Trees, both native and exotics that are not problem invasives, provide much in the way of benefits.
As plants, they are part of the ultimate solar energy source, harnessing the energy of the sun through photosynthesis. Trees provide economic benefit through environmental services, from energy savings via shade in summer and windbreaks in winter, to stormwater remediation. Trees are major job creators for Ohio through our multibillion-dollar nursery, landscape and tree care green industry.
So, agriculture and environment — what about the third pillar of my employer, the Ohio State University College of Food, Agricultural and Environmental Sciences? In fact, that third pillar, food, is also a big reason why trees matter.
That is why, earlier this week, we had an ArborEatum luncheon sponsored by the Secrest Arboretum of OSU’s Ohio Agricultural Research and Development Center, for students of OSU’s Agricultural Technical Institute to discuss with student-leaders some projects at the OSU Wooster Campus. More on that in future Almanacs, but for now let’s consider the tree foods we ate that day.
• Cashews. The cashew tree (Anacardium occidentale) is a short tree, maybe 30 feet tall, but one specimen in its native area in Pirangi, Brazil, is reputed to have a canopy covering almost two acres due to a tendency to grow outwards, with low-growing branches rooting in the soil.
The cashew tree is in the Anacardiaceae family along with pistachio, mango, and Toxicodendron, the genus that includes poison ivy, poison oak and poison sumac. Like these cousins, cashew produces alkaloids that cause skin rashes, in the case of cashew in the shell surrounding the seed.
The kidney-shaped fruit and seed (the “nut” which we eat) are borne beneath a “false fruit,” a swelling of the pedicel and receptacle of the flower. This false fruit ripens to a yellow or red color, upward-orienting (ana) and heart-shaped (cardium), and is called the cashew-apple, used in drinks and chutneys in some cuisines.
The greatest producers of nutritious cashew nuts (five times the amount of vitamin C of oranges, heavy in antioxidants) are in Nigeria and India, with Brazil now seventh. Cashew production only occurs in areas not subject to frosts.
• Pecans. Pecans are not just for Georgia, as evidenced by their Latin binomial of Carya illinoiensis, but Georgia is the top producer in the U.S., which grows over 80 percent of the world’s pecans. Texas is second, and pecan is the state tree there.
This New World native, related to the hickories (genus Carya) and in the walnut family (Juglandaceae), originated from southwest Ohio and southern Illinois to Mexico, has male and female flowers separate on the same tree. It is also mostly self-incompatible, requiring a separate pollinator tree and the wind for pollination.
The wood is used in furniture and flooring, but the buttery seeds are the real deal, exquisite flavor for pies and pralines. It was also used extensively in preagricultural societies, with high calories. Pecans are high in antioxidants, have been shown to lower bad (LDL) cholesterol levels and have high levels of omega-6 fatty acids, though only half as much as black walnuts.
Thomas Jefferson planted these “Illinois nut” trees at Monticello and gave seeds to George Washington for Mount Vernon.
• Nutmeg. The nutmeg tree (Myristica fragrans) does double duty, with its seeds powdered into nutmeg spice and the arils surrounding the seeds providing the orange-colored spice known as mace. Nutmeg is native to Banda Island, in Malaysia’s Spice Islands, and was the source of significant economic warfare when the Dutch wanted to wrest the production of this valuable spice for their empire. Today nutmeg is grown in Malaysia, southern India, and Grenada in the Caribbean.
The 1-inch-long seed of nutmeg is ground for use in a wide range of dishes and products, from processed meats to vegetable dishes, pastries, ciders and eggnogs, and even as oil in toothpastes and cough syrups. Nutmeg in large doses has psychoactive applications and can be poisonous in excess and especially for certain animals: no eggnog for Lassie!
• Corneliancherry dogwood. Secrest Arboretum horticulturist and chef Paul Snyder has added this small, edible, ornamental tree (Cornus mas) to the feast, in the form of corneliancherry dogwood jam. This edible landscape plant is increasing in popularity in Europe, and research here at the OARDC has explored its use to create a tart yet sweet, ruby-colored cider made from 75 percent apple cider and 25 percent Cornus mas juice. It perfectly reflects its dual nature: very tasty and very beautiful.
Cornus mas is native to southern Europe, the Middle East and southwest Asia, and has many fine ornamental characteristics: masses of chartreuse flowers in late winter or early spring, attractive exfoliating bark, and small oblong reddish-purple fruits in early fall. The fruits are pleasantly tart, but extremely astringent if you are impatient and chomp into firm unripe fruits.
Corneliancherries are high in vitamin C and make wonderful jams, and it is made into a vodka in Armenia. The wood of the tree is very dense, sinks when put in water, and was used for javelins and spears in ancient Greece.
The corneliancherry dogwood jam was intended for a spread on good local seed bread, but it also appeared in unanticipated fashion on some delicious meatballs prepared by chef Katie Cochran. Initially we intended to serve the meatballs with a barbecue sauce made from Dolgo crab apples. Inadvertently the jam was added as a glaze, but in the end the combination of the sweet yet tart jam combined with the crab apple sauce on the meatballs was truly transcendent.
For dessert there was lemon pie, from hybrid citrus trees, and chocolate bars, from the cocoa tree (Theobroma cacao). Literally food of the gods.
Jim Chatfield is a horticultural educator with Ohio State University Extension. If you have questions about caring for your garden, write: Jim Chatfield, Plant Lovers’ Almanac, Ohio State University Extension, 1680 Madison Ave., Wooster, OH 44691. Send email to chatfield.1@cfaes.osu.edu or call 330-466-0270. Please include your phone number if you write.