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Honeybees helping humanity

While weeding around my tomato plants the other day, I paused for a moment and marveled at the way their flowers almost magically develop into fruit.

Grasping a lemon-yellow flower between my fingers, I smiled and visualized the red, vine-ripened tomato the blossom would become one day.

This miraculous transformation from flower to fruit occurs through pollination–the transfer of pollen or male cells from the anther to the female cells on the stigma.  Wind pollinates tomatoes by shaking the flowers and transferring the pollen.  Sweet corn also relies on the wind for pollination, but only to catch airborne pollen on the silks.  Squash, like most vegetables, depends on insects for pollination.

One of the best insect pollinators known since ancient times is the honey bee which was introduced to North America by European settlers in the 1600s.  (Native Americans called these honey bees the “white man’s fly.”)  Honey bee pollination is not intentional, just a result of the insect’s search for its favorite foods–pollen and nectar.  While the honey bee scrambles around inside the flower, searching for the small oasis of nectar in the nectaries or scooping up pollen from the anthers, pollen from its body lodges onto the sticky surface of the stigma.

Although the honey bee’s way of life and work ethic make it an ideal pollinator, it is the insect’s physical makeup that results in efficient pollination.  The honeybee is to flowers what Tiger Woods is to golf.

Its large compound eyes offer a wide range of vision and sensitive antennae, and its tongue acts either as a spoon for licking up small drops or a pump to rapidly draw in large quantities of nectar or water.  The honeybee’s hairy body collects pollen as it dashes from blossom to blossom.  Combs and brushes on the legs are used to remove the pollen from the flowers or from the body and stuffed into “pollen baskets” in the legs.

For honeybees, pollination is just a matter of survival.  But for Americans, the pollination of millions of acres of crops by honeybees translates to dollars. In South Carolina, commercially grown crops that depend on honey bees for pollination include apples, blueberries, cantaloupes, cucumbers, squash, strawberries, and watermelons.

Those impressive figures show how important a role the honey bee plays in agriculture.  However, honey bees and their brethren–wild bees, bumble bees, and others–assume a critical role in nature.  They pollinate the flowers of many seed- and fruit-bearing plants which are cherished by wildlife.

So, you can see how devastating a shortage of domestic and wild honey bees could be.  In the past 10 years, tracheal mites and varroa mites have greatly reduced the honey bee population.  Fortunately, these pests can be controlled by beekeepers.  But the widespread use of pesticides toxic to bees also has reduced their numbers.  Most bee poisonings occur when bees visit flowers that were recently treated with an insecticide.

Home gardeners can help protect honeybees.  When using insecticides that control a broad range of insects, apply the material when bees aren’t actively foraging in the garden.  It may mean making your applications very early in the morning or late in the evening.  Don’t forget to always read and follow the label directions.

Thinking about the reduced number of honeybees and seeing the blooms on my squash, cucumbers, peppers, and watermelons, I wondered about the future of this year’s crop.  What if there wasn’t sufficient honeybee pollination?  Wouldn’t I be reduced to scurrying from blossom to blossom with a cotton-tipped swab, daubing tiny pollen grains on the impatient stigmas?  It might work, but I’m no Tiger Woods of the blooms.  When it comes to pollination, I’d rather have it done by an expert.

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Hot chile peppers: the Dark Side of horticulture

About a month ago a friend of mine brought in two zip-loc bags of hot chile peppers. I was surprised to learn that these chiles (Capsicum chinense) hadn’t succumbed to frost/freezing temperatures. I more surprised to learn that one was ‘Trinidad Scorpion’ (the one on the left in the photo) and ‘Ghost’ (the one on the right). ‘Trinidad Scorpion’ weighs in as the 3rd hottest pepper in the world with 1.5 million Scoville Heat Units  and ‘Ghost’ (a.k.a. Bhut Jolokia) takes 4th place with 1 million SHU (http://www.chilepepperinstitute.org/content/files/Top%2010%20Hottest%20Chile%20Peppers.pdf). The hottest pepper in the world with over 2 million SHU is ‘Trinidad Moruga Scorpion’ (http://www.chilepepperinstitute.org/content/files/trinidad_moruga_scorpion_pepper_hottest.pdf). As a point of reference, the relatively “mild” Orange Habanero takes 9th place with 250,000 SHU.

'Trinidad Scorpion' (left) and 'Ghost' (right) chile peppers.

‘Trinidad Scorpion’ (left) and ‘Ghost’ (right) chile peppers.

As you know, capsaicinoids, a group of acrid, volatile alkaloids, are chiefly responsible for the “heat” in hot peppers. Interestingly, .the pungency of a single variety can vary from one grower’s field to another. Much of the evidence is anecdotal, involving speculation about degree days, soil type, moisture levels, and nighttime temperatures.  So far, e

xperiments have revealed that stressing the roots of peppers by flooding causes greater pungency, as does providing extra nitr

ogen (contrary to the notion that low soil fertility is responsible).  For more on this research, vist The Chile Pepper Institute at www.chilepepperinstitute.org.

But back to these super hot chile peppers. After having been “burned” by Orange Habanero, I don’t know why I accepted ‘Trinidad Scorpion’ and ‘Ghost’. Perhaps out of fear for my family, I kept these hot peppers in my office. As I watch them shrivel and blacken, I wonder why I’d want to grow  these peppers next summer. Anything above 100,000 SHU is unpalatable to me, but I’m attracted to their appearance and their inherent danger. Perhaps I’m venturing to the Dark Side….

There’s nothing finer and easier than figs

When it comes to home-grown fruit, nothing could be easier than figs. Cultivated for thousands of years, figs can remain fruitful for many generations. There are about 470 varieties of common figs—the ones we grow in the southeast. Two of the most commonly available and highly recommended figs for us are ‘Brown Turkey’ and ‘Celeste.’ ‘Brown Turkey’ produces purplish brown figs that occur over several months. It’s winter hardy to 10 degrees F. ‘Celeste’ bears smaller, violet-brown skinned fruit. The tree itself is more winter hardy than ‘Brown Turkey,’ capable of surviving temperatures as low as 0 degrees F. Both varieties produce excellent fruits that can be eaten fresh; however, ‘Celeste’ figs have more culinary versatility: the fruit can be dried or processed in preserves, glazed tortes, and compote.

Figs are not like those “no pain-no gain plants.” In fact, its seems unfair to expend so little effort to reap so many tasty rewards. Because they demand so little from their caregivers, you should plant one or two in your garden. Figs prefer a well-drained, full sun location. Depending on the variety, some are more cold hardy than others. For protection from winter winds and cold temperatures, marginally cold-hardy figs should be planted on the south-facing side of your home close to a heat-absorbing brick or stone wall. Figs have the potential for reaching heights of 15 to 30 feet or more, but they can easily be maintained at 6 feet, which keeps the fruit within reach. They sucker quite easily, so you should pay attention to controlling or at least accommodating their rampant spread. Fig trees are light feeders, requiring little or no fertilizer. Fertilize your fig when the leaves appear off-colored and smaller than normal, and when it produces less than a foot of growth a year. Any complete fertilizer will be fine, such as a 10-10-10 applied when growth begins in the spring. If necessary, a second application can be made in early summer.

Although figs are heat-tolerant and can cope with dry periods, watering during exceptionally droughty summers will prevent them from shedding their fruit. If you’re looking for a great tasting fig, take a look at my fact sheet titled  “Fig” at the Clemson Extension Home & Garden Information Center web site. Of course, visit your favorite garden center or nursery now when the figs are fruiting. Let your palette decide which variety deserves to be in  your landscape.

Since figs make great passalong plants, make friends with someone who’s already growing them. My ‘Brown Turkey’ came from a friend in Seneca, SC about nine years ago. After I pruned his 20 foot tall tree in late winter, he tried to pay me for the exercise. I declined the money, but took a branch home with me instead. I dug a trench about 6 to 8 inches deep, placed the limb on the bottom so the branches rose slightly above the ground, and filled it in. It leafed out and grew the first year. In the following year, I was eating figs in my backyard. You don’t have to cram an eight foot limb in your trunk like I did. Dig up and transplant suckers, or take 8- to 10-inch long cuttings of one-year-old wood in early spring. Set the cuttings in a prepared bed so one or two buds on the tip are above the ground. Let them grow for a season before transplanting them.

For the past three summers the scarcity of rain coupled with my reluctance to water resulted in a mediocre crop. Fortunately, this summer was different. I’ve got a bumper crop of figs and I’m the only one in my family who relishes the sweet, soft fruits. Sure, I have to compete with the birds and insects, but thankfully, there’s plenty of figs for everyone.

Seedless or seeded, warm or cold, just give me watermelon

No matter how you slice it, there is no summer without watermelon.  Royalwatermelon_USDA Sweet or Icebox, seeded or seedless, I’m not too finicky about watermelon. According to USDA estimates, each American consumes about 15 lbs. of watermelon a year.  By late July I’m way ahead of that mark.
While the interest in personal watermelons is warming up, the demand for seedless watermelons is red hot. Although several years have passed since seedless watermelons were first developed in 1939 at Kyoto University, Japan, they comprise about 70 percent of the watermelons grown in South Carolina.
Just the other day while eating a seedless watermelon with my kids, I lamented about their absence of seeds. Besides missing their crunchiness, I couldn’t showcase my prowess as a long distance watermelon seed spitter.
My kids, on the other hand, wondered where the seeds of seedless watermelons came from.  I told them that the parents are two seeded varieties. The male is a diploid variety, that is, a watermelon with the ordinary number of 22 chromosomes.  The female parent, however, is a tetraploid variety:  one that has been chemically treated to double the chromosome number to 44. (I believe it was at this point in my lecture when they tuned me out.)  The resulting hybrid seed is a triploid with a chromosome number of 33. Although these triploid seeds will sprout, the resulting watermelon plant is sterile. The vine flowers and makes fruit, but the fruit are seedless.
Growing seedless watermelons is more challenging than raising ordinary watermelons.  Seed of the latter will germinate at 75 degrees. Seedless watermelon seeds, by contrast, need at least 80 degrees and preferably 85 degrees to sprout. The thick seed coat sometimes sticks to the cotyledons on the emerged seedlings requiring them to be carefully removed by hand, although sowing the seed so that the pointed end is down reduces this seed coat-sticking problem. Seedless watermelon flowers must be pollinated to set fruit, but because the plants produce no pollen of their own, a seeded watermelon variety must be grown nearby. These seeded watermelons will set fruit of their own, but these are usually selected to have a different shape or rind color to make
it easy to distinguish the seeded and non-seeded fruits.
While many of you search for seedless watermelons–not me.  I¹m look for Charleston Gray watermelons that are too big for the refrigerator, but small enough to lie on a bed of ice in my daughter’s red Radio Flyer wagon.  I hope your summer is as sumptuous as mine.

Pineapple Guava

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Pineapple guava (8 ft. H x 8 ft. W) at the SC Botanic Garden, Clemson.

The pineapple guava (Acca sellowiana), formerly known as feijoa, is a small, subtropical evergreen tree that’s hardy to about 10 degrees F. In tropical regions it can reach a height of 10 to 15 feet with an equal spread, but in warm temperate areas like ours, expect it to grow 8 to 10 feet high and wide. It’s cultivated for its extraordinary flowers, which are about 2 inches wide and have white sepals arching downward to reveal bright red petals with white margins. In the center of each flower is a cluster of bright red stamens tipped with tipped with g

olden pollen. The green round to egg-shaped fruits, which mature into 2 to 4 inch long blue-green to grayish-green berries, can be harvested in late summer and fall.

Besides the flowers, I’m also enamored with its dense rounded habit and lustrous, almost bluish-green leaves. When breezes lift and turn the leaves over, admire their fuzzy-white pubescent undersides.

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Close-up of pineapple guava berries the first week of July at the SC Botanic Garden.

Besides the flowers, I’m also enamored with its dense rounded habit and lustrous, almost bluish-green leaves. When breezes lift and turn the leaves over, admire their fuzzy-white pubescent undersides.

Besides purchasing it from a reputable nursery, you can also root cuttings of self-fertile cultivars, such as ‘Coolidge’ or ‘Nazemetz.’  ‘NCSU Hardy‘ is a more cold hardy species introduced by NC State University. Expect rooted cuttings to bear fruit in two or three years, whereas seedlings may take four years or more to bear.

Pineapple guava needs a well-drained soil, with a pH between 6 to 6.5.  It also needs to be mulched and watered during dry spells to prevent fruit drop.  They have few, if any, pest problems.  For more information about pineapple guavas, see “Fruit Facts” at the California Rare Fruit Growers web site (www.crfg.org/pubs/frtfacts.html).

Pomegranates are good for you and your landscape

Although pomegranates have been cultivated since ancient times, few southern gardeners include this deciduous to semi-evergreen large shrub or small tree (height and width of 12 to 15 feet or more) in their landscapes.  Besides its glossy green leaves, pomegranates produce gorgeous carnationlike flowers during June and July.  They are about an inch wide and comprised of 5 to 8 crumpled petals.  They occur singly or in groups of twos and threes at the ends of the branches.

Pomegranate tolerates acid or alkaline soils and can be sited in full sun to part shade.  However, best growth occurs in regions with hot summers and cool winters.  The pomegranate can be grown as far north as Washington County, Utah, and Washington, D.C., but not expected to bear fruit.  Domant pomegranates can tolerate temperatures down to 12 degrees F; however, severe damage can occur from late spring frosts when new growth emerges in the spring.  Commercial pomegranate fruit production is centered in the Bakersfield-Fresno area of California.DSC_0040pomegranate_BP

There are basically two kinds of pomegranates:  cultivars that produce sweet- or tart-flavored fruits and those that do not bear fruits.  Many ornamental pomegranates have been selected for their showy flowers, especially those with double flowers that look like carnations.  The fail to set fruit due to the abnormal structure of their flower parts.  Although pomegranate flowers are typically hermaphroditic containing both male and female stamens an pistils, some nonfruiting cultivars have unisexual flowers or have flowers whose pistils degenerate or are nonfunctional.  A few double-flowering pomegranates include ‘Alba’ (double white), ‘Mme. Legrelle’ (coral-red with white variegation), ‘Nochi Shibari'(dark red), and Tayosho (apricot).

Fruiting cultivars bear round reddish-green to violet fruit about 3 to 5 inches wide that have a leathery rind.  The fleshy seeds are enveloped in a juicy pulp, which may be sweet or tart-flavored depending on the cultivar.  These healthy fruits provide potassium and vitamin C and are chock-full of antioxidants. Cultivars grown for their fruit include ‘Wonderful’, in cultivation since 1896, which bears double orangish-red flowers and greenish-red to reddish-orange fruit.  The juice is mixed with sugar and water to make grenadine syrup.  ‘Grenada’, is a close relative of ‘Wonderful’ with sweeter, darker fruit.  ‘Ambrosia’ has gold rind with a red blush, while the rind of ‘Sweet’ remains slightly greenish with a red blush when ripe.

While folks may either like or dislike this unusual fruit, there’s no disagreement about the flowers.  Granted, it may be an acquired taste.  But there’s no disagreement about the flowers:  they’ve been captivating civilizations for centuries.

For more information on growing pomegranates in South Carolina, see  “Pomegranate”, HGIC 1359 (http://www.clemson.edu/extension/hgic/plants/vegetables/tree_fruits_nuts/hgic1359.html

Blueberries: incredible edible ornamentals

Blueberry SCBG

Northern highbush blueberry, SC Botanic Garden, Clemson

The genus Vaccinium includes more than 150 species of evergreen, semievergreen, or deciduous ground covers, shrubs and trees; however, very few of the species are cultivated in our gardens.  The most widely cultivated plants are those bred and selected for their edible fruits: northern highbush (V. corymbosum), rabbiteye (V. ashei), southern highbush (hybrids derived from crosses between northern and native southern species, mainly Darrow’s evergreen blueberry [V. darrowi]), and lowbush blueberry (V. angustifolium).

Rabbiteye cultivars are best suited for most of South Carolina.  You will need at least two cultivars to ensure adequate cross-pollination.  Dozens of early, mid- and late-season fruiting cultivars are available. For the Midlands and Piedmont of SC, good choices include Alapaha, Vernon, Premier, Brightwell, Powderblue, Ochlockonee, Centurion.  For Coastal SC, both rabbiteye and southern highbush cultivars could be used.  Good choices there include Rebel, Star, Camellia, Palmetto, Emerald, Windsor, Farthing, Sweetcrisp, and Suziblue.

Consult your local Cooperative Extension office for a list of recommended blueberry cultivars for your region (e.g., North  Carolina and Georgia). Also, see the Southern Region Small Fruit Consortium for additional information on growing small fruits in the Southeast.

Blueberries are not beautiful for only their fruits.  These edible shrubs have dark blue-green leaves, white to pink bell-shaped flowers, stunning fall color that can include mixtures of orange, red, and yellow, and colorful, red, yellow, and green stems in winter. Tuck blueberries into your landscape with other acid-loving plants–ericaceous plants such as azaleas, rhododendrons, and pieris. Their multi-season attributes will make your borders, hedges, and perennial plantings pop.