2336Re: [AZ] question:lichens
- Apr 1, 2005Jim
I'm sure that Steve Henning is correct when he says that lichens appear
on woody plants that have thin leaf cover. That's been my observation.
The question arises, "why is leaf cover thin?" If the plants are not
huge old things that have naturally slowed down their growth with age,
I suspect it's due to a poor growing environment, most likely poor soil
Essential to thriving azaleas and other rhodies are: 1) well aerated
soil, 2) proper pH, 3) a good balance of organic and inorganic
material, 4) adequate (but not too strong) nutrients, 5), adequate (but
not too much) moisture and 6) adequate light (for the particular type
of plant). All of these should be checked and corrected if necessary.
If you're not sure how to go about it, a state agricultural experiment
station can help answer #1, 2, 3, and 4. Other gardeners with plants
like yours can help answer # 5 and 6.
If the plants are not too far gone I suspect a "cure" will be found
here. If things are very far out of line, of course, it may be
necessary to move the plants to make the needed corrections. They may
then need to be "babied" for a while until they recover their health.
It won't be instantaneous but should be obvious as next year's growth
Concord, Mass. where the temperature today is about 60F (16C) and our
last 8 inches (20 cm.) of snow is disappearing fast. Warm rains and
maybe floods expected tomorrow.
On Apr 1, 2005, at 9:56 AM, S. M. Henning wrote:
> "JOT" <JimPatsy@...> wrote:
>> lats spring i purchsed a product to use in my vegetable garden and
>> in reading the label i found it could be use to control lichens.
>> the product "kop-r- spray" by "lilly miller".it contains 8% metallic
>> 'i tried it and am pleased with the results.( requires several
>> i don't have a photo of before but the first attmt is a couple of
>> limbs of the plant i treated.the sec photo is of the plant i plan to
>> treat this spring and will follow up with an after photo this fall.
> Why would anyone want to control lichens (Lichenes)? They are
> harmless. They derive their nourishment from the air, and generate
> by means of spores. A favorite theory of lichens (called after its
> inventor the Schwendener hypothesis), is that they are not autonomous
> plants, but that they consist of ascigerous fungi which grow
> symbiotically with algae. New Zealanders love wooden garden
> furniture that looks bleached and is covered with lichens. Lichens
> are almost as attractive as Spanish moss and just as harmless.
> Epiphytes are not parasites. They are pioneer plants that help
> recover severely damaged areas.
> Jerral Johnson of the Texas extension service published the following:
> "The effect of lichens on a tree are only slightly detrimental. The
> plants are epiphytes. That is they derive their nutrients from the
> air and not from the plant on which they are growing. Although they
> are not parasitized, literature reports suggest that lichens do have
> a slight negative effect. The main concern is that lichens give a
> tree an unkept appearance. Presence of lichens also is a good
> indicator of a thin tree canopy. This often leads homeowners to
> conclude that lichens are the cause and not the effect of thin
> foliage. The best control for lichens is maintain the tree in good
> condition. This will insure a dense canopy which will shade the limbs
> and reduce photosynthesis. Without photosynthesis, lichens are not
> able to manufacture food needed for growth and development.
> Copper containing fungicides are suggested as possible controls for
> lichens. Applications of Kocide DF for the control of ball moss, have
> been observed to control lichens for a short period of time.
> Currently copper fungicides are not approved for lichen control.
> Because of their limited affect on a plant, chemical control is not
> Cheers, Steve Henning in Reading, PA USA Zone 6
> Visit my Rhododendron and Azalea web pages at:
> Also visit the Rhododendron and Azalea Bookstore at:
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