The Madman And His Oleander

Oleander is an extremely poisonous plant. All parts are toxic – flowers, leaves, stems, roots, everything. It doesn’t grow in Zone 6. No sane gardener in Connecticut would plant this shrub. But remember, I’m not working with just any gardener, I’m dealing with a madman.

Discovery!

So, when he joyfully announced that he found a specimen, my reaction was, “really?” Let me explain. A few years ago, a friend of his was getting rid of a large collection of tender exotics. The heirs of his former employer weren’t interested in maintaining the collection. We drove to the top of Avon Mountain. When the madman saw what was available for the taking, his head exploded. After claiming a few large Euphorbias for his collection, he went around the corner of the house to look at the Oleanders.

His jaw dropped. There were four stately shrubs in gigantic pots. That’s when reason kicked in. Oleander is hardy in Zones 8-10. They need to be brought in over the winter. Even the madman knew that one was the limit. So, for the past three years, we drag the pot in to the étalier in the fall and drag it back out in the spring.

Rough Winter

During the winter, the Oleander is sheltered. Occasionally the temperature drops below 20˚. We throw water on it every now and then. Until this spring, it has seemed fairly happy – root-bound, but happy. But, this year Mr. Oleander dropped all his leaves and we almost pronounced it dead.

A bit of research convinced us that Oleander is a very forgiving plant. It withstands drought, salt spray and exhaust fumes. I guess that’s why it is used in landscape and roadside plantings in warmer climates. The state of California plants millions along highways. Our research introduced us to two very cool-looking moths that feed on Oleander: the Oleander Hawk moth (Daphnis nerii) and the Spotted Oleander Caterpillar moth (Empyreuma pugione). Neither moth is found in Connecticut, but the madman does like their looks.

Revival

So, the madman figured we couldn’t do any more damage to the plant. Maybe we could save it by splitting it apart. We rolled it onto a tarp and spent the afternoon pulling, cutting and sawing until the root mass slid out of the pot. Eureka! It looked like there was some life near the base of the plant. So, we sawed the root ball in half, severely pruned the top growth and ended up with two fairly nice selections.

You may be wondering why we bothered. Poisonous plants with beautiful flowers or curious foliage have always fascinated the madman. And, if a plant shows up on a list of deadlies, he gets the “I wants”. Oleander makes lots of deadly plant lists like this one. He’s been looking for Oleander for a very long time.

Nerium oleander

Oleander (Nerium oleander) is native to northern Africa and the eastern Mediterranean area. It is drought tolerant and thrives in a variety of soil conditions and environmental conditions, making it a favorite planting of southern highway departments. Hardy to winter temperatures of 20˚, Oleander thrives in USDA Zones 8-10. Here in Connecticut, that means dragging Mr. Oleander inside for the winter. As a houseplant, Oleander is happy in a cool, sunny window – with moderate watering. Or tuck it into a cool bright room and water sparingly – we just put it in the étalier next to the fig and hope for the best.

Summer Bloomer

In warm climates, Oleander blooms all summer – a definite plus for its desirability since the blooms are beautiful. Oleander cultivars are available in a wide variety of colors; some are more fragrant than others. Generally, the double varieties are more fragrant than the singles. The blossoms show up on the tips of new growth, so it is best to prune them in late winter before growth starts.

Folklore

There’s a real interesting story from Pliny the Elder about the Oleander and honey made from its showy flowers. Remember, we’ve already said that all parts of the plant are poisonous. Anyway, as the story goes, an invading army is moving into a town in Turkey. As a matter of defense, the locals put out jars of honey made from Oleander nectar. The invaders gladly snatched up the honey and gobbled it down resulting in the demise of the soldiers. Great story, huh? Except for an extremely interesting fact about Oleander flowers. They have no nectar. (Scholars suggest that it was a mis-translation of Pliny that credited oleander as the honey source – it was actually Azalea.)

Deceit Pollinator

Most flowering plants have a great relationship with pollinators. The pollinators move pollen around. In return, they get nectar. Not Oleander. From the pollinator’s standpoint, a visit to the flowers is reward-less. Oleander is a false pollinator, offering nothing in return for the work. Confused? A pollinator will visit several blossoms before abandoning the search for nectar. But he will go back to the hive and tell the others “Don’t waste your time.” I find it interesting that the fact that Oleander is nectar-less isn’t woven into an insect’s DNA to ward off future generations, but it’s not.

Getting back to the story of the poisonous honey, if there is no pollen, there can be no honey. But it makes for a good story and the madman says, “Never let the truth get in the way of a good story.” So, how do Oleanders produce seed? Pollen aggregates is the answer.

Clever Pollination

Most plants produce pollen in single grains. In order to ensure good germination, a lot of these single grains have to be moved, requiring a lot of visits by pollinators. Plants like Oleander are sneaky. Their pollen grains are clumped into aggregates held together by a sticky substance. Since pollinators don’t like to waste time and energy searching for nectar, they will visit several flowers on a single plant before declaring the plant useless. But, in these few visits, a lot of pollen has been moved so flowers do get fertilized, and they produce seeds that are easily carried by the wind.

Flowers

One of our new plants actually produced flowers, a bonus considering the severe pruning we did. We are hoping to have lots of blooms next year, but right now the madman is happy to have manageable Oleanders. If you have pets or young children, you might want to avoid this plant.

This fall we’ll be dragging two Oleanders into the étalier, and with a more manageable size, the madman is looking forward to dragging two out next spring.

But now, it’s time for lemonade.