Of Photoperiods, Poinsettias, and Muscadines

September is something of a reflection time. The weather is getting cooler and we can hope hurricane season is nearly over. You have probably planted your fall garden—or will soon. With climate change we don’t know just what to expect, but we may not get a frost until late November. The vegetable crops should do well and ornamentals will take on more color with cooler nights. Marigolds will look much better and, if your chrysanthemum plants survived the summer, some of them will begin to flower.

The Song says: “But the days grow short when you reach September.” Actually the days began growing shorter in late June but the change was so gradual that you might not have noticed it. Now we get to the tricky part that you may have forgotten. The simple explanation is that some plants bloom in the spring and summer but others wait until fall or winter. This is because of the summer and winter solstices. After June the days get a little shorter and the nights get longer. Gardeners have known of this for a long time and have called plants that respond to the change “photoperiodic.” This meant that, as the days grow shorter (or longer in the spring) the plants will flower. Back in the dark ages (when we were in school), we had to learn which plants were “long day” and which were “short day.” Later research proved that we were exactly backward in terminology: when the days grew shorter, the nights grew longer. This meant that it was really the length of the dark period that caused plants to change from the vegetative stage to the flowering stage. Some picky, picky people tried to change the name from photoperiod to scotoperiod—meaning the period of dark. Luckily, convention prevailed over precision, so we still talk about long day and short day plants.

Poinsettias and chrysanthemums are both “short day” plants, and that creates some problems. Back in the Middle Ages (when we were teaching) big, colorful mums were an absolute necessity if you wanted to take a date to the football game, and they would typically come into bloom at just the right time.

Poinsettias, on the other hand, were not supposed to be in full flower until Christmas. Growers wanted them to stay vegetative until the plants grew to the proper size.

Then someone discovered that the “short day” can simply be a short flash of light to interrupt the long dark period, letting the plants grow and delaying the bloom until it was time.

Ed: When we were growing poinsettias in the greenhouses at LSU, the lights on cars turning into the girls’ dormitories lighted some benches so frequently that we had to provide black shades over the crop to keep it from being delayed too long.

Leon: Friends, Ed is being modest by not mentioning that he did much of the early work on the effects of temperature on the day-length (dark period) that varieties of poinsettias require. Or, maybe he is being considerate, because the explanation would take too long. Anyhow, he deserves the respect of being called “Mr. Poinsettia” for a long time.

It doesn’t take much to get us on the subject of vegetables and fruit, since we think beauty can be edible at the same time. If you don’t have the publication by LSU, “Louisiana Home Vegetable Gardening,” see your county agent and get one. There are a number of contributing authors listed, since just about all topics in the production of vegetables are covered. Dr. Jimmy Boudreaux was the “senior author” before he retired, but his place is being taken by the equally able Dr. Kiki Fontenot.

If you are not into vegetable gardening, but like annual flowering plants, you might consider pansies. They can be grown from seed but it is very difficult; buy some transplants in early October to have blooms all winter. Try to find calcium nitrate in the fertilizer section of the nursery outlet you buy from. If they have it, get the smallest size package, since it is bad about taking up moisture from the atmosphere if you try to keep it any length of time. This is the fertilizer that will give you great results with pansies. Tomatoes also benefit from the calcium to avoid “blossom-end rot.” Use several applications of about a level tablespoon in a gallon of water around the plants—about every two weeks.

Ed: Leon is good about telling me over here in my apartment in Lake Charles about the various crops being grown at the Burden Research Center in Baton Rouge. Muscadines should be ripening about now. People frequently get into terminology problems about muscadines. We will try to clear this up a bit. Muscadines are grapes: Vitis rotundifolia. The European grapes that are used primarily for wine are V. vinifera but there is another American species called V. labrusca that is a good table or wine grape. The Concord grape is from that species.

Now, back to our reliable muscadine.  Why is it called a muscadine? Well, the early European settlers were reminded of the French grape called Muscat because of the sweet taste and strange aftertaste. It wasn’t quite a Muscat, so muscadine meant it was like a Muscat. Then there is the Scuppernong that some people still distinguish from the muscadine—friends, it ain’t so. It is a bronze colored muscadine that was discovered near Scuppernong, North Carolina. Because most other muscadines were shades of purple, this was named a Scuppernong.

The earlier Muscadine varieties were dioecious – a botanical term meaning separate plants for male and female flowers. This meant that you had to have a male “pollen-producer” to ensure crops on the female plants. The discovery of a perfect-flowered plant, with both stamens and pistils in the same flower, led to breeding programs in a number of southern states and the gradual improvement of the fruit. Early varieties had tough skin and the seeds were firmly fixed in a gelatinous center, sometimes inelegantly described as a “frog eye.” Newer varieties show marked improvement as well as larger berry size and cluster size. Even the newer varieties are hardly “table grapes.” The skin is still pretty tough and they have seeds, but they do taste good. Mississippi State has been doing some good research on muscadines and they say that the fruit is very nutritious.

About ten years ago Dr. Betty Ector at the Food Science and Nutrition Department at Mississippi State (Leon’s original institution of learning) was looking at the nutritional value, including anti-oxidants, of muscadines and saw that, skin, seeds, and all, the Muscadine has much more nutritional value than blueberries: 6,800 units instead of the mere 2,400 for blueberries. Try to remember that you eat skin, seeds, and all of blueberries. Betty made a purée primarily of the skin and seeds and found that it was nutritious and bitter, but they could add sugar and make good muffins from it. (“A spoonful of sugar makes the medicine go down…“) Betty has retired and is living in British Columbia, so the project has died. In the future, after our economic situation has improved, LSU might take up the effort, using the newer varieties that aren’t quite so bitter.

At the Burden Center, Charlie Johnson is testing an heirloom grape called Amato that seems to make a good table grape — it’s a hybrid between Muscadine and something else. Now for a short mention of Muscadine wine. It tastes pretty good to us who grew up eating muscadines, but wine people tend to look down on it because of the Muscat after-taste. Friends, we like to promote the idea of using local products but Muscadine wine won’t hold up against the competition. Archeologists say that people have been using European-grape wine for over 8,000 years.

Several years ago someone made wine from oranges, added bubbly water, and sold it as Louisiana Champagne. It tasted good but didn’t sell. The Good Book says: “Drink no longer but use a little wine for thy stomach’s sake and thine often infirmities.” But we think St. Paul was referring to Chardonnay.    

Ed O’Rourke, Jr. and Leon Standifer are the authors of Gardening in the Humid South (LSU Press, 2002), now available in affordable paperback.