Growing Range

• Only grow yellow oleander outdoors in U.S. Department of Agriculture plant hardiness zones 9 and warmer. Even in the chillier parts of zone 9, the shrub may be killed if a prolonged freezing period occurs each winter. It's best used in gardens only in the warm-winter areas of Southern California, the low deserts of southwestern Arizona, the southernmost tip of Texas, Hawaii, Puerto Rico and peninsular Florida.
  
  

Growth Considerations

• Yellow oleander remains evergreen, or nearly so, in regions where frosts never occur and winter temperatures do not drop into the 30 to 40 degrees Fahrenheit range. It can become a small tree 15 to 25 feet tall and equally wide, bearing its flowers intermittently year-round in warm conditions. Light frosts quickly kill back above-ground stem tissues so the plant must rejuvenate each spring. The shrubs only get about 5 to 8 feet tall and wide before the next winter.
  
  

Root Protection

• In regions where winters are frosty but mild, such as along the northern Gulf Coast or intermediate desert elevations in Arizona and southeastern California, protect yellow oleander. Mound sand 8 to 12 inches deep over the base of the shrub by early winter to shield the branch bases and roots from penetrating cold. While the sand berm may not be necessary for roots to survive in these areas, yellow oleander may not flower well if no buds on the lower parts of branches survive and sprout to rejuvenate the shrub in spring. Flowers from new growth will then appear in summer and fall.
  
  

Growing Conditions

• Always plant yellow oleander in a sandy or gritty soil enriched with organic matter. The soil must be well-drained and never flood. The more direct sunlight the better, as it keeps the plant heavily leaved and more compact in form. Sunshine encourages more flowering, too. Site yellow oleander out of windy garden spots to prevent branch breakage and severe winter dieback, especially in regions where winter lows regularly dip into the 28 to 32 degrees Fahrenheit range.
  
  In regions with cold winters -- USDA zones 1 through 8 -- that would kill yellow oleander, grow it in a container and move it indoors to a warm, sunny room. Bring it outdoors only when frosts no longer occur. The toxicity of this plant, along with its ability to grow quite tall, may not make it a practical long-term container plant to repeatedly move indoors and out over the years.