Cold-hardycitrus is citrus with increased frost tolerance and which may be cultivated far beyond traditional citrus growing regions.Binomial. Hardiness. Edibility. Notes. Trifoliate orange. Citrus trifoliata. These are some of the more coldhardycitrus varieties we offer. Its always recommended that you protect your citrus, at least until they become more established and mature. At that point they can be expected to be as coldhardy as they are going to be. Tough Citrus Farms is a coldhardycitrus grove in Whiteville N.C. specializing in rare citrustrees that stretch the boundaries of commercial citrus farming.Stan Specializes in coldhardycitrus, he currently grows and grafts some 40 different species of citrus till this day. Once you have selected your coldhardycitrustree, there are several keys to ensuring its survival. Select a sunny location that is sheltered from the cold northern winds with well-draining soil. If you are not container planting the citrus, plant it in bare, non-turf ground. Citrushardiness, which species survive as it freezes and gets colder.Often grown in our regions, citrustrees don’t all react to freezing the same way. This depends mainly on the variety itself, but how they’re being grown also has an impact on their frost resistance. Although it isn't the most coldhardycitrustree, it's the hardiest among grapefruit varieties. The fruit has a delightful blend of lemon and grapefruit taste, making it a must-have for grapefruit lovers residing in colder planting zones. Coldhardiness of adult trees. Citrushardiness table. USDA (U.S. Department of Agriculture) climate zones indicate thermal minima observed over the last 30 years. Climate zones in Switzerland range from 5a (coldest) to 9a (warmest). The age of citrustrees is important in coldhardiness. First year trees are more likely to experience freeze damage compared to older trees. PROTECTION. It is important to protect younger trees during the winter. Their smaller size makes them a breeze to move if you need to shift them for extra protection. Even if your home isn’t toasty year-round, these trees can keep producing. Start with a cold-hardy option and you’ll set yourself up for a thriving indoor citrus experience. ColdHardyCitrusTrees: CitrusTrees That Are Cold Tolerant.Protecting citrus from cold and frost Diy Christmas Lights, Patio Flowers, Hanging Christmas Lights, Indoor Greenhouse, Gardening Zones, Witch Garden, Banana Tree, Landscaping Tips. Fruit Quality vs. ColdHardiness.Low protection Citrus experiment in zone 7b France. This cold-hardycitrustree grows successfully in zones 8 to 11 in the ground. It can also be grown as a patio plant in any USDA growing zone. The cold tolerance of this tree gives growers in colder growing zones some extra padding time for getting this tree protected during winter. There is a coldhardycitrus guru (Bob Duncan of Fruit Trees and More) on Vancouver Island that specializes in citrustrees for the PNW. We have to contend with occasional freezing weather in the winter alone with a lacklustre amount of growing degree days in the summer.