It has received their undivided attention 10 hours each day, seven days each week since they retired 15 years ago.
From the beginning, an efficient division of labor was in place, with Mrs. Christine seeding and potting - which her husband loathes - while he weeds and mows.
"Sam likes to weed," Mrs. Christine gasped.
Moreover, each gardener harbors a special affection: Mr. Christine loves each of their 300 varieties of day lily, and Mrs. Christine speaks fondly of their 50 different hydrangeas.
No luxury is spared for the thousands of plants, representing about 700 varieties, that transform their 1-acre north Aiken yard into a year-round fabric of outstanding color and vibrancy.
As with a master chef or a jazz virtuoso, the Christines possess an improvisational confidence in their craft.
"If something's not in the right place, we'll dig it up," Mrs. Christine said. Nowhere was this more evident than an empty patch where 40-year-old azaleas had been removed to make way for something new.
Elsewhere, the urge to improvise is facilitated by Mrs. Christine's preference for planting in large pots, which allows her to create bouquets of complementary plants that are swiftly rearranged or crowded beneath trees, such as a sugar maple adjacent to the sunroom whose roots monopolize soil nutrients. They are also loaned to friends and family.
"Giving is the best part" of having such a garden, she said.
The garden's unpretentious appearance disguises its highly controlled nature. Nearly every square foot of the Christines' yard, aside from the lawn itself, grows atop planting soil imported from a manufacturing facility in Anderson, S.C. Plants are seeded and potted in an on-site nursery. A greenhouse protects delicate tropicals through winter.
"The best money we ever spent" was having a well dug to feed an extensive sprinkler-irrigation system, Mrs. Christine said.
The yard has continued to attract journalists and the general public alike, nearly a decade after garnering regional attention through garden tours organized by Clemson University's Extension Service. Recently, an interview on ETV's Making It Grow brought their garden to the attention of two Aiken women who wandered into the backyard one day unannounced, Mrs. Christine said.
The couple accept this attention with a sense of humor, as seen by cheery signs throughout the garden such as the one posted on their back door: "Ring bell. If no one answers, pull weeds."
Reach Darrin Burgess at (706) 828-2946 or firstname.lastname@example.org.
IN THE GARDEN
THE GARDENERS: Sam and Linda Christine
BLOOMING: Cleomes, whose wind-blown seedlings produce blossoms in random places each year, delighting the Christines; red hot pokers in an uncharacteristic shade of yellow; several day lilies, including gloriosos, whose petals resemble torch flames; and bright-orange tuscawilla tigresses ("Sam's Clemson lily," Mrs. Christine said, recalling her husband's alma mater).
GARDEN TIP: Rather than rely on mulch or other plant bed liners to discourage weeds and retain moisture, the Christines condition beds with thick layers of potting soil.