Earlier this month I attended the Texas State Master Gardener Conference in San Antonio. The master gardeners had a new cold hardy satsuma, “Orange Frost”, available. This satsuma variety will not be commercially available until 2014.
What makes Orange Frost cold hardy in places like Austin is that unlike most satsumas, it is not grafted. So if a hard freeze in Austin kills the top growth down to the ground, the re-growth in the spring will be true to variety. Even with its extra hardiness, I will still mulch the roots heavily in the winter and cover the entire plant whenever the temperature dips below freezing.