Satsuma ‘Arctic Frost’ has been named a Texas Superstar plant by Texas A&M AgriLife Research and Texas A&M AgriLife Extension Service horticulturists.

The board has named other cold-hardy satsuma mandarins as Superstars: Satsuma Miho and Seto in 2010, and Orange Frost in 2014. From the most successful cold-hardy crosses, Orange Frost and Arctic Frost were selected and propagated.

Arctic Frost, Citrus reticulata, is another Mandarin hybrid resulting from a cross between the seedy, but cold hardy Changsha tangerine and a very high quality Satsuma. The hybrids are the work of Dr. Ying Doon Moy, long time plant breeder at the San Antonio Botanic Garden before his death in November, 2012. Dr. Ying Doon Moy was born in a small village in south China but immigrated to the U.S. in 1978.

Arctic Frost is the most cold-hardy satsuma hybrid tested so far, having survived temperatures as low as 9 degrees at the Texas A&M Research and Extension Center test site near Overton, said Dr. Brent Pemberton, AgriLife Research horticulturist and chair of the Texas Superstar executive board, Overton. Most citrus are easily damaged by the cold, and can only be grown in tropical and subtropical areas, said David Rodriguez, Texas A&M AgriLife Extension Service agent for horticulture in Bexar County and member of the Texas Superstar selection board.

“Moreover, many of the cold-hardy varieties also have a poorer quality fruit,” Rodriguez said. “However, mandarins and Changsha mandarin crosses have more cold hardiness but better quality fruit.”

“Artic Frost fruit peel and flesh is brightly orange colored, retaining that characteristic from its Changsha tangerine parentage,” Dr. Larry Stein, AgriLife Extension horticulturist at Uvalde, said. “The taste is sweet and tart, presenting a true citrus flavor that is missing in varieties that are sweet but bland.” The fruit is easy to peel and only has one or two seeds per fruit.  

Exposure: Full sun; minimum of 8 to 10 hours of sun per day.

Size: “Arctic Frost grows to become a relatively tall tree with white flowers that give off a heady orange fragrance,” Rodriguez said. Come late fall or early winter, Arctic frost produces fruit that is juicy, nearly seedless and easy to peel. It will grow 8 to 12 feet tall and wide in the ground or 6 feet tall as a patio container plant in about five to six years.

Plant Type: Evergreen citrus tree.

Planting Time: Early spring after the danger of frost has passed. “When planting in the ground, protection from cold by wrapping with frost cloth for the first year or two is recommended,” Pemberton said. “A site protected from the north wind will also help with winter survival.”

Suggested Uses: Accent plant for backyard and potential patio containers.

Special Notes: This Texas Superstar should expand the planting zone for citrus in the ground moving as far north as zone 8.  Trees will be on their own roots and will come back true if frozen back.  The tree will also work well in containers.  Adequate fertility and a well-drained potting soil are a must in containers.  Amend the mix with slow release fertilizer and water once a month with a water soluble fertilizer.

“As opposed to other satsumas, which are grafted to another variety rootstock, Arctic Frost is grown from its own rootstock; so if they get nipped back from a hard winter, they do not produce shoots from below the graft,” Rodriguez said.

“Folks that have concerns about the cold might do well to size up the tree with a well-defined root system and strong top canopy for three years as a patio plant before transplanting to the ground.”

Texas Superstar is a registered trademark owned by AgriLife Research, a state agency that is part of the Texas A&M University System. More information about the Texas Superstar program, including retail outlets where Superstar varieties may be purchased, can be found at http://texassuperstar.com/.

Sources: Robert Burns, Dr. Larry Stein, Dr. Brent Pemberton, David Rodriguez