"Oh, that won't grow here." How many times have aspiring gardeners had their hopes dashed by such a blanket statement? The fact is just because you don't see something growing in your neighborhood doesn't mean it won't. Oleander (Nerium oleander) is a good example.
Native to the Mediterranean region, this shrub has so much going for it. It's evergreen. It's easy. It's tough. It offers weeks of beautiful single or double flowers in a huge range of colors, including red, pink, peach, yellow, and white. The only thing that holds it back is tenderness to cold.
Because many people see oleander growing at the beach, they think it won't take frost. They are wrong. More than 25 years ago, I bought a small pink oleander at a garden center on Pawley's Island, South Carolina while on a family vacation. I took it home to Maryland. When I moved to Alabama, that oleander came with me. It's blooming this very day (see photo below). And I've learned how much cold oleanders can really take.
Twenty degrees. That's how cold it can get without causing any damage to flower buds or foliage. At 10 degrees, flower buds die and leaves get burned. At 0 degrees, the plant will probably die to the ground and then regrow. Because mine grows in a big pot, I take it inside the garage when night temps drop into the teens. But especially hardy selections, such as 'Hardy Pink' and 'Hardy Red,' do bend the barriers. I've seen an established, 10-foot tall, pink oleander in full bloom growing in front of a house in Moundville, Alabama. I know it's been there for years.
Growing conditions. Other than winter cold, almost nothing bothers oleander. Just about any well-drained soil will do -- acid or alkaline. Once established, it's very drought-tolerant. It also withstands wind and salt spray, which is why it's a favorite for beach planting. It needs little fertilizer. Give it full sun. Very few pests assault it, except for oleander caterpillars (see below).
Pests. Moths lay eggs on the undersides of the leaves. The eggs hatch into voracious bright orange caterpillars with tufts of black hairs. Severe infestations can defoliate a plant. To prevent this, spray your plant according to label directions with Bt (Bacillus thuringiensis), a bacterium that is harmless to people, pets, and most insects, but lethal to caterpillars.
Pruning. Oleanders can grow 10-20 feet tall if you let them, so here are some basic pruning guidelines. Prune these shrubs immediately after their flowers fade. This will encourage new, fresh growth and you may get more flowers. Older oleanders may get woody and bare at the bottom. Rejuvenate them by cutting off 1/3 of the oldest trunks at ground level in spring over a three-year period. Don't want to prune? Buy a dwarf selections, such as 'Turner's Carnival.' It grows only about 4 feet tall.
Where to buy. You'll often find oleanders for sale in local garden centers and nurseries. Top Tropicals is a good mail-order source.
Isn't oleander poisonous? Why, yes, the sap is. Despite this, hardly anyone gets poisoned, because the leathery leaves and stems are thoroughly unappetizing, unless you're an oleander caterpillar. The Grump did hear of Boy Scouts getting poisoned by toasting marshmallows over a campfire using oleander sticks for skewers. My expert advice? Don't do this.
Thanks to kellyv, mccheek, and cjewell for photos.