PRUNING YEWS -- CANCER RESEARCH: 30 November 2002
Neilma e-mails: "We have a self-seeded, rather strikingly beautiful yew tree. After pruning it over its lifetime -- about twenty years -- it is now overshadowing the garden and we really need the light and air back. When and how can we give her a hair cut."
R J Harris replies:
1) Being twenty years old, the yew tree may be pruned back in height by up to one third -- but by no more than that.
2) For the same reason, its side growth all the way round its girth can be pruned back by up to ten inches or 25cm -- but, again, by now more than that.
3) If the yew tree is located in a mild part of the country, it is best pruned in September at the end of the moon's fourth quarter. Then, it will lose the least amount of sap as the surgery is carried out and, consequently, suffer the least trauma. The key to this is the water table's level. It is at its lowest point and, hence, imposes the least upward pressure.
4) If the tree is located in colder regions, prune in April or May at the same moon time.
The head gardener explains: "The yew tree grows very slowly. So, it takes a very long time to recover from surgery. This being the case, it must not be in a frozen state when pruned, or must not enter into a frozen state just after being pruned. This is because freezing prevents healing. That leaves the tree vulnerable to disease and pest for a length of time that is longer than would otherwise be the case."
The yew was in the news about a year ago when it was found that chemicals extracted from it had a significance in cancer research. Neilma referred to this, indirectly, by asking where to send yew-tree cuttings for medical purposes (a question to which, having no knowledge, neither the head gardener nor I had an answer). However, Neilma was in touch, later, to suggest a visit to http://news.bbc.co.uk/hi/english/health/newsid_147000/147148.stm and to http://www.limehurst.com for information on this point and on the king disease and matters connected. I have visited, and have been much informed.
p 22 April 2004. Much more available than the chemicals in yew-tree cuttings are the chemicals in green and black tea. This is worth noting, because an American study published this month states that they can slow the growth of cancer cells in the prostate. Prostate cancer is edging its way to the top of the list of killer diseases for men. Of about 20,000 cases diagnosed annually, 10,000 result in death. Caught early, it can be dealt with successfully. Unfortunately, more often than not it is not treated until it has reached advanced stages, due to men's reluctance to take such an intimate problem to the doctor. At the beginning of the research, studies on animals suggested that common-or-garden tea may have anti-cancer-forming properties. The animals were fed tea, and were then found to have tea's anti-cancer chemicals in their prostates and associated tissues. The same was found to be the case in the prostate tissues of tea-drinking, afflicted men. It was found, too, that, in the presence of black- or green-tea chemicals, the growth of the cancer cells was slowed. The results were compared to those obtained from a control group of men who drank not tea, but carbonated drinks. The spread of the prostate cancer cells of these unfortunates was in no way reduced. Reportedly, the race is now on to produce and then to test capsules containing the tea chemicals in concentrated form. It is presumed that, if effective, the capsules will be taken as a benign, long-term, preventative measure -- much as supplements such as vitamin C or brewer's yeast are taken regularly at meal times to compensate for possible deficiencies in the food consumed.
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