Summer begins

Male ruby throated hummingbird (Archilochus colubris) at one of our feeders

Last Monday was Memorial Day, the traditional start of the summer holiday season in the U.S.  In my garden, summer begins when the fireflies appear, and the baby hummingbirds fledge.  We spotted the first fireflies a couple of weeks ago, but this week the population increased dramatically.  When the sun goes down, the garden is filled with slowly flashing yellow lights as the little beetles fly up from the grass and flowerbeds.

During the day, the action is a lot more frenetic.  Since early April, a few adult hummingbirds have been visiting our two feeders, which I refilled once a week or so.  But suddenly there are dozens of hummers jockeying for position, and we go through a liter of sugar solution a day.  Their harsh chattering and the sound of buzzing wings fills the air as they dogfight over the lawn and chase each other away from the feeder or favorite flowers.  Occasionally several will settle down to drink peacefully at the same feeder (four on the small, six on the large), but it never lasts long.  Another soon shows up and starts a chain reaction fight in which the tiny birds orbit the feeder like fighter ships in a Star Wars movie.   I have counted ten or more at a single feeder, and the other is just as busy.

On dry, sunny roadside banks and meadows, patches of bright orange show that the blooming season of native butterfly weed (Asclepias tuberosa) has started, and as Spigelia marilandica finishes flowering, A. tuberosa takes over as my favorite flower in the garden.

Asclepias tuberosa. The best specimen in the garden is a volunteer seedling that sprouted in the gravel path beside the mint patch.

This is one of the best insect plants that you can grow in North Carolina.  Like all milkweeds, it is a food plant for the caterpillars of the monarch butterfly (Danaus plexippus).  Monarchs are becoming very scarce, sadly, and in ten years gardening at this location, we have only had caterpillars one year.  But A. tuberosa flowers provide food for bees and other butterfly species, and those are not in short supply:

Carpenter bee (Xylocopa sp.) visiting A. tuberosa flowers

Pipevine swallowtail butterflies (Battus philenor) on A. tuberosa

When the plants are finished flowering, they attract beautifully colored milkweed bugs (Oncopeltus fasciatus) that feed on the developing seeds.  But no matter; enough seed survives to float away on tufts of fluff, so that more plants appear every year.

Oncopeltus fasciatus nymphs on A. tuberosa follicles.

Once planted, A. tuberosa can be tricky to transplant, because its tuberous roots grow deep and break easily.  If you plant a couple of potted seedlings, they’ll cross-pollinate and give you plenty of seed that you can spread around.  It seems to take about two years for seedlings to reach blooming size, and a couple more to grow a really nice clump.

Much less colorful but still elegantly beautiful, Yucca filamentosa is also blooming now.  I planted it on the dry mound around our wellhead, along with the prickly pears and a few other xerophytic plants.

Yucca filamentosa

It was supposed to be the variegated clone, ‘Color Guard,’ but it seems to be some sort of unstable mutant.  New growths come out variegated, but over the course of the year, they darken until they are indistinguishable from a wild type plant.

On the other side of the house, Hydrangea quercifolia, oakleaf hydrangea is also blooming white.

Hydrangea quercifolia

This is a southern species, with a native range centered on Alabama.  It is a much more reliable bloomer than the Japanese Hydrangea macrophylla, because the new growth is less susceptible to damage by late freezes.

Some cultivated clones have inflorescences made up entirely of large sterile flowers, equivalent to mophead forms of the more familiar H. macrophylla.  However, I prefer the look of wild type plants, equivalent to a lacecap H. macrophylla, with a few sterile flowers surrounding clusters of tiny fertile flowers that attract many bees.

The H. quercifolia flowers are looking their best this week, and they’ll continue to look good until the Japanese beetles, the scourge of summer, arrive to devour them.  That could happen any day.  I saw a few beetles this week, munching on banana leaves, but most will emerge over the next couple of weeks.  If I can keep the beetles from doing too much damage to the hydrangea, its inflorescences will slowly turn pink and will be attractive until well into autumn.  Eventually they’ll dry out and turn brown, but they’ll remain on the plant and, together with the peeling bark, provide winter interest.

Family heirloom

My wife’s maternal grandparents were florists, and they planted a variety of interesting flowering plants in the garden of the house that they built in Lancaster County, Pennsylvania about eighty years ago.  My mother-in-law and father-in-law still live in that house, so I have been able to dig up bulbs and take cuttings of the old plants for my own garden.  Among them is a prickly pear cactus that blooms every May:

Spineless prickly pear cactus

My best guess is that the plant is Opuntia humifusa, eastern prickly pear.  It is completely spineless, with smooth, soft-looking pads and buds that invite one to touch it, but it has a secret weapon.  Instead of spines, each areole has a cluster of glochids, little barbed hairs that detach at the slightest touch.  They’re maddening and virtually invisible.  Removing them from skin requires a good pair of tweezers and a magnifying glass.

Despite the glochids, I think this plant is worth growing for its family history, its beautiful yellow flowers, and its red fruit that remain colorful through the autumn and most of the winter, even after the pads have shriveled in the cold.  Our local chipmunks seem to enjoy eating the fruit.  Then they leave cactus seed poop on the railing of the deck.

Eastern Chipmunk (Tamias striatus) eating an Opuntia fruit in late winter.

In addition to the heirloom Opuntia, I also grow a larger species that is relatively common in local gardens.  This plant has a more erect growth habit with long spines on large pads.  The pads flop over during the winter but do not shrivel as much as those of O. humifusa.  There may be a tag buried down in the middle of the clump, but I am disinclined to search for it.  This will have to remain “Opuntia sp.”

Opuntia sp.

Both prickly pears are hardy, tolerant of humidity and rain, and easy to propagate from pads pulled off the main plant.  I’m not sure if either of our children will be interested in gardening, but I hope someday to be able to pass on to them a piece of great grandma’s cactus.

 

Alien sea creatures?

A tentacled horror from beyond space and time

Aristolochia fimbriata flower

The flowers of the white-veined pipevine, Aristolochia fimbriata, resemble some strange sea creature with an array of tentacles surrounding a rugose head and dark maw.  The “mouth” won’t consume anything larger than the small flies that it attracts as pollinators, but the flowers aren’t the only thing about this plant that is vaguely Lovecraftian.  A. fimbriata is also a host plant for the sinister, spiky caterpillars of the Pipevine swallowtail butterfly (Battus philenor).

Pipevine swallowtail caterpillar

It has been suggested [1] that pipevine swallowtail caterpillars mimic tropical Onychophorans (velvet worms), and the two horns do give it vague resemblance.  I’m not sure the theory makes sense, though.  The caterpillars’ diet of toxic Aristolochia leaves probably makes them less palatable than the velvet worms they are supposedly mimicking for protection, and some other caterpillars that feed on toxic plants (e.g. Monarch and Gulf Fritillary larvae) also have spikes or tendrils as part of their warning to predators.

The heart shaped leaves that the caterpillars feed on are as beautiful as the flowers are weird:

Variegated foliage of Aristolochia fimbriata

Many Aristolochia species are large, climbing vines, but the stems of A. fimbriata stay small, no more than a foot or two long, and instead of twining, they creep along the ground around other garden plants.  This is a plant that plays well with others.

Seed production is quite prolific in my garden, and in some flowerbeds the plants have started to form a very pretty summer ground-cover.  Nevertheless, A. fimbriata doesn’t seem to be an invasive species; the seedlings surround the original mother plants and haven’t spread to other parts of the garden.  And in any case, biological control comes on blue and black swallow-tailed wings.

A. fimbriata is a subtropical species native to southern Brazil, Bolivia, Paraguay, Uruguay, and Argentina.  Its foliage turns to mush at the first frost, but the tuberous roots are completely hardy here in the piedmont.  Seed also overwinters in the mulch of my flowerbeds and sprouts in the spring.

The butterflies arrived early this year, and the first crop of caterpillars have reduced many plants to stubs.  Now, there are chrysalids scattered around the garden.  When ready to metamorphose, the caterpillars will travel a considerable distance to find a good spot:

Pipevine swallowtail chrysalis on a thornless blackberry, about fifteen feet away from the nearest A. fimbriata plants.

The butterflies will probably emerge and lay the next generation of eggs  just about the time the foliage starts to look good again, but hosting such beautiful insects in the garden is well worth a little leaf damage.

Notes

[1] “It has been suggested”–The passive voice here is a weaselly way of indicating that I have read this in various places but haven’t been able to track down the original source.

Box turtles

Eastern box turtle (Terrapene carolina carolina) crossing the road on Easter Sunday.

Yesterday, I was out in the garden and looked down to see one of the resident box turtles right next to my foot.  The kids and a neighbor friend were running around having a nerf gun battle, so I moved the turtle to a quiet spot where he wouldn’t be stepped on and gave him a couple of strawberries.

Om nom nom

Each eastern box turtle has a unique pattern of markings, and by the spots on his head, I recognize this turtle as the one we have named Percy Shelley.  Here he is in 2010 and 2013:

The mess on Percy’s chin in the right picture suggests he has been eating slugs or earthworms.

With its terrestrial habits, its domed shell, and its elephant-like feet, the eastern box turtle resembles a little tortoise, but it is actually a terrestrial member of the pond turtle family (Emydidae).  Its common name, box turtle, comes from the hinged plastron which gives it the ability to close up tight like a sealed box.

The underside of a sealed box turtle showing the plastron hinge. Its head is to the right.

As you might guess from its scientific name–Terrapene carolina carolina–the eastern box turtle is very much a native of the NC piedmont.  In 1979, it was designated the official State Reptile of North Carolina.

It’s not clear that being the State Reptile has done box turtles much good.  They’re still relatively common, but numbers are almost certainly declining due to development and increased traffic on roads.  Box turtles live in relatively small territories, but during the summer they’ll go walkabout, especially on humid mornings after rain.  Many are killed by cars, and I have found turtles with cracked and healed shells suggesting that they had a narrow escape.

When it is safe to do so, I always stop to help turtles across the road. If you want to do the same, be sure to move the turtle in the direction it was headed, so it won’t have to try crossing the road again. And please please make sure that it is safe before getting out of the car.  People have been killed by traffic trying to help turtles across the road.

A very pretty half-grown turtle I found crossing a road last summer.

When we first put up the deer fence, I worried a bit about trapping wild box turtles inside the fence.  It has now been more than five years since the fence went up, and our local residents seem to be doing fine.  Either they have ways of getting through (or under) the fence, or the garden gives them everything they need to survive.  Percy Shelley seems to be an adult male, and I have seen at least one slightly smaller female.  From time to time, I also run across young turtles in the garden, including tiny hatchlings.

Three tiny hatchlings, together with their eggshells, that I uncovered in a damp mulch pile. Each hatchling still has its little egg tooth at the tip of its beak.

The baby box turtle’s carapace becomes more domed as it ages.  The little hatchlings, with their flatter shells, look a lot like their aquatic relatives:

I’m not sure if this hatchling is a yellow bellied slider or a river cooter. I gave it a lift down to the water, as it was heading in the wrong direction.

Hatchling box turtle with carapace not much more domed than its aquatic cousin

A slightly older juvenile rescued from in front of the lawn mower. Its carapace is still fairly flat.

If you want to make your piedmont garden more box turtle-friendly, consider adding a nice pile of wood chips in a quiet corner and leave fallen leaves to rot undisturbed in areas where they don’t disrupt your landscaping.  Salamanders and lizards will also appreciate the effort.  The turtles might like a shallow dish of water, especially during dry weather, but avoid deep, steep-sided garden ponds that a box turtle could drown in.  Box turtles eat a lot of worms, slugs, and snails, so avoid toxic slug pellets.

If you find a turtle crossing the road, please don’t be tempted to take it home to your garden, no matter how turtle-friendly you have made it.  A turtle moved from its home territory will have much more difficulty finding food and safe places to hibernate, and it may be killed trying to find its way back to familiar land.

A white bluebird

A leucistic bluebird (female?) with a normally colored male.

Today the garden had an unusal visitor who will, perhaps, be a temporary resident: a white eastern bluebird (Sialia sialis). Technically, I suppose she is leucistic, because she retains some faint, diluted color, and her eyes and beak are pigmented.  A true albino would have completely white feathers and pink eyes.

I assume she is a female, because she was with a normally colored male who was busily stuffing pine needles into the nest box.  I’m a little surprised, not only by the white bluebird, but also that a new pair is moving in.  There was another pair nesting in that box earlier in the spring, and just before Easter, I saw a clutch of eggs when I quickly looked in.  I suppose the young might have left the nest in the last few days, but if so, this new pair have moved very quickly.  Actually, I suppose this could be the same male, with a new lady friend.  The previous female was normally colored, but I can’t tell the males apart.

If this pair produces a clutch, it will be interesting to see if any of the fledglings are leucistic.  Perhaps not, if the trait is recessive, unless the male is also a carrier.