Sunday, March 1, 2015

A Perfect Plant for Birds in Georgia

Finding the perfect plant for gardeners who want to support birds would be a wonderful thing. Every bird lover would rush to purchase such a plant. Time to be amazed: such a plant exists and is native throughout Georgia. The plant is black cherry (Prunus serotina) - pronounced PROO-nus sair-OTT-ih-nuh - and it is found from far northern Georgia to the very southernmost counties. From east to west and north to south, black cherry thrives in the varied soils and climate of Georgia.

Black cherry (Prunus serotina) in bloom

Knowing what birds eat is the key to understanding why this plant, and its close native relatives, is such an ideal plant. Here is a quick review of the diet of adult birds. Adult birds, you see, are rather specific eaters.

Female red-bellied woodpecker on suet
Those adults that eat seed will flock to your seed feeders: cardinals, goldfinches, pine siskins, sparrows and finches of all kinds. You’ll also get birds like mourning doves, titmice, chickadees, bluejays and the occasional woodpecker. If you have some suet feeders, especially in winter, then you’ll bring in birds like warblers, wrens, bluebirds, and more woodpeckers that need some high energy food. Cold temps and snow cover will encourage even more species to stop by for a winter bite.

The plump fruits of black cherry 

In the spring and summer, birds focus more on their traditional adult diet and that’s where black cherry really shines. Birds that are frugivores (fruit is a large part of their diet) thrive on the small fruits of the native cherry trees, and as many as 53 different species of birds have been observed eating them (not all of them frugivores). These include birds like cedar waxwings, mockingbirds, catbirds and tanagers. Other wildlife eat the fruit too.

While adult diet is very important, we need also consider the diet of baby birds. That’s where the foliage of black cherry is important. A large percent of baby birds are raised on insects – 96% of bird species feed insects to their chicks. It takes an enormous amount of insects to feed just one clutch: an estimated 6000 to 9000 insects for a nest of chickadees and those are small birds.

Caterpillar of Furcula borealis on black cherry
While some of those insects are spiders and other things, most of them are caterpillars. Birds find caterpillars on the leaves of plants, primarily native plants. As most of you know, caterpillars are the larval form of butterflies and moths. Our native butterflies and moths have host plant relationships (think monarch butterfly and milkweed) with the plants they evolved with. Watch an entomologist explain it better in this short video.

Black cherry happens to be a host plant for over 450 different species of butterflies and moths. Species include those as familiar and beautiful as the Red-spotted Purple, the Viceroy, the American Lady, the Cecropia silkmoth, the Coral Hairstreak, and our state butterfly, the Eastern Tiger Swallowtail.

Of course there are still many more species, some of them drab colored moths (see White Furcula moth pictured) that we don’t notice. These make up the bulk of the caterpillar population that feeds these birds; they are most of the 6000-9000 insects that are needed to raise just one set of baby birds.

The yellow-rumped warbler eats insects in the spring and summer
You'll also be supporting the many adult birds that rely on an insect diet. Birds that are insectivores include the warblers, flycatchers like the Eastern phoebe, bluebirds, wrens, robins and our state bird, the brown thrasher.

The flowers of black cherry are numerous and attract a wide variety of pollinating insects, especially native bees of several types. If you like to support native bees, you now have another reason to want black cherry in your landscape.

All in all, black cherry has extremely high wildlife value. If you only want to have it for the birds, that reason is plenty is good enough. All the other critters will enjoy the fringe benefits.

Sunday, February 22, 2015

The Solution to Fewer Native Plants is Fewer Native Plants?

Recently someone on a message board was advocating that we respond to the decline in native plants by planting more non-native plants. The issue in question was having fewer nectar sources for butterflies due to habitat destruction and development of wild lands into subdivisions, shopping areas and commercial real estate.

This is not the first time that I've seen someone advocate using non-native plants specifically because there are fewer native nectar sources than before. It implies a “we can make nature better” mindset.

This approach demonstrates a lack of understanding in regards to insect life cycle, a lack that was all the more startling given that it was being demonstrated by someone that was arguing on behalf of the monarch butterfly. The monarch butterfly is THE “poster butterfly” for the larval-host plant relationship. Monarchs need milkweed (Asclepias spp.) to lay their eggs on, right? Without milkweed plants, monarch butterflies cannot survive and the last two years have dramatically demonstrated that.

One cannot focus only on nectar plants - nectar is only used by the adults. The needs of the larvae are completely different from the adults. By advocating that non-native plants be used for nectar instead of the nectar-producing natives that disappeared, this person is saying that some butterflies and moths are more worthy than others.

This wingstem (Verbesina alternifolia) supports bees, provides nectar, and  is a host plant

You see, the rest of the native Lepidoptera (butterflies and moths) in North America have similar relationships with their own host plants just like monarchs and milkweed and they need those plants to be available as well. Goldenrod (Solidago spp.) is a top native late summer nectar plant and host to well over 100 different species of butterflies and moths. Here is a short list of some of those special relationships:

  • Silvery Checkerspot (Chlosyne nycteis): host plants include native sunflowers (Helianthus spp.) and common wingstem/crownbeard (Verbesina spp.).
  • Gulf Fritillary (Agraulis vanillae) and Zebra Longwing (Heliconius charithonia vazquezae): both of these lay eggs only on members of the passionvine (Passiflora spp.).
  • Great Spangled Fritillary (Speyeria cybele): host plant is violet genus only (Viola spp.).
  • Zebra Swallowtail (Eurytides marcellus): host plant is only paw paw (Asimina spp.)
  • Great Purple Hairstreak (Atlides halesus): Mistletoe (Phoradendron tomentosum).
  • Henry's Elfin (Callophrys henrici): Redbud (Cercis canadensis).
  • American Lady (Vanessa virginiensis): host plants include cudweed (Gnaphalium) and pussytoes (Antennaria).
  • Cloudless Sulphur (Phoebis sennae) and Sleepy Orange (Abaeis nicippe): both host on what most people might consider weedy legume plants like partridge pea (Chamaecrista fasciculata) and sickle-pod (Senna obtusifolia).
  • Coral Hairstreak (Satyrium titus): Sandhill plum (Prunus angustifolia), and black cherry (Prunus serotina).
  • Spicebush Swallowtail (Papilio troilus): hosts on spicebush (Lindera benzoin), sassafras (Sassafras albidum), tuliptree (Liriodendron tulipifera).
Some Lepidoptera are even named for their host relationships: Hackberry Emperor (Asterocampa celtis) hosts on hackberry (Celtis spp.), the Yucca Giant Skipper (Megathymus yuccae) hosts on Yucca, and Pipevine Swallowtail (Battus philenor) hosts on pipevine (Aristolochia).

This Red Admiral butterfly hosts on stinging nettles

There are some species that have evolved relationships with more than one host such as the Painted Lady (Vanessa cardui) and Common Buckeye (Junonia coenia). Those butterflies have choices, but still they are hosting on native plants, not crape myrtle, not ligustrum, not forsythia or knock-out roses and definitely not on butterfly bush (Buddleja).

While this Zebra Longwing happily nectars on Lantana, there won't be any new ones
unless you have passionvine (Passiflora)

"What about Black Swallowtail butterflies?", you say. They lay their eggs on parsley and fennel, two non-native herbs that are frequently used in "butterfly" gardens. The scientific answer is that both parsley and fennel are in the Apiaceae family which is the same family that contains the native host plants for this butterfly. These same butterflies would naturally host on plants like golden Alexander (Zizia aurea) and any species of Angelica as well as many other native members of the Apiaceae family. Black Swallowtails benefit from this close chemical similarity in plants.

Golden Alexander (Zizia aurea) hosts Black Swallowtail butterflies

For the vast majority of Lepidoptera, however, when you choose to use non-native plants for nectar, you are depriving another Lepidoptera of its host plant. I’m not suggesting this is always a big deal, especially when done in moderation and in consideration of 3 things: quantity, quality and invasive tendencies:

Quantity: having relatively few non-native plants while having mostly native plants is the best approach.
Quality: choosing non-native plants that have abundant nectar and pollen gives you the most bang for the space.
Invasive tendencies: avoiding non-native plants that have invasive tendencies in your area is important.

I will plant a few non-native nectar sources this year, but I'll be mindful of those 3 considerations when I make my choices. We can help some butterflies without hurting others if we make informed choices. 

Nature has already set these relationships between plants and Lepidoptera. We can't change them and we can't make nature "better." We can understand them and we can help to keep them going. That's why we have the big brains.

Sunday, February 15, 2015

Avoid the 'Noids in 2015

This subject is on my mind way too often, but I don’t want to be the only one thinking about it. We all need to be concerned and educated when it comes time to choose our plants this spring.

I’m talking about neonicotinoids (NEO-nik-oh-teh-noids). Neonicotinoids are a type of pesticide that has been widely touted in the last few years as a “safer” type of pesticide against sap-sucking and leaf-chewing insects because it is taken up by the plant through the roots (it is watered in or applied to the seed as a pre-treatment) and doesn’t involve the hazards to humans from treatments like spraying.

These pesticides have been found to not be “safe” for insects that eat or gather pollen and nectar from the treated plants because there are residual amounts of the chemical in the pollen and nectar. That means we don't want these chemicals applied to any plants that require insect pollination (like our fruits and vegetables) or the plants that we use to attract and sustain butterflies.

Neonicotinoids are now considered a likely contributor to problems with bees, problems as serious as killing them outright or at least causing disorientation such that they cannot find their way back to their hives (in the case of European honey bees) or their nests (in the case of native bees). Bees leave the hive or nest to gather pollen and nectar to bring back. Along the way, they will eat some of what they gather for their own nourishment.

Frankly if they cannot find their way back to the hive or nest, they are as good as dead anyway because they are not helping the next generation of bees.  

So what's a conscientious gardener to do? Both plants and seeds need to be considered. One approach is to pre-research everything. A blogger on the West Coast has put together a fabulous collection of information on many of the large growers and seed providers. She contacted them and has published their responses. 

Gardeners who are concerned about purchasing products treated with neonicotinoids have asked for companies to label their plants so that treated plants can be avoided. The Home Depot announced last year that they would require their suppliers to let them know about treatments so that they could label the plants. Bravo! I'm not aware of any other major plant retailer in Georgia that has agreed to provide labeling.

Blueberries treated with neonics

The new labels have now arrived at Home Depot and I thought I'd take a field trip to see how plants and seeds are being labeled there. What is clear is that the labeling on plants is being used to definitely indicate which plants have been treated. Plants that are not labeled can - I assume - be considered as not having been treated by neonics. 

Or the label fell out. Or that pot was missed. You might have to search around to see if other plants (same kind of plant) in the area have tags and the one you picked up was just not labeled. You can see here that the label is just tucked into the pot, and sometimes it is shoved all the way to the soil line.

Here is a picture of the label and it looks like they are probably being applied at the store once the plants are delivered (in other words, it is Home Depot's tag, not the grower's tag). 

I examined all the seed packets at Home Depot and none of them are labeled for neonicotinoids. Several have "non-GMO" labels but that is not the same thing. One package was labeled as "organic" but I am not sure that is a guarantee.

This package happens to be from Ferry-Morse which is not using neonics according to the blog on referenced earlier. It would be more clear if they'd say that.

Non-GMO does not mean no neonics
Does organic mean no neonics?

You also need to consider the pesticide products that are sold for use in the home garden. Look at the labels. Neonicotinoids include chemicals like imidacloprid, clothianidin, thiamethoxam, acetamiprid, and dinotefuran so look for these on the labels. The Xerces Society has a great page about products that are available for home use and which ones should be avoided by consumers.

So if protecting pollinators (bees, butterflies, etc.) is important to you, start reading labels - plant labels and package labels. If you're not sure, ask at the store. Retailers won't realize it is important to us unless we speak up.

Sunday, February 8, 2015

Awaiting the Turn from Brown to Green

American beech (Fagus grandifolia)
As we move into February, warmish and sunny days tease our senses. We long for spring, but these are some of the brownest days of all. 

Perennial stems, once tall and straight even in death, have collapsed under the rains and cold nights. Their ragged, soggy limbs lie crumpled against the withered leaves of fall.

Sparkling rays of sunshine fall on empty seed capsules, highlighting their vacant vessels. Their job is done and their emptiness has a beauty of its own. After all, the capsule is a testament to their fertility.

Hibiscus coccineus capsule

Among the brown, in Georgia, there are spots of green. They are plants that never really go away; they are just dozing in the sunshine. I’m sure they are gathering energy; I've never known nature to let good stuff go to waste.  

A Christmas fern (Polystichum acrostichoides) here, an ebony spleenwort (Asplenium platyneuron) there … plus a scattered assortment of perennial herbs like green and gold (Chrysogonum virginianum) and the leafy rosettes of cardinal flower (Lobelia cardinalis).  

Tiny Christmas fern in the grass

I am glad to have the green, but by now I yearn for more than that. I want flowers. I want flowers, not just for themselves but for the rest of life that they bring. With flowers come insects: bees, butterflies, moths and caterpillars. Even flies (flower flies, that is) would be welcome. With insects come birds in abundance. The whole place comes alive!

A few more brown days I must endure. Nature comes in her own time, but … I just saw a single trout lily leaf (Erythronium umbilicatum) poking through the pine straw. The end of brown is near.

Sunday, February 1, 2015

A Native Tree Is Not Just A Tree

It’s an ecosystem. It is more than just a collection of leaves, flowers and fruit. It is more than just a giver of shade and large limbs for swings. It is a home and giver of life to more than we even know.

Years ago we all learned that trees are an important source of oxygen. They take in carbon dioxide that we breathe out and give us oxygen in return. They also help clean pollution from the air. Learning this was like learning about magic. What an easy thing to do! We were all excited about planting trees to improve the Earth.

People went about happily choosing and planting trees. They planted them in their yards and in their schools. City parks and median strips were strewn with these oxygen machines. It was a glorious time. Nurserymen found exciting new choices to offer their customers - exotic plants from around the world. In my childhood city, crepe myrtles were all the rage and the city planted them everywhere.

New oak leaves ready to support insects
A few people knew that not all choices were equal. You see these places where we were planting our new trees were once home to forests of indigenous trees. Oaks, maples, hickories, and chestnut once ruled the land. Their foliage and flowers were the food and sustenance for thousands of native insects.

Native plants evolved with the native insects and scientists find more evidence every year that those insects largely can’t live on non-native plants. Now you might think that fewer insects is a good thing … until I remind you that butterflies are those insects. Remember the monarch butterfly that eats only milkweed (Asclepias) plants? When milkweed goes away so do those beautiful butterflies. 

Bird food!

Every plant species has an insect or two - or even 534 of them – that depends on them.

The mighty oaks that once lived here in vast tracts support 534 different species of moths and butterflies … that we know about. There may be more. 

Birds are very fond of those insects. Many birds eat insects as part of their diet. Many more feed them to their babies. I read a great article recently about research on a common backyard bird and its relationship to suburban/urban landscapes. From the article:

Contrary to what many people believe, “birds do not reproduce on berries and seeds,” Tallamy says. “Ninety-six percent of terrestrial birds rear their young on insects.” Because native insects did not evolve with nonnative plants, most lack the ability to overcome the plants’ chemical defenses and cannot eat them.

When we're choosing our trees, most of our trees, we need to consider not just our desires but the needs of the rest of our local world. We can choose trees that feed the local insects who in turn feed the local birds. The tree's fruit (or nuts) might also feed local mammals, and of course everything might become prey for the next member of the food chain.

It's a choice that we can all make, right in our yards and in community projects, and it has an immediate positive benefit. From the moment you plant it, the benefits begin for the insects.

By the way, I am glad to hear that my childhood city is changing. I read recently that the city is gradually replacing those crepe myrtles with other species, such as maple, dogwood, crabapple or sweet bay, in an effort to diversify its tree selection. The reasoning given was to reduce disease potential as well to incorporate more native species.

We all can learn again not just that trees are important but their importance is MORE than just oxygen and shade. Their role in the insect world is every bit as important. Arbor Day is coming up this month in Georgia; this year think about planting a native tree.  

Sunday, January 25, 2015

That Wild Land

You see it from the road, just beyond the guardrail or along the edge where the pavement ends. It’s where the deer dashes after he got too close to the road and the cars came roaring by. As you pass it in the car, there seems to be no sign of life. There is just an indistinguishable forest of trees: bare in the winter, green in the summer, and yellow/orange/red in the fall.

On the bridge over the Etowah River near me, hundreds and thousands of bare trees stand in apparent silence as we drive over and look down for a glimpse of the dark water.  Again, there is no sign of life.  I wonder how many people even notice it or, if they do, think about how that land should be “cleaned up.”

Ruby-crowned kinglet in the woods
I know these places teem with life. Exit your car and get into the woods and the songs of the birds will fill your ears. They are on an all-day search for food, either for themselves or to feed their chicks. They live in these woods.

Along with them live a hundred other creatures: squirrels, snakes, mice, chipmunks, lizards, bats, foxes and many more. Each of them searches these woods for food, a mate and a place to live.

As if supporting animal life were not important enough, these wild areas have another function. They help to filter pollution, both air and water. While all land filters water to some extent, these broad and deep areas of rich soil filter water pollution even better than the compacted and disturbed area we call “lawn” The complex ecosystems that live beneath rich soil have a whole community of critters, fungi and minerals that gets the job done right.

Areas that are adjacent to small streams play a crucial role in delivering clean water into our rivers. Yesterday I took these pictures along Scott Mill Creek, a small but swift stream that later joins Canton Creek before it folds into the Etowah River. The Etowah River is home to 76 species of native fish and is a source of drinking water for many people in the area. It's water we want to be clean!

I passed a sign yesterday in front of a broad, wooded expanse of land. It said “Available” and I laughed. I imagine all those critters living there would disagree.

Sunday, January 18, 2015

Ground Zero

When it comes to plants, the ground is the beginning. That is where the seed takes root and begins its journey of growth.  So much happens at the ground level and being able to watch it during the winter is pleasure for those of us in Georgia. That’s because we rarely get snow in Georgia. Even when we get snow, it doesn’t stay around for very long because the ground is warm and the temperature is often above freezing.

A warm ground means that not only are seedlings able to grow, but all the critters that live in the soil can still be active. Here in north Georgia we can turn the soil in January and find wriggling earthworms and active centipedes. Mushrooms are abundant in the winter months thanks to ample rain.

Our year-round birds like the Eastern towhee and the brown thrasher actively hunt among the leaves for their meal of choice: bugs. American robins and Carolina wrens are avid insect eaters as well and seem to find enough to keep them fed during the winter.

Brown thrasher, looking for bugs

Turtlehead seeds (Chelone glabra)

Most perennial plants are dormant and have disappeared from view, leaving only the tattered, wispy remains of their summer foliage and some seed heads. At ground level, close to the residual warmth of the soil, some plants remain green and vibrant.

Thank goodness for the lack of snow – we can enjoy the green leaves of plants like cranefly orchid (Tipularia discolor), rattlesnake plantain (Goodyera pubescens), galax (Galax urceolata), ginger (Hexastylis arifolia) and groundcedar (Lycopodium spp.).

Winter-bronzed leaves of Galax

Instead of snow we get rain – long, deep soakings that recharge the ground moisture and prepare the plants for spring growth. On the edge of the woods, the leaves from the deciduous trees are already breaking down. The rain and the warmth of the winter days have paired up with small insects to turn those leaves into black gold, a source of nourishment to the roots that wait below.

Fungi threads

Scratch below the surface to find tiny rootlets intertwined with mycorrhizal fungi, thin strands of a white highway that transports nutrients to connected plants. Nearby might be an acorn, its thick root thriving and growing even now, plunging deep into this rich ground, perhaps making its fungi connections already.

Ground zero – it all starts here.