Sunday, March 30, 2014

Nature Ramble

Early spring days are the sweetest when the sun is shining and the temperature is mild. Last Sunday was just such an occasion, and I had the opportunity to join a scheduled “nature ramble” through parts of the State Botanical Garden in Athens, GA. 

The trip was organized by the Georgia Botanical Society as one of their field trips, but the leaders of this trip ramble through SBG’s gardens on a regular basis (weekly it seems according to their blog).

Trillium decipiens
For this trip we started out in the Dunson Native Plant Garden along a lovely winding trail through a collection of ephemeral spring wildflowers. Although the wildflowers were planted by humans originally, they have moved and spread into new areas, creating pleasant drifts of color and texture. The garden has good signage although the squirrels have etched some embellishments on some of them.
Always exciting for me is to be able to see new plants. Trillium decipiens (known as the Chattahoochee trillium) is a sessile trillium with strong markings on the foliage. In areas where different species have mingled, it is noticeably different from Trillium cuneatum by way of a strong contrast on the leaves between the pale stripe on the center and the dark mottled sections.

Claytonia caroliniana

Next on the new list is the Carolina spring beauty (Claytonia caroliniana). I am more familiar with Claytonia virginica, Virginia spring beauty. While the blossoms are similar, the foliage is bolder on the Carolina species, and less grass-like. Neither species appears to be native to this county, but the plants appear very happy here.

We wound our way through the trail, enjoying the blooms of other trilliums, bloodroot and trout lilies. Soon we came upon toothwort (Cardamine), ragwort (Senecio) and liverwort (Hepatica). 

Dirca palustris
Among the leafy young buckeyes (Aesculus) we began to see a smallish shrub with bright green oval leaves and the remains of small yellow flowers. It was identified as leatherwood, Dirca palustris. The common name comes from the strong yet flexible property of its branches, used by Native Americans as a type of binding material.

Nearby were sweeps of Virginia bluebells (Mertensia virginica), lovely with a mixture of blue and pink flowers. A small population of Trillium persistens brought a story of why some folks call it “Edna’s trillium.”

Sanguinaria canadensis

Throughout the area, the crisp white petals of bloodroot (Sanguinaria canadensis) offered a delightful juxtaposition of fresh new growth against the dry, drab leaves of winter.

We continued to ramble through the different trails of the garden, identifying weeds and flowers alike as we went. Every plant had a story or its own tale to tell. Our trip through the Endangered Plant Garden found a huge stand of Alabama snow-wreath (Neviusia alabamensis) beginning to bloom. The delicate blooms and the endangered status seem at odds with the reports from people that have this in their garden. When it’s happy, you can be sure you’ll have plenty of this colonizing shrub to share.

Neviusia alabamensis

We moved on to the Heritage Garden where tall blooming paw paw trees (Asimina triloba) were admired for their unusual blooms. We were told that flies pollinate these flowers which smell like rotting meat, but our noses were apparently not attuned to that frequency. I could not detect any malodorous scent.

Asimina triloba

The garden was filled with old-fashioned (and non-native) ornamentals as well as a variety of fruit trees. A mason bee box was included to help support the bees that are so effective in the pollination of fruit trees.

We plunged back into the woods to complete our walk. Mayapple (Podophyllum peltatum), violets (Viola spp.) and Geranium maculatum were naturally scattered along the trail. As we paused, someone spotted a small orange butterfly. One of our leaders identified it as a Harvester butterfly (Feniseca tarquinius), a species that is right at home in this stream-lined deciduous woods. The caterpillars of this species are carnivorous, eating woolly aphids, scale insects and treehoppers. The adults feed on aphid honeydew, not flower nectar. What an amazing discovery on our ramble!

At the end of the day, the ramble was a delightful low-key way to reconnect with the natural world. From being outside, to admiring plants, to learning about new insects and creatures ... I can't imagine a better time.


Sunday, March 23, 2014

Snagging Birds

Birds are attracted to a variety of habitats: some like open areas (bluebirds, sparrows, robins), others like thick shrubs (brown thrashers, cardinals) and some like water. And some birds like dead trees (which are known as snags). Certainly we all know that woodpeckers like dead trees, but I was surprised to discover recently how many other birds use them too.

Last year a medium-sized pine tree next to the driveway died. It was far enough away from the house that we could allow it to stand and decay in place. This winter it has been alive with all sorts of birds. 

The first birds that I noticed using it were brown-headed nuthatches. Their high-pitched squeals caught my attention as I walked to the mailbox. I had never seen this species at my house before so I was excited to see them. They spent a long time there, moving up and down the peeling bark while looking for insects.

Next came a red-bellied woodpecker. Oh, the nuthatches were furious! They fussed and fussed at him but he would not budge. They had to be content with visiting it when he was not there.

When the snow came in January and February, the tree was more popular than ever. Small birds like chickadees and wrens made quick visits to look for bugs. In between, the woodpecker and the nuthatches would stop by. This tree was clearly in their round of trees to visit once the sun came out and warmed up the bark (and the bugs beneath it).

One day I even discovered a pileated woodpecker working the lower portion of the tree. Unfortunately he saw me about the time I saw him and he took off quickly to find a more private meal.

Consider yourself lucky if you find a dead tree nearby (and you can leave it there safely). Then get out your binoculars and start watching it. You just might find yourself snagging some pretty interesting birds! By the way, this goes for dead trees on the ground too.

Sunday, March 16, 2014

A Plague of Pears

This is the time of year when I am reminded that callery pears (Pyrus calleryana) are an invasive plant in the southeastern US. For most of the year the pears are not noticeable from a distance and my memory slips. Come spring, however, their stinky white blooms open up earlier than almost any native tree (red maples have them beat), revealing every nook and cranny that they have managed to occupy.

I don't have to go far to find an example like this

Some folks might kindly think that someone planted the pear tree on the edge of the woods or in that vacant lot. Probably not. Roadsides and waste lots are showing more and more signs of invasion. I pull them out of my yard on a regular basis because of trees in the neighborhood. I see them growing on the edge of my neighbors' yards, unrecognized for the invader that they are.

How did this happen? Ornamental pears are native to southeast Asia; as the common name implies, the fruits are small and not considered edible by most humans (although they probably could be eaten). The cultivar 'Bradford' was created as a self-sterile ornamental tree that would not create even those small fruits.

Then 'Bradford' was discovered to have weak branching, causing it to split in storms (and sometimes even without a storm). Nurserymen developed new cultivars like 'Aristocrat' and 'Cleveland Select.' Unfortunately, cross-pollination was now possible between the cultivars, allowing ALL the trees to produce small but viable fruits. Trees that were previously sterile would now produce fruit if a different cultivar was within range.

Fruit on Pyrus calleryana

Wildlife such as birds and squirrels help spread these fruits, allowing new plants to grow in wild and un-managed areas. The vigor of these seedlings allows them to grow fast, out-competing other plants and creating dense thickets over time. The seedlings are sometimes thorny, a characteristic of the original species that was bred out of the cultivars being sold.

I applaud communities like Columbia, Missouri that are helping to make its citizens aware of what is happening. Too often people just let "nature take its course." I encourage you to look out for strange plants popping up in your yard. Pear seedlings usually have a notch in the leaf and turn bright red in the fall. Please pull up and discard any that you find. There are far better things to cultivate.

Notice the notch in the leaf on the lower left side

For more pictures to help you identify this weedy tree, please see my earlier post on this.

Sunday, March 9, 2014

Native Plants for Butterfly and Pollinator Gardens

When it comes to native plants supporting pollinators, nectar content is extremely important. The quality and quantity of nectar is what feeds pollinators like butterflies, bees, wasps, certain flies and even birds and bats. I want to make you aware of two other components to native plants that also support these guys: pollen and foliage.

Monarchs look for nectar in Sept/Oct in Georgia (on Solidago)
It is important to consider all 3 when you decide what plants to choose to support pollinators and even butterflies specifically. We all know what nectar is, so here is a little background on why pollen and foliage are important and why you should consider them when choosing plants to include.

Pollen is the dusty yellow stuff that we all know so well from plants that give it up in abundance to support pollination by wind (oaks, pines, mulberries, grasses, ragweed). Insect pollinated plants have heavy pollen that is not wind-blown. These plants have attractive flowers designed to convince insects to stop by and have a snack (or at least have a look). While the insects are browsing they are also providing pollination services by dragging pollen from one flower to another or from stamen to pistil in the same flower.

Bees love Agastache
Pollen is actually nourishing itself and many insects eat pollen or feed pollen to their young. Bee bread is a mixture of pollen and nectar that bees create for their young to eat. Some adult insects eat both nectar and pollen themselves. So if you want to support bees, look for plants that have good sources of pollen.

Foliage is another part of a native plant that is important to insects such as Lepidoptera, the order of butterflies and moths. Some insects do not eat as adults (they don’t even have mouth parts), but all insects have to eat in their larval form. Butterflies and moths lay eggs on the leaves of plants that they can eat. These plants are known as their host plants. So if you want to support butterflies, look for plants that have host relationships.

American lady caterpillar on Antennaria

Some species have multiple hosts and some species host on a single genera. For example, the eastern tiger swallowtail butterfly can lay eggs on wild cherry (Prunus), sweetbay (Magnolia), basswood (Tilia), tulip tree (Liriodendron), birch (Betula), ash (Fraxinus), willow (Salix) and others.

In contrast, monarch butterflies can only lay eggs on milkweed plants (Asclepias spp.). If you want to support the full life cycle of a particular butterfly or moth, foliage plants must be considered.

American lady butterfly - all grown up! On Stokesia flowers.

So this is all to say that when you are planning a butterfly or pollinator garden, consider these 3 aspects: nectar, pollen, foliage. A fourth consideration is bloom sequence. Some flower should be in bloom all the time, especially if you are supporting bees. 

So here is the meat of this post. I have created 3 documents to list a selection of Georgia native plants and indicate what insects they support (and how) and to also note approximately when they bloom in the metro Atlanta area. Click on the links to load the documents (which are printable):

Proper selection and planning will ensure that butterflies and pollinators that stop by will have nectar and pollen available to them throughout the warm seasons. Consider also that you may want to support certain periods like the monarch migration which happens in Georgia around mid-September to early October. Flowers like goldenrod (Solidago), blazing star (Liatris) and boneset (Eupatorium and relatives) are good nectar providers during that time.

It's that time of the year that spring plant sales pop up (thank goodness). So get your lists ready and go shopping! Don't forget my favorite sale - Georgia Native Plant Society on Saturday, April 12th. Come see us!

References for insect information in my documents:

Illinois Wildflowers (they have great faunal association descriptions)