USDA Plant Hardiness Zone 3
Gardeners in USDA Plant Hardiness Zone 3 live in the northernmost regions of the United States, along a narrow band that extends along the U.S.-Canada border and into Alaska. Representative geographical regions include parts of Montana, North Dakota, Minnesota, Maine and Alaska. The climate is characterized by long, cold winters and short, warm summers with average winter low temperatures falling between -40 and -30 degrees F. Some plants that may survive these temperatures will not necessarily thrive in this climate.
Plant choices for Zone 3 yards and gardens include:
Trees
Many Native American deciduous trees or their hybrids are superior performers in Zone 3, such as:
• American Red Maple (Acer rubrum). A colorful North American native tree that has vibrant red fall leaves, and even reddish new growth on twigs, stems and leaf stalks. Red maple is very cold-hardy and tolerant of wet soil.
• October Glory Maple (Acer rubrum 'October Glory'). October Glory is a cultivar of the Native American red maple tree. It grows to 50 feet and has a rounded form with reddish-orange fall foliage. Its tolerance for wet soil makes it suitable for rain gardens or for planting along river banks.
• Autumn Blaze Maple (Acer freemanii 'Jeffersred'). Autumn Blaze Maple is also commonly called Freeman Maple. It's a hybrid cross between American Red Maple and Silver Maple, having the best characteristics of each parent plant. This fast-growing maple is sturdy with a sound structure that isn't compromised by its rapid growth.
• Autumn Purple Ash (Fraxinus americana 'Autumn Purple'). The largest of the Native American ash trees – growing to 60 feet tall – Autumn Purple Ash is so-named because of its fall leaf color, which is yellow with purplish shading.
Berries
Packed with a healthy punch and easy to grow with minimal maintenance, these berries are hardy in Zone 3:
• Lingonberry (Vaccinium vitis-idaea). Lingonberries grow on small evergreen shrubs that grow only 12 to 18 inches tall, producing two harvests each year. They look like a cross between a blueberry and a cranberry, and they're packed with anti-oxidant health benefits.
• Stevens Cranberry (Vaccinium macrocarpon 'Stevens'). You don't need to provide boggy conditions to grow this Native American berry. Plants grow as an evergreen groundcover in moist soil.
Citrus Trees
Citrus plants are not hardy in Zone 3; they need the warm climates and abundant sunshine that warmer, tropical climates provide. But skilled Zone 3 gardeners with heated greenhouses, solariums or sunrooms can try their hand at growing some citrus plants. Climate-controlled growing environments (with plenty of sunshine) make it possible to enjoy:
• Meyer Lemon (Citrus x meyeri). A hybrid cross between an orange and a lemon, Meyer Lemon is easily grown as a potted plant.
• Key Lime (Citrus aurantiifolia). Key Lime is another citrus plant that is adaptable to container growth. These limes are smaller than the Persian limes sold in supermarkets -- they're the traditional limes for making Key Lime pie.
• Nules Clementine (Citrus clementina 'de Nules'). Another citrus plant that can be grown in containers, Nules Clementine is a dwarf tree that grows typically to 8 feet. The fruits are seedless and sweet for snacking.
• Nagami Kumquat (Fortunella margarita 'Nagami'). The unusual fruit can be eaten whole without having to remove the peel. The Nagami Kumquat is also a beautifully ornamental plant that is covered with small orange fruit.
Ornamental Tropical Plants
These tropical plants, which are not hardy in Zone 3, can be enjoyed outside during warm weather as potted plants to give a tropical touch to a cold-weather climate:
• Sago Palm (Cycas revoluta). Easily grown in containers, Sago Palm is a beautiful houseplant. Gardeners can move Sago Palm (in its pot) outside during warm weather in the summer and protect it during the winter by growing it indoors, or they can enjoy it year-round as a houseplant.
• Dwarf Cavendish Banana (Musa acuminata). This scaled-down version of a full-sized tropical banana plant is a beautiful potted plant. Although it takes a long, warm growing season to produce bananas, which can be done in a heated greenhouse, Zone 3 gardeners can enjoy it as a tropical foliage plant, potted on the patio in summer and in front of a sunny window in cold weather.