oak (Quercus coccinea) are even just now starting to turn color in my area.

Trees and shrubs that have lost their leaves haven’t necessarily lost their fruit, however.  I was struck this week by the look of persimmon trees (Diospyros virginiana) in my area that are bare of leaves, but still “decorated” with fruit ornaments.

 
I have a non-fruiting persimmon tree in my yard – perhaps it is a male tree (persimmon trees are dioecious) or it could be a female with no nearby males.  I have seen it flower.  I stopped at a home in my neighborhood to take pictures of the fruit on their tree.  I am always glad to be able to talk to neighbors about the special trees that they have (in the hopes that they will remember the conversation and not cut it down one day!).  I explained that the fruit is edible and delicious, as long as it is perfectly ripe.  Eating a persimmon before it’s time will surely make your mouth pucker ….  The fruit must separate easily from the stem before it is ready to eat.

While the leaves have not ALL fallen off, this mapleleaf viburnum (Viburnum acerifolium) fruit is dangling hopefully … hoping to entice birds to eat it, that is.  The fruit will remain until some bird needs it.
 
The leaves have long since fallen away from the fruits on this Chokeberry (Photinia pyrifolia formerly known as Aronia arbutifolia).  The bright polished red of the berry is such an attractive sight.  They often remain on the twigs until late winter.  Perhaps the coldest temps are needed to make them tasty.







Sumac (Rhus) is a very recognizable roadside plant (not many people invite it into their garden) whose fruits persist long into the winter.  Staghorn sumac (Rhus typhina) is probably the best looking of the genus – it’s sculpted clusters of bright red fruit attract the attention of both birds and people.

 
And this year I found a new persistent “fruit” to recognize: the dangling clusters of papery seeds borne in late fall by Boxelder (Acer negundo).  Boxelder is a member of the Maple genus (Acer) and the seeds are samaras just like other maples.   For years I have seen these on the roadside near my neighborhood.  For a while I thought the dangling seeds belonged to a Locust of some type because I never stopped to look closely.

 So keep your eyes open for the sights of these fruits that hang on after the leaves are gone and see what else you can discover.  You can be sure that as the season progresses these things will find their way into the diet of a multitude of critters!

And remember - it's still a good time to plant trees and shrubs in Georgia!





Sunday, November 7, 2010

Found Things


It’s fun to find new things that pop up unexpectedly in the garden – especially good things!  I’m not talking about weeds.  I was walking through the wooded area of my yard the other day and I found this fern.  
 
As I walked over to examine it, I realized it was growing in an area that used to be a hole.  I had filled the hole with some spare dirt and plant clippings.  The dirt must have contained some root fragments of the Southern Wood fern that I have in the front yard (Thelypteris kunthii) -  I had been trying to transplant some into pots, but I thought the plant had died in the pot.  I guess I was more successful than I thought!  That is one reason that I never truly “throw away” things like that; I have had too many things sprout later, months after I had given up on them.

The next day I was working in another area, and I spotted this colorful seedling.  It is a mapleleaf viburnum (Viburnum acerifolium) that must have been planted by a bird for me.  My mature plants have plenty of berries so the source of the seed is probably the plants about 100 feet away from this baby.

Those of us that participate in plant society plant rescues (with developer permission) often get surprises in our rescued plants.  This is especially true when you dig up plants after spring ephemerals in the area have gone dormant – trilliums (Trillium) and trout lilies (Erythronium) are two such plants.  Here is a trout lily that hitch-hiked it’s way into my garden one year.




Of course, not all found things are desirable, not even the hitch-hikers.  Many years ago I dug up a native azalea on a rescue site during the winter.  Imagine my surprise when a bracken fern (Pteridium aquilinum) popped up next to it in the spring.  Unfortunately I had planted that azalea in a very fertile environment – that bracken fern was soon popping up in the lawn nearby as far as 6 feet away!

But all in all, I’d say Mother Nature is pretty kind to me.  I hope she will continue to send these surprises my way!