Sunday, August 30, 2015

Seeds: The Next Generation

The blooming season is in the last quarter now and plants are busy making or ripening their seeds. Some seeds, like those encased in the fleshy fruits of spring plants such as plums and cherries, are long gone, gobbled up by hungry critters. Other seeds take a long time to form. For example, acorns on oak trees in the red oak group are ready in the second fall after they were fertilized and witch hazel (Hamamelis) seeds are ripe when the flowers bloom the next year. Other plants, particularly annuals and perennials, are ripening and dropping seeds throughout the season.

Milkweed seed gets ready to fly

Now is a good time to keep an eye out for ripening seeds that you might have wanted to collect. I keep a list for myself so that I can remember what I wanted to gather. 

Seeds are a particularly fun topic to help kids learn more about the natural world. After all, seeds are the next plant generation just like kids are the next human generation.

I’m currently reading The Triumph of Seeds: How Grains, Nuts, Kernels, Pulses, and Pips Conquered the Plant Kingdom and Shaped Human History by Thor Hanson. The author offers some fascinating information about these things which are, in essence, “baby plants in a box with their lunch.” Why are some seeds so big and others so small, don't they all need the same thing?

Impatiens capensis flower

With seeds on my mind, I noticed some particular seeds this week. I saw the summer blooming jewelweed (Impatiens capensis) which makes its seed pretty quickly and then disperses it at the slightest touch. 

In fact, it’s called “touch me not” because the seed capsule shatters when touched. It's a fun seed to share with kids.

Impatiens seed in pod
Impatiens pod after exploding

Silphium seeds are the dark spots

There are seeds that ripen but stay hidden until just the right birds come along to pry them out. Sunflowers (Helianthus) and rosinweeds (Silphium) are such plants.

The seeds are actually large enough for young hands to explore as you take a flower head, pull it apart a bit and point out where the seeds are hidden. The large plants are sturdy enough to hold the weight of the goldfinches that seek out the seeds.

Sanicula canadensis seed under microscope
Some plants have seeds with tiny hooks on them so that they attach to the fur of animals and the clothes of humans who pass by. This mechanism helps the seeds be dispersed over a greater area. You can use a magnifying glass to see them up close.

Other special considerations might affect how a seed is packaged. The overcup acorn (Quercus lyrata) has a larger than usual cap which acts as a floatation device. These oaks naturally live near river floodplains and poorly drained bottomlands so the ability to float is probably helpful. Maples and other trees have wings on their seeds to help them disperse. Milkweeds and dandelions have little bit of fluff attached. All these parts are not the seed itself but rather extra packaging.

Blueberry fruit with tiny seeds
Some seeds are meant to be eaten so that stomach acid and traveling by the organism that ate it provide two services: scarification and distance of dispersal (when the eater poops, of course). 

Blueberries are a fleshy fruit that contain many tiny seeds. The seeds are small enough that the eater doesn't mind eating them. Kids might be interested to know that, by eating seeds, they are doing just what the plant wants! The tasty fruit is the plant's reward to us.

Passiflora lutea seed under microscope

Still other seeds have intricate designs if you examine them up close. Surely there must be a purpose!

Next time you come across a seed, take a moment to appreciate and be curious about how and why it is what it is. And if you’ve got a young human nearby, take the opportunity to spark their curiosity too.

Sunday, August 23, 2015

Some For You and Some For Me

I like to think of myself as a “habitat gardener.”  I cultivate a garden to be a habitat for as much wildlife as possible. While I don’t pretend to support larger forms of wildlife (bear, deer, fox), I hope that insects, birds and assorted small creatures might find this area to be a place of shelter and nourishment. An important realization of being a habitat gardener is that things will eat your plants.

Cardinal flower - one plant eaten, others forming flowers

In fact, that is a key component of how I judge the success of my garden. In addition to the sounds of birds, frogs and insects, I look for visual clues:

-          A butterfly floating among the flowers, sipping nectar from their colorful blooms
-          A bee busily gathering nectar and pollen, pollen dusting her body or packed onto her legs
-          A caterpillar munching a leaf, growing long and fat on its way to becoming a butterfly or moth

That’s right, an insect eating my plant is a sign of success for me. Each one I find earns a little “Woo hoo!” from me. I know that we can’t have beautiful butterflies and moths without losing a little foliage along the way. When I’m growing plants, I consciously plant some for the insects and some for me.
Sometimes it's just one

Sometimes it's a lot

And it usually works out just fine. The insects eat some of what I grow – often not all the leaves on one plant and certainly they don’t eat all the plants. Frankly the deer are more of a challenge, but that’s another story.

Let’s not forget the birds – they are benefiting too and not necessarily in the way you might think. I do have some plants with berries, but that’s not what they want the most. They want the insects! By attracting insects, especially insects that eat foliage, I am also feeding the birds.

Wren with a caterpillar found on the Lobelia

"Grow caterpillars for us!"
There are a lot of birds that are insectivores and even those that aren’t insectivores will gather insects to feed their young chicks. 96% of birds feed insects to their babies, including hummingbirds (did you wonder what purpose mosquitos serve?).

Therefore, some of the caterpillars eating my leaves are destined to be food for someone else.

So the next time you’re planting, think of the insects (and the birds) and consider planting “some for you and some for me.” I guarantee you’ll enjoy the outcome a little bit more.

Sunday, August 16, 2015

Who Are You Calling A Weed?

Dozens of plants across Georgia are asking that question of the humans that have proclaimed them to be weeds. Even plants can recognize when they are being dissed. Most notably upset are the plants who have come to be known by the name “weed.” These include plants like:

Milkweed (Asclepias), Joe pye weed (Eutrochium), Pokeweed (Phytolacca), Jewelweed (Impatiens), Sneezeweed (Helenium), Thimbleweed (Anemone), Gopherweed (Baptisia), Smartweed (Polygonum), Pickerelweed (Pontederia), Knapweed (Centaurea), Chickweed (Stellaria), Cudweed (Gnaphalium), Ironweed (Vernonia), Camphorweed (Pluchea and Heterotheca), Hawkweed (Hieracium), Rosinweed (Silphium) and many, many others.

Gulf fritillary butterfly on orange milkweed

Even those lucky enough to escape the weed name are frowned upon as weedy, undesirable plants:

Goldenrod (Solidago), Thoroughwort (Eupatorium), Fleabane (Erigeron), Sedge (Carex), Broomsedge (Andropogon) and most native grasses, Thistle (Cirsium), Old-field aster (Symphyotrichum), Common Violet (Viola) and more.

While man may call these weeds, many insects could not live without them in Georgia. These durable, tolerant and prolific plants provide essential services to our native bees, butterflies, beetles and many other insects.

In some cases, the blooms provide nectar and pollen for visiting insects. Spring roadsides are full of the tiny white flowers of daisy fleabane while thoroughwort and goldenrod are rich nectar sources in the later summer and fall.

Red-spotted purple caterpillar on native hawthorn
Yet as essential as the blooms are for some insects, it’s the leaves that really matter to hundreds more. Native plants are host plants to native butterflies and many of these “weeds” are the most supportive ones. (Host plants: Adults butterflies lay their eggs on these plants and caterpillars grow up on them.)

Goldenrod foliage is host to more butterflies and moths than any other native (or non-native) perennial. Those roadsides full of tiny white asters – those asters are the #2 foliage plant. Thoroughwort is number 4 and together those plants are host to almost 200 types of butterflies and moths. These “weeds” are powerhouses of life!

The adult red-spotted purple butterfly - quite a transformation
You might come across these caterpillars in your garden, but chances are you will miss seeing most of them. Because birds want to eat caterpillars, caterpillars have learned how to hide themselves very well. Some eat only at night, others hide under leaves or mimic something else (like the color of the leaf, or a stick, or even as bird poop!).

Those that survive will emerge as the beautiful butterflies and moths that we recognize.

Milkweed is a fairly well-known host plant for the Monarch butterfly and 11 other butterflies and moths. In fact, nurseries could hardly keep milkweed in stock last year after people heard about the decline in the monarch populations. Many other butterflies have similar special host plant relationships.

Did you know that sedges support 3 times as many butterflies and moths and violets over twice as many as milkweed? Yet both sedges and violets cause most homeowners to reach for the herbicide. Don’t think of these as weeds – think of them as butterfly host plants!

A familiar butterfly is the silver-spotted skipper; it is a very reliable visitor and said to be one of the most recognized skippers. But you've got to have some native legumes if you want to have more of these. Here is the caterpillar all wrapped up in the leaf of its host plant, Clitoria mariana, known as Atlantic pigeonwings.

Silver-spotted skipper caterpillar
Silver-spotted skipper adults

So the next time you are deciding what to use or what to keep in your landscape, spare a thought for these plants. You don’t need a yardful of “weeds” or violets, but leaving a few here and there will be very beneficial to those that search for them.

Sunday, August 9, 2015

Butterflies and Blooms

I love a good success story when it comes to helping our natural communities, and this week I had a chance to visit one. Last year, I learned about an effort in Eatonton, GA to create a place that would support butterflies in abundance. The person spearheading the effort wanted to know how to find more larval host plants for native butterflies. Well, you don’t have to ask me twice about how to find and use more native plants!

Last year I watched this project (known as “Butterflies & Blooms in the Briar Patch”) grow and literally blossom as picture after picture of gorgeous Georgia butterflies were shared on their Facebook page. Come spring of this year, the group of dedicated volunteers hosted a plant sale featuring native host plants and nectar sources. Their “patch” in an old field was growing bigger by the workday as volunteers carved out paths, created beds and built arbors that give rest to humans and support to native vines.

When I stopped by on Saturday, August 8th, the patch was buzzing with insect activity. Butterflies and skippers floated and hopped from bloom to bloom. Bees were there too, gathering pollen and sipping nectar. The more I looked, the more insects I found: grasshoppers, beetles, cicadas, robber flies, dragonflies, wasps, and spiders were all there.  I circled the patch again and again, amazed at the diversity of insects. This project set out to support butterflies and moths (Lepidoptera) and ended up netting a bigger chunk of the ecosystem.
Black swallowtail

Eastern tiger swallowtail

Pipevine swallowtail

A closer look with the help of the chief volunteer, Virginia, revealed the importance of the host plants that were tucked among the nectar plants. Caterpillars were spotted on the spicebush (Lindera benzoin), the maypop (Passiflora incarnata), the wafer ash (Ptelea trifoliata), and herbs like parsley, fennel and rue. Monarch butterflies are just now arriving and milkweed awaits them. Caterpillars can be hard to spot – they don’t want any birds to find them! – so you can be sure there are many more caterpillars hiding in host plants then what we saw.

Giant swallowtail laying egg on rue

Giant swallowtails on Ptelea trifoliata leaves

For the curious visitor, excellent signage is there. Several large signs explain Lepidoptera life cycles.

A 4-page color Habitat Guide is available to take home. It includes a list of butterfly larval host plants for the butterflies that have come to the patch.

A map outlines where to find some of the host plants that have either been planted or documented as already existing on the property.

The patch will continue to grow. A large area of non-native grasses will be transformed this fall into a native prairie meadow. The list of native plants to purchase and acquire is already defined for the project. The plants being added will support even more species of butterflies and moths as both host and nectar plants.

Buckeye butterflies on rue

Bee on Ratibida columnifera

The volunteers come regularly to weed, water and observe the success of their efforts. The project is an amazing success story both as an educational effort and the insect life that it supports. The volunteers have educated themselves in the process as well as inspired countless new people to appreciate and support our native insects by using native host plants. Bravo!

Note: I would love to see more volunteer groups turn patches of unused sunny property into butterfly and insect habitat.This inspiring project deserves to be replicated in communities throughout Georgia and the rest of the country.

Sunday, August 2, 2015

Boosting the Bumbles

After a month and a half of blooming, my Hypericum shrubs are winding down. Known commonly as St. John’s wort, Hypericum is a genus of annuals, perennials and shrubs with 31 species that are native to Georgia. I have written about this genus before, so I won’t repeat, but these plants always highlight for me the support that bumble bees need.

Bumble bees on Prenanthes
Whenever my Hypericum flowers are open, they are covered in bumble bees, especially the common but oh-so-adorable Eastern bumble bee, Bombus impatiens (named by the way, for the genus of plants Impatiens, such as our native jewelweed, I. capensis, which they like to visit). Even when the Hypericum is not flowering, these native bees come visiting to check out what is flowering. In the spring, for example, they love beardtongue flowers (Penstemon).

Bumble bee on Agastache
Bumble bees are one of the few species of native bees that are social. While they don’t make honey, they do create a cluster of wax-brood cells in small hidden spaces such as an old hole or under a clump of grass. Workers tend to the larvae in the cells, bringing more provisions as needed. Small quantities of nectar may be stored for use by the colony. This is unlike solitary bees that provision the larvae once and then do not return.

The nest is only used for one year, and the workers die over the winter. I hope one day to find a nest (even an old one). I feel sure that there is probably one somewhere on my property given how many worker bees that I see. You can see a good picture of a nest here.

There are several recent articles out lately about bumble bee population declines and the trend is disturbing. Bees are being affected by pesticide use via the movement of pesticides through the nectar and pollen that they collect. In addition, a study on insect response to climate change shows that they are less likely to move north even while their populations are diminishing in their southern ranges.

Bumble bee on Eupatorium
I have noticed what other flowers that bumble bees visit in my yard. They include anise hyssop (Agastache foeniculum), Eupatorium, rattlesnakeroot (Prenanthes) and some of the non-native herbs that I grow like oregano, catnip and basil. If you grow those herbs, let them go to flower every now and then and see what you get. Their tiny flowers are just perfect for bumbles. Holly (Ilex spp.) flowers are also so popular that I tell people not to plant hollies if they don’t like bees.

Bumble bee on Hypericum

Bumble bees are worth supporting and provide a lot of important pollination services. If you would like to support them, observe what flowers they visit already and add more or try one of the ones mentioned here.