In article , "Mike LaMana"
fake@MikeatHeartwoodConsultingdotnet wrote:

I am no fan of chemicals - by a LONG shot - but I respectfully disagree. It
is most possible to bring declining flowering dogwoods around. The disease
organism seems to be on the decline in many parts of the east in native
woodlands. I am guessing that there may be a hyporvirulizing agent that
attacks the fungus, as is often true of American chestnut blight.

There is no cure or effective treatment for dogwood anthracnose. However,
infected trees given ideal care are stronger at fighting off the cyclic
attacks this disease makes on the trees, worse in years with heaviest
rainfall. These are the efforts that will have some positive effect on the
infected tree:

1) Careful watering during droughty months.

2) Perfect drainage during rainy seasons.

3) Mulching to limit its watering needs, starting one foot away from trunk
extending to drip line or further.

4) Avoiding overhead watering & whatever else it takes to keep the leaves
dry more often than wet.

5) Protection from bark impacts or injuries

6) Maximizing air circulation around the tree by having no other trees nearby.

7) Persistant removal & careful discarding of limbs & twigs showing signs
of infection.

8) Persistant removal & careful discarding of fallen leaves.

9) Avoidance of fertilizers, or if used at all, lowest-nitrogen fertilizer
once a year only, in spring. Sterile manure compost would be better.

10) Locate tree in sun. Despite that dogwoods like shade, alas so does the
anthracnose, & the tree will adapt to too much sun more easily than to an
aggressive flourishing of its chronic infection.

11) Religiously remove all brown leaves & discard carefully; diseased
leaves frequently adhere to the tree year-round spreading the disease
through to the twigs.

12) Never include dogwood leaves or twigs in the mulch.

13) Planting only low-water-use pernnials in the vicinity with the
dogwood's needs exclusively in mind.

These methods adhered to strongly enough can mean a diseased tree will be
attractive in more years than it will be unattractive. It will, however,
still be a sick tree, & more prone to insect attack & other diseases.

A large tree, or a tree in the wild, will be impossible to assist to the
fullest potential unless you really can crawl up into the highest branches
on a regular basis to remove diseased leaves & trim diseased twigs & do
everything else a high-mainteance sickly tree requires. Trees not
rigorously cared for die within three years. With care, this can be
extended to ten years. With a hardy hybrid, much longer.

Dogwoods may look very nice in alternating years; seeming improvement in a
given year is invariably an illusion.

Non-organic chemical treatment with an array of fungicides have never
proven to be particularly effective. Persistant use of fungicides
occasionally helps keep the leaves from splotching so early in the year,
without otherwise slowing the progression of the disease, & with the bad
side-effect of lowering the fungal component of beneficial microorganisms
thus hastening rather than retarding disease in the given tree. But in
some years, properly timed use of fungicides will at least give the tree a
better leaf look. Craig R. Hibben, a plant patholigist undertaking
special studies of dogwoods & chestnuts, made a list of 8 points similar
to mine above of what to do to lengthen the life of dogwoods. He left OFF
the list the use of fungicides.

While some resistant hybrids are on the market, none of them are all that
resistant, though better survivors with less maintenace if well positioned
in a very sunny uncrowded setting.

The best hope for the eastern dogwood are the descendants of the surviving
trees after mass die-off of dogwoods in Catoctin Mountain Park. These are
the first & so far the only truly resistant C. florida stocks in
production, but not yet widely available except to parks & forest areas
where the species is being reintroduced after losing nearly their entire
populations of dogwoods. Eventually the resistant strain will reach
gardeners. Other resistant forests are being monitored in the northeast;
it is beginning to not look hopeless for the eastern dogwood. Hope for the
western dogwood is still not very good. However, after forest fires in
British Columbia, the western dogwoods made an unexpected comeback that is
not yet thought indicative of lasting improvements, but Nature may provide
resistant wild trees for the western species given time.

When the disease progresses to blistering the trunk it is time for grief
counselling & professional removal of every part of the tree that is above
ground, including thorough cleanup of the sawdust scattered by the
chainsaw. I would not at this time in history plant a native dogwood tree.

-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"
Visit the Garden of Paghat the Ratgirl: http://www.paghat.com