I had red that Thuja occ. has toxic essential oils (I think it refers mainly, but not only, to thujone, which are not only toxic after taking oraly, but also after inhalation). It has been adviced to get rid of those plants from the garden, since they secrete oils nearby them. My question is - is this true? Is secretion of plant high enough to couse problems? I assume one small plant would be ok, but since their often grow as high, thick and long hedge, there must be high concentration of essential oils around them and polluted air will be transferred by windows to the house. It has been also said that bees, birds and animals don't like thuja occ., but it is liked by ticks.
I am aware of thujone from other herb studies. I also grew up with one of these trees, we called it simply Arborvitae, outside within a dozen feet or so from two different bedrooms' windows. Right next to it was a Pyracantha, the precise species of which I don't know. Lots of birds, squirrels, natural habitat with introduced garden plants around the house. The Pyracantha is important to mention because it was always popular with the birds. There was no declination of the habitat with the location of Arborvitae, save less grass cover. I would guess it is allelopathic at least within the range of the roots. While it may be good to know what the active principles of a given plant are, it seems to me that we now worry too much about minor things in botany and not enough about the more pervasive toxic plants. I do not mean to belittle your concerns, but of all the plants I have banned from my gardens for various reasons, Arborvitae, Thuja occidentalis, is not one of them.
The oils might be toxic if you eat a few kg of the foliage, but you won't be harmed by breathing in the minute amounts that disperse into the air. No need to worry at all.
I understand that if ones has like 3 plants somwhere in the garden there is no problem. But if we talk about like 50 plants a couple of meters nearby windows and every one produce some oil into the air, concentration in the air might be not that low and a person will not be breathing in the minute, but 24h (in summer at least).
You could live in a forest of them (and people often have done!) and you'd still have no toxic effects. Even running a hedge trimmer over them won't release anywhere remotely near enough to be toxic. It'll just smell nice. Stop worrying about nothing!
Arborvitae are not nearly as dangerous as... peanuts. Jimmy Carter, beware! But alas,if we banned all nuts, these pages would be humorless.
