Containers

• The secret to healthy, well-proportioned evergreen patio trees is choosing the right containers. Pots with diameters equaling their heights offer the greatest root insulation. Light-colored pots cool roots by reflecting sunlight. A penthouse patio in windy Chicago may demand heavy clay containers for stability. Frost-tender evergreens need lightweight pots to ease the move indoors for the winter.
  
  

Growing Medium

• Containerized patio evergreen trees need an organically rich, loose, compost- and soil-based growing medium. Container life limits their roots' access to moisture and soil nutrients. Regular watering and slow-release fertilizer applications are essential for their health. All pots should have drainage holes. Excessively wet soil encourages root rot and other fungal diseases.
  
  

Conifers

• Mugo pines (Pinus mugo) typically stand from 5 to 20 feet high. The pyramidal Tannenbaum cultivar reaches up to 10 feet. It tolerates U.S. Department of Agriculture plant hardiness zone 2 winters, and temperatures flirting with minus 50 degrees Fahrenheit. Dense branches of deep-green needles make it suitable as a patio Christmas tree. For a vertical accent, consider the Rocky Mountain juniper (Juniperus virginianae) Skyrocket cultivar. This patio tree matures to a 12- to 15-foot high, 2-foot wide column. Its tightly packed, upright branches of silver-blue needles contrast well with darker trees. Skyrocket withstands winter temperatures to minus 30 F.
  
  

Magnolias

• Coconut magnolia (Magnolia coco) trees grow wild southern China's tropical region. In the United States, they tolerate winters in hardiness zones 9 and above. The 6- to-8-foot tree's nocturnal ivory flowers fill patios with fragrance from sundown into the morning hours. Glossy, green foliage adds to their appeal. Little Gem, a large-flowered magnolia (M. grandiflora) cultivar, has reliable cold tolerance to zone 8. It needs 20 years to achieve a 15- to 20-foot height. Its fragrant, white late-spring flowers display well against lustrous, green 5-inch leaves. The 4-inch blooms produce showy, conical seedpods. The pods open in fall to reveal red seeds.
  
  

Fruiting Trees

• Blooming evergreen tea olives (Osmanthus fragrans) perfume their midfall to early spring surroundings with intensely fragrant white flowers. The 10- to 12-foot trees' blossoms open beneath their oval, shiny green leaves. They give way to clumps of small, blue-black fruit. Meyer's lemon trees (Citrus x meyeri "Meyer") bloom all year in mild climates. The 6- to 10-foot trees' white, sweetly scented flowers produce juicier, sweeter lemons than most commercial lemon varieties. Both zone 9-hardy trees overwinter indoors in colder areas.