Sunday, December 26, 2010

Winter Weeds

With most plants dormant here now, it is easy to spot evergreen plants.  Evergreen plants are a welcome sight in winter, offering a tangible sign of life in an otherwise dead-looking landscape.  Unfortunately, some of the most noticeable evergreen plants are invasive non-native plants.  We can use our ability to spot these plants to our advantage, however.  Now is a good time to find these plants and remove them from your landscape and on restoration projects.
Tsuga canadensis - a native evergreen
Here are six of the most prevalent invasives that are evergreen.  They are all woody plants and can be removed in at least two different ways.  If they are young and small, try pulling them out now while the ground is relatively moist (wear gloves to ensure good traction and minimize any reaction – English ivy can cause a rash).  If they are too large to pull, you can cut them and carefully apply (consider using a foam paintbrush) a bit of brush killer on the stump.  At the very least, remove any berries on the plant and mark the plants with some bright string or flagging tape (available at home improvement stores) so that you can come back to remove them properly in the spring.  Bag up any berries and place them in the trash.

Ligustrum sinense
The first plant is probably the most invasive plant in our area – it has disturbed more acres than any other plant and has naturalized so widely that some folks think it IS native.  Chinese privet (Ligustrum sinense) is known by many folks as “hedge” because it has been used for many years as a hedge plant. This plant has small leaves that are oppositely arranged on the stem and is considered to be a shrub or small tree. 

Chinese privet seedling

This plant is very adaptable and grows in both fairly dry areas and floodplains.  It spreads by berries (drupes) and by roots, often creating dense thickets.  The first few sets of true leaves on seedlings have a distinctly wavy look on the edges.  I usually find seedlings when I am bent over pulling out japanese honeysuckle.
Chinese privet thicket

Ligustrum japonicum

It’s cousin, Waxleaf ligustrum (Ligustrum japonicum) is becoming more invasive thanks to increased usage in landscape designs and availability in nurseries.  It has larger, more glossy leaves and very similar fruit.  This picture was taken in a wooded roadside where the plant has naturalized.  Shade tolerance has allowed all forms of Ligustrum to invade woodland natural areas like state parks; these parks are now forced to spend resources on eradicating it and to host “privet pull” workdays (a great way to donate some community service, by the way).

Lonicera japonica

Japanese honeysuckle (Lonicera japonica) has been a favorite of homeowners for generations because of its sweet smelling flowers and ease of cultivation.  Who among us has not pulled apart the white and yellow flowers to taste the sweet nectar? This rampant vine is capable of smothering less aggressive plants, shading out anything that might grow beneath it.  This picture was taken two houses away from me – the vine has grown twenty feet up the young pine trees and the base of it is now as wide as my wrist.  Evergreen leaves and pale flakey bark are key identifiers in winter; you may also see small dark blue berries.  If you look carefully, the leaves are arranged opposite one another although they may appear to be in whorls.

English ivy infestation

Another old-fashioned favorite gone bonkers is 
English ivy (Hedera helix).  Once prized in many a 
garden in Atlanta, it can now be found high in the 
tops of large trees throughout old, established 
neighborhoods.  The good intentions of many folks 
to “keep it contained” are not always kept, especially 
when properties change hands.  

English ivy seedling
An interesting fact about this non-native vine is that it only becomes mature enough to flower and set fruit (blue berries) when it is allowed to climb.  When kept confined to the ground, it remains in a juvenile form.  However, even there it is an aggressive and thick vine, shading out all that would try to grow underneath.  Many people that eradicate it report having native plants like Trillium and other spring ephemerals spring up once it is removed.  Watch out for early signs of infestation when neighboring properties have it in their trees – new plants are easily eradicated when they are young.

Mahonia bealei
Mahonia is often mistaken for a mutant holly plant, but it is a member of the barberry family.  Mahonia bealei is the aggressive European species that invades our wooded areas.  There is a species that is native to the Pacific Northwest which has the common name of “Oregon grapeholly”. A stout and prickly shrub, it has thick, shiny leaves, yellow winter flowers and bright blue drupes in the spring.  Someone once commented that a particularly large specimen on the side of the road looked like a “prehistoric” plant.  It was rather scary looking.

Nandina seedling
Bright red clusters of winter berries have earned Nandina a special place in the designs of winter decorations … and in the forests of the southeast!  Nandina domestica, also known as Heavenly bamboo, is a shrub with compound evergreen leaves.  A very invasive plant in Florida and south Georgia, the increasing warmth of the northern part of the state has allowed this plant to become more invasive in the last decade.  I regularly spot it now on roadsides and ditches as well as wooded areas.  Learn to spot those seedlings early so that you can pull them out while the pulling is still easy!

Elaeagnus (thorny)
Elaeagnus has the disreputable nickname of “Ugly Agnes” thanks to its rambunctious and untidy growth habit.  With regular sheering it can be a solid and substantial hedge shrub, but too often it is allowed to do what it wants.  Long whips of new growth allow it to grow almost vine-like into adjacent shrubs and trees.  My neighbors inherited these unruly shrubs when they bought the house 3 years ago; the previous neighbor spent hours keeping them trimmed.  The unsuspecting and overworked new owners ignored the shrubs … until their rampant growth toppled a mature Yaupon holly into the street.  I showed the homeowner how to cut the Elaeagnus away from the Yaupon, allowing it to spring back into a vertical growth position.  You can recognize Elaeagnus by its glossy green leaves with silver-colored backs, the intensely fragrant flowers and the bright red berries.  Some forms, like this seedling in my other neighbor’s yard, have thorns as well.  You can find this shrub along many interstate roads where it was planted for years by the Department of Transportation.

Interested in identifying other invasives? This is a good website – detailed photos for identification and links to learn more about methods of control for invasive plants in the Eastern United States.  Plants are listed both by common name and by scientific name – use your browser’s “Find” function to search for what you’re looking for (but be aware that the common name be not be the same as what you know it as, so search by scientific name if possible).

By the way, the first picture in the blog is a young eastern hemlock (Tsuga canadensis) growing in my yard.  We got snow on Christmas Day, and I took this picture then.  It’s not a weed!

Sunday, December 19, 2010

Inspired by Nature

It is a delight to find beauty in nature no matter what the season.  Of course, I suppose it depends on your perspective of beauty.  For me this time of year it can be the silhouette of a deciduous tree’s branches against a grey sky ... or the pale brown leaves of American Beech (Fagus grandifolia) that remain on the young trees in a wooded area.  
The view from my back deck today

These images and many others come back to me when I’m deciding what to plant in my own yard.  I remember the silhouette of the large tree’s branches, and I am inspired to include some trees - like oaks - that will one day be large enough to create that effect.  I remember the leaves of the young beech trees, and I promise myself to rescue a few beech trees on my next rescue so that I can add some more to my yard.  Those leaves that stay in winter provide movement when the wind blows as well as some measure of privacy.  By late winter, they have faded to the color of antique lace, gracefully enrobing the branches.

Nature has some really good ideas!  This picture helps me remember that moss glows like a jewel in the wintertime, providing color and life in an otherwise brown winter landscape.  It helps me remember that I need to let moss grow where it plants itself, and I need to move bits of it into new places so that I can have more of these cheery patches of green.  Moss is also a great “nursery” plant, allowing the seeds of other plants to stay moist and fostering germination.
Sedum ternatum in moss
This picture reminds me to leave things where they land.  This log is sporting a healthy crop of moss, allowing it to become a nursery log.  The decomposing wood will feed thousands of insects, support the growth of fungi, and might be a home for small mammals.
These two pictures show me that plants naturally spring up in the oddest of places: this is Rue Anemone (Thalictrum thalictroides) next to a moss covered root
Rue Anemone (Thalictrum thalictroides)
Trillium luteum

and Yellow trillium (Trillium luteum) sprouting up from a clutch of rocks.  If I want to recreate some of nature’s good ideas, these are the concepts to remember. 

Here is a picture that challenged my perception of color combinations.  I don’t know that I would have put these plants together on my own, but they looked fabulous together when I came across them on a field trip to the Pocket in North Georgia.  The red/yellow flower is Red Columbine (Aquilegia canadensis), the purple flower is Scorpion-weed (Phacelia bipinnatifida) and there is a white flowering Sedum ternatum in there as well.
Scorpion-weed, Red Columbine and Sedum
I hope that you might consider that nature can inspire you too.  Take pictures to help you remember how a tumble of lichen-covered rocks on the trail looked so picturesque and how that sweep of ferns around the bend was just right.  Find a way to incorporate those ideas into your landscape and bring a bit of nature home with you.

Sunday, December 12, 2010

Winter Reading

It’s not actually winter here – that official date is still 9 days away.  Yet the cold weather has been intense (and long) enough to make me feel like I’m already there.  Perhaps we’ll catch a break and warm up at some point, but until then I’ve got to think like it’s winter.  And that means staying inside.

I find reading to be a great cold weather activity.  All spring, summer and fall I am too busy to read – too busy being outside!  Here are some of my favorite gardening books and why.

Bringing Nature Home by Douglas Tallamy is the one that has impressed me the most in the last few years.  I got it during the 2007 winter holiday, and I think it is time to read it again.  Re-reading books often brings out new insights and perspectives because you are not the same person that read it the first time.

This book is a very “easy” read – entertaining, informative, and easy to follow from one chapter to the next.  I would say that for the last 3 years it has been the single most effective book in explaining why native plants are important.  People all over the country are reading this book and smacking their heads while thinking: “Of course, it all makes perfect sense now!” Here is a book review that I wrote on it for the native plant society.

Viburnum nudum var. cassinoides

Viburnums by Michael Dirr is both a reference book and a fabulous collection of beautiful pictures.  The book includes both native and non-native viburnums, so just skip past the non-natives, ok?  The species are in alphabetical order and include photographs of flowers, fruit, foliage (summer and fall in many cases) as well as overall habit.  Personal comments about plants in his Georgia garden are provided for the species that he grows - a plus for those of us that live in the South.

 Not a picture book, but a really cool reference is The Southern Gardener’s Book of Lists by Lois Trigg Chaplin.  This book covers Trees, Shrubs, Perennials, Annuals, Vines, Ferns, Groundcovers and more.  

The best part of this book is the organization: Trees for Wet Sites, Perennials that Bloom in Winter, Perennials for Heavy Clay Soil, Shrubs that do well in Deep Shade … list after list of problem solving ideas.  Not all plants are native, but you can use those ideas to research which ones ARE native.

Lobelia cardinalis seedling
What is more inspiring in winter than the thought of seedlings and new growth?   The carefully tended seeds in tiny peat pots under grow lights ... actually,  I mostly rely on Mother Nature - look at this little guy just poking his way through that clay soil!  It's a regular miracle that he made it.

One of my favorite books in this category is Making More Plants by Ken Druse.  Well organized, well written, good pictures … this book covers it all: sowing seeds, cuttings, layering, grafting, division and more.  

And for those of you that have all these books already, consider the latest native plant book for Southern folk: Best Native Plants for Southern Gardens by Gil Nelson.  There is hardly anyone more qualified than Gil to write this book.  It is a beautiful collection of plants, photographs, stories and ideas.

If you still want more ideas, peruse this reading list on the GNPS website. The list is divided into 4 categories (Native Plants, Restoration, Propagation, and Wildlife Gardening) or you can choose to print out the entire list.  If you are in need of gift ideas, it is a good place to start!

Magazines are also candidates for review during the winter.  During the other seasons, I flip through them quickly, not always reading each article, so going back to them in the winter is nice.  Some of the ones I like:

  • “The American Gardener”, the magazine of the American Horticultural Society comes only every other month and covers more than natives, but they have had some excellent articles on natives (including a two-part series by Gil Nelson on native hollies).

  • “Tipularia”, the annual journal of the Georgia Botanical Society arrives in December, just in time for winter reading!  You must be a member to receive this publication, but they sell back copies of it at meetings for $10 each.  Each journal contains 5-6 detailed articles about plants and plant-related topics.  It is worth the price of admission:

Sunday, December 5, 2010

You Don't Want This

We discover plants in many different ways: we might see an interesting one in a public garden, learn about it from a friend that grows it, read about it in magazine article, or just discover it growing somewhere.  Most of the time, the plant we discover is a great plant: attractive, robust, easy to grow, tolerant of adverse conditions or whatever attracted us to it.  Sometimes, however, you need to know that you don’t really want that plant.

A friend of mine that helps lead plant rescues for the native plant society occasionally comes across a plant growing wild that someone asks her to identify.  Marcia will look thoughtfully at it for a moment and then give the name if she remembers it.  Sometimes she does not remember, but she’ll give you her opinion of it anyway … and sometimes that opinion is “I don’t remember what it is but you don’t want it.”  She may even give it a made up name: “Weedy peskyosus”.  So I’d like to use this post to tell you about some plants that you don’t want so that when you come across them, hopefully you’ll remember to say “nevermind”.

Photo by:
Kerry Britton, USDA Forest Service,
The picture here is of Kudzu which certainly everyone in the South is familiar with now (and some folks up North are learning about it too!).  People have no trouble despising this as an “invasive” plant.  The plants which follow are only despised by those familiar with their abilities to spread into natural areas and roadsides.  These plants don’t spread as fast as Kudzu because they rely on birds, wind or water to spread their seeds.  They definitely spread, however, and the more they spread, the more seeds are available for them to spread even faster.

Nandina domestica is native to China and Japan and often known as "Heavenly Bamboo".  Bright clusters of berries and evergreen foliage help them get noticed.  Seriously invasive in warmer areas like south Georgia and Florida.  If you like bright red berries in the winter, consider the native Ilex verticillata instead.  The common name for this attractive native plant is “Winterberry”.

Mahonia bealei is native to China and, while it looks like a holly, is a member of the Barberry family.  For year this has been a “passalong plant” from someone that has it in their yard because seedlings come up on a regular basis.  Noticed by many for it’s evergreen foliage and blue berries, it is spread by birds to other areas nearby.  There is a species that is native to the Pacific Northwest; it is known as “Oregon grape”.  Do your part to control this plant by not accepting this “gift”.

Mimosa or Albizia julibrissin is the “pink powderpuff” tree so admired from roadsides throughout the southeastern US.  I will confess that when I first moved to Georgia in 1988, I was anxious to have one.  I convinced my husband to dig up one from the side of the road and plant it in our yard!  Oh, the shame of remembering that now! At some point we decided we didn’t want it and killed it (although the root sprouts plagued us for several years). Flowers are the only thing nice about this tree: it is late to leaf out, has no fall color and, of course, it outcompetes native plants in the areas that it invades.  Like the ferny look of the foliage?  Look into some of the native trees in the pea family: Locust, Yellowwood, Kentucky coffeetree, and Senna.

Ornamental pears – often known just generically as ‘Bradford’, Pyrus calleryana is spreading into roadsides of suburban areas thanks to the miracle of “cross pollination”.  These ornamental trees were bred to be sterile, but the introduction of other cultivars like ‘Cleveland Select’ and ‘Aristocrat’ have allowed even the older trees to produce viable fruit now.  In some cases the fruit is so large and prolific that people don’t even realize what these plants are (often also reverting to their natural thorny form) in the wild.  There are so many planted in suburban landscapes now that the production of fruit is becoming a real problem because wildlife (birds, squirrels, possums) is spreading it.  If you like a white flowered spring blooming tree, consider selecting a Serviceberry (Amelanchier) or Hawthorn (Crataegus).  We certainly don’t need any more pears!  I love this article by Jan Haldeman entitled Who Let the Pears Out?

Burning bush (Euonymus alatus) has long been popular in gardens north of Georgia and natural areas there are now full of this pest.  This shrub is gaining popularity in Georgia now – I see a lot of it in landscaped places like business parks and subdivision entrances.  I’m also seeing it pop up in nearby un-landscaped areas, thanks to the birds.  If you want bright fall foliage, look into native blueberries.  As a bonus, you get fruit in the summer as well!  Here is a blueberry is my yard.
Vaccinium sp., Blueberry
So back to the beginning – how we find plants.  I’d like to encourage you to research your plants so that you understand what you are planting.  You can do this in at least two ways. 

  • One way is to learn about a plant from a garden, a friend, an article and then research whether that plant is appropriate for you.  Use the scientific name if possible to make sure you get accurate data. 

  • The second way is to identify a “plant need” and then find a good candidate for that spot.  Perhaps you need a plant for a shady place, or a wet place or a plant to screen out your neighbor’s fence.

Researching plants helps you make the right choices by understanding the plant you’re getting (including any potential problems with it) and by ensuring that you are picking a plant that is suitable for the need (so that you get one that will thrive, not dive!).