While Yews are known to be poisonous to humans and animals I've not seen that they may be growth suppressing, allelopathic.

What are the soil conditions in that area?

Any chance the Yew is using all the available soil nutrients so the other plants cannot get any?

Have you had a good reliable soil test of that soil done?

kimmq is kimmsr

yesw are conifers .. and conifers are trees ..

and growing under any 50 year old tree can be tricky ...

root competition for water ... is a prime consideration ... as well as density of the canopy and rain actually getting down under ... especially on a plant that has been sheared for decades ...

its a veritable desert under some of these things ...

all that said.. all you can do is try ... and insure proper watering ... as you well know.. hosta are water hogs..

ken

Actually, once hostas are well-established they are quite drought tolerant and work well in dry shade. They are often recommended for that situation although they will grow larger and more vigorously with regular water.

"water hogs"?????......not so much :-))

Pat, I recall that yews yield a chemical which was under consideration as a cancer-fighting drug; there might be a connection.

And now, for a light-hearted aside. There is an (East) Indian tale of a husband who wanted to visit his parents - a journey of 5 days! His young wife, fearing that he might not come back to her, consulted her Guru. Before the guy set off, his wife made him promise to sleep under a tamarind tree on his outward journey; and under a neem tree when he would return. Apparently the tamarind exudes toxic vapors at night; which made the traveler unwell. By the fourth morning he was so sick that he decided to return home. Each night he dutifully slept under a neem tree. These exude beneficial vapors at night so the traveler woke up feeling more refreshed. The unknowing husband associated increasing distance away from his wife with injury to his health; decreasing distance improved his well being. And so he resolved never to leave his wife again.

One can draw many conclusions from this story. Mine is, "To be a good Guru, first learn some botany."

The drug is Taxol, it is routinely used for cancer treatment (primarily breast and ovarian cancer) and is extremely successful. Probably one of the biggest breakthroughs in natural cancer treatments in the last century.

But the chemical is only derived from the Pacific yew, Taxus brevifolia. These yews are not typically found in cultivation, remaining primarily in their natural environment and not even all that many there. At one time, it was anticipated this species would become endangered due to the harvesting for medical purposes until the drug was able to be synthesized.

Even though these types of yews are not widely planted (and seldom much away from their coastal environment), they still are not considered to have any allelopathic properties.