Nerium (Oleander) tolerates a wide variety of soils as well as a maritime climate but requires full sun. Established oleander plants have an extensive root system and are drought-tolerant, but container plants need lots of water.
More Information About Nerium
The genus Nerium is a monotypic (just one species, Nerium oleander) evergreen shrub that is native to Asia, North Africa, and Europe. Nerium oleander is in the same plant family as vinca (periwinkle) and mandevilla, and you can see the family resemblance in the brightly colored, flared, tube-shaped flowers. The genus name nerium comes from the Greek "nerion" (wet) and is related to the Neriads, fairies that inhabited the ocean. Nerium grows abundantly in wet places along the Mediterranean coastline. The name oleander comes from "Olea", the genus name of olives, whose leaves are similar. Oleander leaves are very toxic, so deer leave them alone.
Tips for Growing Oleander
We spend quite a bit of time looking for cold-hardy forms of plants that should not survive here, and oleander selections have provided some interesting results. After our -9 F (-23 C) winter in 1984, we were able to find three colors of oleander growing locally that had survived the freeze. While they may show foliar damage after severe winters, these oleander can be cleaned up by pruning and will resprout quickly in spring.
It is important to establish oleander plants early in the season in Zone 7, and remember that planting in microclimates (warm pockets) will also help with hardiness. Oleander tolerates a wide variety of soils as well as a maritime climate but requires full sun. Established plants have an extensive root system and are somewhat drought-tolerant, but container plants need lots of water. Although it can grow to 20', most people trim oleander to a 6-10' shrub.
Please note that all parts of oleander are toxic. The sap of the plant will cause a skin rash, and a child that eats just one leaf can die from the poison. Even the smoke from burning the branches is deadly.