Frog Update and More

In case you did not see my Facebook post, we have determined that our resident frog, whom we have affectionately named, "Gladys," is actually an American bullfrog, Rana catesbeiana. She's a female, for sure, because her throat is marked with brownish gray markings over her white skin, whereas male bullfrogs have yellow throats. Bullfrogs are generalized ambush predators, and are unique among our native frogs in having the ability to catch underwater prey. Demonstrating this several times each evening, Gladys feeds voraciously on the little fish attracted to the surface of our pond when we add food pellets for the goldfish. She can leap a foot or more to pounce on the distracted guppies. She supplements the fish with insects. I was trying to photograph a mating pair of dragonflies when Gladys appeared out of nowhere and snapped up them both before I could snap the shutter.

Male Tiger Swallowtail

One of our favorite late summer insects is the tiger swallowtail butterfly, Papilio glaucus. This is the largest butterfly in our area, and is unmistakable as it flits from flower to flower, preferring to be out and about when the weather is hottest in mid-afternoon. Nevertheless, it remains active until almost dark. In our garden, it feeds on Joe Pye weed (Eutrochium maculatum), Texas sage (Salvia coccinea), scarlet sage (S. vanhouttenii), marigolds (Tagetes hybrids), and the tropical milkweed, Asclepias curassavica. The butterfly lays its eggs on tulip poplar trees, and the enormous caterpillar is rarely seen outside the tree tops. In our area, we mostly have the black form of female tiger swallowtails, and only the males are yellow. That is because we also have the pipevine swallowtail, which the female tiger swallowtail mimics. Birds that try a pipevine swallowtail will quickly learn that it is not good to eat, and they react to the imposter tiger swallowtails by avoiding them. Some other butterflies also practice this form of deception, known as "Batesian mimicry."

Beans, okra and peppers dominate our garden harvest this week. We are picking okra every day and beans about every three days. The current bean crop is 'Provider,' and, boy howdy, is it properly named. We have made three pickings already and a fourth will soon be ready. The beans get amazingly long, up to eight inches, before the seeds swell much, and they remain completely stringless even if a bit over-mature. They are easy to pick and the flowers are a decorative pink color, too. We will grow this one again next year. It is great for any recipe calling for green beans.

We have not been impressed with the productivity of the dwarf okra cultivar, 'Baby Bubba.' We pulled this one off the Burpee rack just to try. While it definitely bears okra while remaining under three feet tall, we should have twice as many plants as we do in order to provide a reasonable harvest. By "reasonable harvest," I mean three or four servings of okra every three days. Picked pods keep only about three days from harvest, so unless you have lots of recipes calling for a little bit of okra, I suggest sticking with a small planting of old standby 'Clemson Spineless.' After we received 3/4 inch of rain last Thursday, the pods have really begun to set, forcing us to pick daily. This variety is also tops for flavor, according to many people.

From now until the week after Labor Day is the preferred time to plant garlic. Choose the largest bulbs from last year's crop and plant the largest cloves from these bulbs, to insure the biggest and best crop next season. Garlic needs fertile, weed-free soil, but thrives here with little extra attention. Purchase seed garlic from your favorite independent garden center, or just plant organic garlic from the grocery store.

The Busy Time of Year

If you're not busy this week, you're not gardening! I've been working around the rain showers all week. We transplanted tomato and parsley plants, and planted cucumbers, corn and beans. We have a second round of tomatoes and our pepper crop to pot up to four inch pots from the cell trays in which they germinated about three weeks ago. And it is time to start more basil and parsley seeds for transplanting in late June or early July.

I find it is hard to have too much of either parsley or basil during the summer months. For one thing, both go great with tomatoes and cucumbers, the king and queen of the summer veggie garden. Parsley is also a preferred host plant for the black swallowtail butterfly. Hardly had I put my four new plants into the garden when they were visited by a female black swallowtail, deftly placing individual eggs here and there on my plants. I don't mind, as the colorful green, yellow and black striped caterpillars don't usually kill the plants. After the caterpillars are done, the parsley usually bounces back and provides plenty of leaves for the table. I do try to give them a little cottonseed meal or other nitrogen source, to help things along.

The relationship of parsley and parsley worm involves more than eating and being eaten. The chemicals that give parsley (and other members of the celery family) its distinctive flavor provide the caterpillar with raw materials for an interesting defense against its predators. When disturbed, the caterpillar rears up and exposes a specialized scent gland, the osmetarium, releasing an unusual odor, faintly reminiscent of...parsley. The osmetarium looks like a pair of antlers, yellow orange in color. Besides parsley, the caterpillar feeds on carrots, dill, celery and golden alexanders. You may see the caterpillar on Queen Anne's lace, which is a feral carrot.

The corn variety we selected this year is Ambrosia. It is a bi-color, sugar enhanced hybrid cord that bears early. In other words, purely the creation of plant breeders. Modern hybrid sweet corn, however, is not only easier to grow than older types, it is much more forgiving to the novice gardener who may not be sure when to pick. With, for example, Silver Queen, the window of perfection may only be a couple of days. With Ambrosia, you can be off by a week and still have an acceptable quality ear. Corn takes a lot of room and a lot of nitrogen, and you can buy it for $5 a dozen at the farmer's market. But there is nothing like truly fresh sweet corn for summer flavor.

We are growing an old standard cucumber, Boston Pickling. I intend to convert at least six pounds of our crop into a batch of my grandmother's sweet pickles. Last year was a lousy season for cucumbers. We are hoping for better results this year.

We planted Bush Romano and Goldrush beans. The former are long, flat Italian-type beans that are loaded with flavor and can stand up to long cooking. The latter are yellow wax beans that are perfect for summer salads after a brief blanching. Beans can be planted every two weeks from now until the middle of July, for a continuous harvest. Later plantings are more subject to bean beetles than are earlier ones.

UT Gardens Farmer's Market Now Open
Last Wednesday, May 15, I had the pleasure of staffing a question-and-answer table at the UT Gardens Farmer's Market. Thanks to the efforts of market director Becca Mattingly and a great group of local farmers and craftspeople, the kickoff was a huge success. The market is open every Wednesday from 4:00-7:00 PM at UT Gardens off Neyland Drive. Parking is free, there is music and food, a tent-full of activities for the kids, and the area is pet friendly. You can tour the gardens, grab a Vietnamese spring roll or a Tennessee fried pie and shop for dinner all in one place. I tried the Thai-style iced tea and loved it. Wildflower honey and organic beauty aids all await your perusal from Honey Dew Naturals of Strawberry Plains. Baked goods from great local vendors like Hillside Bakery and VJ's complement all the fresh produce and cut flowers on display by multiple growers. I or another person will be there to answer your gardening questions every week, so please drop by and say hello.

Redbuds - The "Perfect" Tree

Our Plant of the Week on "Garden Talk" this week is the eastern redbud, Cercis canadensis. After discussing this tree with co-host Dr. Sue Hamilton, Nancy Schneider (woody plant specialist at Stanley's Greenhouse) and UT horticulture student David Pease, I have concluded it must be the "perfect" small tree for the Tennessee Valley region.

 

Besides welcoming spring with its display of pink blossoms, the eastern redbud offers the gardener many advantages. It grows easily in most soils. Because it is a legume, it actually helps to build the soil underneath it, by fixing atmospheric nitrogen with the help of bacteria living on the roots. Although tent caterpillars sometimes find the tree tasty, they are generally easy to control. The redbud has few other insect pests. Older trees are susceptible to trunk canker, a fungal disease that eventually kills the tree, although many specimens endure for a long time before succumbing to this problem. Otherwise, redbuds are carefree.

Transplant redbud trees from late fall until early spring. Container grown specimens typically bloom the year they are transplanted. Set the plants slightly higher than the surrounding soil, in order to avoid covering the crown. Water in and mulch. Irrigate if rainfall is insufficient. After the first season, the tree will be much more drought tolerant. Fertilization is not needed and may reduce bloom. Adaptable to many soil types, the redbud does best in well-drained, moisture retentive soil with organic matter.

Redbud trees grow easily from seeds, which are borne in pods that look like small snow peas. As a result, many cultivars and selections exist. Some of these are:

• 'Alba' -- a white-flowered form (f. alba) that comes true from seeds, sometimes incorrectly sold as 'Texas White"
• 'Dwarf White' -- another white-flowered redbud, it remains under 10 feet tall
• 'Forest Pansy' -- with new foliage that is deep burgundy red, this variety blooms later than the wild type
• 'Silver Cloud' -- white leaf variegation on a tree that prefers light shade
• 'Pink Heartbreaker' -- a weeping form that does not need staking to remain upright
• 'Covey' -- a dwarf weeping form that grows upright only if staked; unstaked plants will sprawl and become a ground cover

Besides our native eastern redbud, other species are sometimes available in garden centers. These include the western, or California, redbud (C. occidentalis) and the Chinese redbud (C. chinensis). The California redbud forms a multi-stemmed shrub when grown in the Tennessee Valley and is more sensitive to trunk canker than the eastern species. Chinese redbud is resistant to trunk canker, but grows much larger than the North American species, about 40 feet.

Flowers of the redbuds are edible. Native Americans used redbud for medicinal purposes. The flowers can be fried in batter, or mixed with nuts and honey or chopped dried fruit. Flower buds may be pickled like capers, and the green seed pods can be used much like snow peas in sautes and stir-fries. Honeybees and other pollinators are attracted to redbuds, and the eastern redbud is the host plant for Henry's elfin butterfly (Callophyrus henrici).

Save the Monarchs!

One of the many pleasures of gardening is watching the butterflies that visit our flowers. Like so many other wild things, our local butterflies appear to be in trouble. The number and variety of species that I see dwindles each year. There has been a noticeable shift from larger species, such as the fritillaries, to smaller, more nondescript one, such as skippers. This shift may reflect the shift in vegetative cover in this area from deciduous woods to open fields, and the loss of habitat to development.

Yesterday, a disturbing report  revealed that the population of monarch butterflies (Danaus plexippus) has crashed in the last decade. Mexican scientists report that wintering populations that previously covered 50 acres of trees this season covered only 3 acres. Several possible reasons for this sharp decline, all related to human activity, have been proposed.

One explanation for the serious decline in the numbers of this beautiful butterfly may lie in the severe summer heat and drought that has been experienced in the central and southern states in recent years. The unusual weather patterns may result from climate change.

Another possible factor is the loss of habitat in Mexico, where the butterflies spend the winter, due to logging.

A third possibility is the widespread use of GMO crops, specifically "Roundup Ready" soybeans in the United States. The genetically engineered soybeans are unaffected by the herbicide, glyphosate, making it possible for farmers to almost completely eliminate milkweed from their fields. Milkweed is the food plant for the monarch's caterpillar. Adult monarchs feed on a variety of nectar plants, but the caterpillars will only survive on milkweeds.

Tennessee has 13 species of milkweeds, including butterfly weed (Asclepias tuberosa), swamp milkweed (A. incarnata) and common milkweed (A. syriaca). These three are often available in garden centers that carry native plants. Several of our other species have showy flowers and could be valuable garden plants, also. Milkweed seeds germinate readily and the plants are easy to care for, in my experience. Many have a pleasant fragrance, as well.

For a small donation, you can receive milkweed seeds appropriate for planting in your garden from this web site, LiveMonarch.comhttp://www.livemonarch.com/free-milkweed-seeds.htm

Our local garden centers, including Stanley's Greenhouses, Ellenburg's Nursery, and Mayo Garden Centers, all offer Asclepias plants among their perennials flowers. You can also often find a tropical species, A. curassavica, which won't overwinter here but will charm you with its fiery red and yellow blooms.

Milkweed seed pods are among the most familiar sites along our back roads in late summer and early fall. You can harvest a few seeds from wild plants and grow them out at home. Wait until the pod has split and seeds are being released to collect them. Sow immediately outdoors, marking the spot well, and look for seedlings the following April or May. Transplant them to their permanent location, water well, and wait. They will bloom in their second or third season, depending upon the species and growing conditions.

Appropriate growing conditions for milkweeds depend on the species. Swamp milkweed, as you might guess, likes moist places. I see the flowers shining among other types of foliage in roadside ditches that hold water. Butterflyweed, on the other hand, likes dry, sharply drained sites. I have seen beautiful specimens growing out of crushed limestone fill on roadside embankments. Common milkweed seems to prefer average moisture and soil conditions, no doubt accounting for its widespread distribution.

This spring, why not add a few milkweed plants to your garden to help feed the monarchs?

Bees, Butterflies, and Pesticides

Evidence is mounting that widespread use of supposedly "safe" chemical pesticides may lie at the root of the problems currently being experienced by beekeepers. One report can be found here. The study mentioned in this report found that feeding bees artificial nectar spiked with the neonicotinid insecticide imidocloprid in tiny amounts resulted in bee behavior like that associated with colony collapse disorder. While the maker of the insecticide, Bayer, debunks the study, I cannot help but wonder if we are ingesting this pesticide any time we consume a product containing high fructose corn syrup (HFCS). Traces of imidocloprid can be found in commercial HFCS, according to the author of the study.

Neonicotinid pesticides mimic the nicotine found in tobacco, a natural pesticide that affects a great many types of insects. Nicotine is particularly effective against the caterpillars of moths and butterflies, several of which feed on tobacco, tomatoes, potatoes and related crops. An anecdote from my garden a few years ago serves to demonstrate how effective nicotine is. During one particularly bad season for tomatoes, we inadvertently allowed a number of flowering tobacco plants (Nicotiana sylvestris) to grow too near the tomato patch. The sweet scented blooms of the tobacco attracted hornworm moths that laid eggs on both the tobacco and the tomatoes. The caterpillars started munching both types of plants, but those on the tobacco became stunted and died when they were about and inch and a half long, too small to do severe damage to the foliage. Those on the tomatoes, however, thrived, growing much larger and doing considerable damage before we could discover and remove them by hand.

One wonders, therefore, if the severe decline in butterfly abundance, observable to anyone who takes an interest in butterflies from one year to the next, might also be a result of chemicals in the environment. A decade old report found, for example, that pollen from corn genetically engineered to contain a pest-killing substance was harmful to monarch butterflies. How many other products that are commonly applied to lawns, flowerbeds and farms contribute similar effects? No one knows. But everyone agrees that butterfly populations are declining, and last March, this report appeared, suggesting that glyphosate, the active ingredient in herbicides such as Roundup, is seriously affecting monarchs and is turning up in humans, too.

There are a limited number of circumstances under which a home gardener might have to resort to chemical pesticide use. Situations involving noxious weeds already established on the property and ineracdicable by hand cultivation can be handled by spot treatment with glyphosate or triclopyr. Otherwise, I cannot think of a good excuse to use either herbicide.

I can think of NO circumstance under which I would resort to a chemical insecticide, with the possible exception of a termite infestation of my house. And then I would have the treatment done by a professional. In the garden, we have learned that proper husbandry and integrated pest management techniques suffice to protect our vegetable crops, and we only grow ornamental plants that are typically pest-free in our region when properly sited and maintained. Many of our plants are native to the southern Appalachians and have natural resistance to pests and disease.

All home gardeners should follow similar guidelines. Chemical pesticides are both expensive and harmful to wildlife.