In article ,
(Dennis) wrote:

I have encrustations on several small trees and bushes and wonder if
anyone might identify them and advise on how to get rid of them.
Pictures are on the following web site:

http://freespace.virgin.net/penny22.ogden/testB

Many thanks in anticipation,
Dennis

Lichens are harmless & attractive & even do trees & shrubs a good deed by
keeping them from being sun-scorched or dehydrated during difficult dry
spells. Your text with the pictukres suggests you think the rowan tree is
being killed by the "encrustation" but you'll have to look elsewhere than
to lichens for the cause. It also looks like it may have undergone an
unnecessarily extreme pruning.

The diseases to which rowans or ashes are susceptible tend to effect the
appearance of the leaves. As you mentioned no such feature, I suspect
they're not ill, but old. You could have the soil tested to see if there
is some deficiency developed over time. Rowans usually tolerate even
ruined soils, but can occasionally prove to be alkaline sensitive if grown
in lawned areas that get so many recurring lime treatments that some
trees finally just decide life's not worth continuing. Rowans aren't as
apt as some trees to have this sensitivity, but everything has its limits,
& something close to neutral pH serves rowans best.

The main thing, though, is that rowans do not have particularly long
lives. It's hard to judge the size of that trunk without something by it
for perspective, but it looks like quite a large old tree as rowans go, so
you may just be seeing it going through a natural decline. You can assist
it by keeping grass away from the roots as far as the dripline (grasses
secrete growth suppressing hormones so as to out-compete other plants; you
could plant shade-tolerant lily grass, cyclamens, shade plants around it
safely, but always starting with small things so you don't have to dig big
holes & perhaps damage the rowan's roots). Also make sure it has a bit of
water during dry spells, & give it slow-release mild fertilizing each
autumn. And keep lawnlawn fertilizer away from the dripline. These
measures could help delay the inevitability of removing trees that are
approaching the end of their lifespans.

-paghat the ratgirl

--
"Of what are you afraid, my child?" inquired the kindly teacher.
"Oh, sir! The flowers, they are wild," replied the timid creature.
-from Peter Newell's "Wild Flowers"
See the Garden of Paghat the Ratgirl: http://www.paghat.com/