Gardens of the Cross Timbers: My American Wonder Lemon

Becky Emerson Carlberg
Ponderosa Lemons.
Lemon Flower.

The snow arrived on New Year’s Day, all one eighth inch of it, carried in brisk winds and bitter cold. We Cross Timbers occupants were thrown into the deep end with few days to prepare for the arctic blast. Pots of blackberry plants and lilies were wrapped in insulation, while other plants in smaller pots were lugged into the greenhouse. The radiator, normally stored in the closet, was rolled into the larger greenhouse to become a backup heat source. One could follow the long orange extension cord connected to the heater down the walkway and along the front porch to the outside electrical outlet. The tomato plant, Mountain marigold and pineapples that occupied the far end of the greenhouse should be happy.

Did you ever watch Bonanza on TV? The fictional series was aired from 1959 to 1973, ranking behind Gunsmoke in longevity for western TV programs. During each of the 431 episodes, the sprawling Ponderosa Ranch, which covered 640,000 acres, was a short two-hour ride by horse from Virginia City, Nevada. The ranch was the home for the Cartwright family (patriarch Ben Cartwright and sons Hoss, Adam and Little Joe). Michael Landon (Little Joe) had to wear four inch lifts to match the rest of his TV family!

Virginia City was actually one of the mining camps set up in response to the Comstock Lode discovery in 1859. Six major bonanzas of silver were discovered within five years. The silver was condensed into masses several hundred feet deep instead of in veins. Some of the silver was mixed with gold, forming the natural alloy electrum. Other silver was so soft it could be dug with a shovel, but the excavations often resulted in cave-ins, injury and deaths.

Being rather close to Virginia City, Bonanza was a perfect name for the western. The Ponderosa was a real 24-acre ranch on the Nevada side of Lake Tahoe. The dominant species of pines to the west are Ponderosa pines. Very large fire (low intensity) tolerant pine trees with abundant flexible bright green needles. Ponderosa comes from Latin and means heavy or ponderous.

Exactly why my one lemon tree is called a Ponderosa lemon. It produces heavy ponderous fruits. Decades ago, the Ponderosa lemon was known as the American Wonder Lemon. In 2021, my Wonder Lemon gave birth to several babies. Each gets bigger every day. The orbs decorate the citrus tree like large green balls on a Christmas tree.

Recent genetic analysis of the Ponderosa lemon (Citrus x pyriformis) reveals this is not a true lemon. Lemon trees have a Mandarin orange in their ancestry. Instead, the Ponderosa is a cross between a citron (fragrant large citrus fruit with thick rind; candied citron finds its way into fruitcakes) and the pomelo (largest of all citrus fruits and ancestor of the grapefruit). The Ponderosa lemon does have the acidity and flavor of its cousin, the true lemon.

The Ponderosa lemon tree can reach 12 to 24 feet in height, as proven by the one in my greenhouse. It may bloom throughout the year. Often the fruits and flowers occur at the same time, a characteristic of the citron plant. The large purple edged flower develops into a ‘lemon’ massive enough to make several lemon meringue pies. Single fruits can weigh one to eight pounds. The healthy citrus offspring contain Vitamin C for the immune system, potassium to balance body fluids and Vitamin B6 for energy. Ripe fruits can be left on the tree for months without any loss of quality.

A famous Ponderosa lemon tree grows at Logee’s Plants for Home and Garden in Danielson, Connecticut. Logee’s was founded in 1892. The tree was purchased in 1900 in Philadelphia and taken to Connecticut by train, horse and buggy. Ten years later the tree had outgrown its pot and was planted in the ground. A greenhouse was built around the established tree, later known as “The Lemon Tree House.” That Ponderosa lemon tree became famous in the 1950’s and was even visited by Katherine Hepburn. Martha Stewart later saw the tree and eventually purchased a Ponderosa lemon tree for herself. In 2020, Martha posted a picture of herself holding an enormous Ponderosa lemon from her potted tree growing in Bedford New York. Fragrant, flavorful and mildly tangy. Her tree produces more than two dozen of the humongous fruits every year. Logee’s tree is also still going strong and regularly donates cuttings that are available for sale.

A conundrum. When can I repot my Ponderosa lemon tree in its disintegrating pot? My guess is the tree has covered itself with huge fruits and blooms as a defensive move. Fourteen gigantic vivid green lemons dangle from everywhere. All are now beginning to show a little yellow. The leaves in the canopy at the top of the greenhouse (twelve feet at the apex) usually die back during the winter cold. A natural pruning job, but doesn’t deal with all the lower branches full of thorns. If only the greenhouse was twice the height, my lemon tree would be thrilled. Even better if it was in Florida, since Ponderosa lemons are not as cold hardy as true lemon trees. Not usually cultivated commercially, the Ponderosa lemon trees are manageable house and patio plants if grafted onto dwarf rootstock and kept in check with regular pruning. The pruning part is where I have failed miserably, so the Ponderosa lemon and its buddy next to it, a true lemon, must share tight quarters in an artificial climate created from the heat of radiators, water from buckets and dappled sunlight through the roof inside their translucent plexiglass shell.

What to do with a bumper crop of lemons? Lemon pie, lemon curd, lemon marmalade, lemon pudding, lemon chicken, lemonade, zest, juice or sliced lemons. Australia’s Best Recipes on line lists 42 more things to do with lemons. Time to get cracking.