Boxwood and beans: Learning how to handle poisonous plants

By Helga Panten Feb 15, 2010, 3:08 GMT

Berlin - People who have learned how to handle wild, cultured and garden plants that contain poison can take pleasure in growing them in their homes and gardens.

Many of them serve well as decorative plants, medicinal herbs and even as food. But a careless approach to them is ill-advised particularly when there are children around.

One of the most beloved vegetables - the bean - is in fact poisonous. It contains an ingredient that can induce vomiting, palpitations and seizures. Potatoes also count among poisonous plants. Nevertheless, both vegetables are safely consumed.

The puzzle is solved by the following: The poison in beans disintegrates when they are heated leaving the cooked beans free of the toxin. The poison part of a potato is green, which they get when they are stored in too much light. Thus, any green bits on a potato must be thoroughly peeled away.

Potatoes and beans are the most striking examples of how people through the generations have learned how to handle poisonous plants without exposing themselves to any danger. Even if people were to reject having in their homes and gardens such favourite plants as daffodils at Easter, poinsettias at Christmas and tulips, snowdrops, cyclamen, delphinium, foxglove at other times of the year there would still be poisonous plants in the forest and in gardens.

Living without ever having contact with a plant that has a poisonous substance is therefore hardly possible and also not necessary if a few simple rules are taken to heart.

When buying a plant, whether for the garden, windowsill or a window box, write down its name or even have it stamped into a tag that remains on the plant and ask the sales clerk whether the plant is poisonous. If it is, a few other questions logically follow, namely which parts are poisonous and how should the plant be handled.

Usually, washing the hands thoroughly after handling the plant is enough. This removes not only any dirt, but also all plant juices with any possible poisons in them. When hand washing is consistently maintained, the danger presented by the beloved boxwood with its highly poisonous buxin, delphinium with its alkaloids and oleander with its oleandrin is gone.

But simple hand washing isn't enough when it comes to the plants in the aconitum genus such as monkshood, which contains the toxin aconite, and the heracleum genus, such as hogweed or cow parsnip. Gloves must be worn when these plants are dug up, transplanted or cut back. Areas of the skin that could come in contact with the cut leaves and stems must also be covered. The toxin aconite in the juice of the monkshood can be absorbed through the skin or the intestinal tract.

Special caution should be taken in gardens where children play. Poisonous plants such as monkshood, foxglove and the genus laburnum, also known as golden chain, which has pea-like fruit and conspicuous pods, should be planted or let grow in a garden only after children are old enough to know they shouldn't eat or touch them. These temptations can be lowered by removing their berries. In general, children should be taught to stay away from plants in the garden and neighbourhood that can make them sick.