Re: peat moss
Nancy Stedman wrote:
> I believe that the use of peat moss killed two rhodos of mine several years
> ago. Even though I watered them in a drought, they developed a fungal
> disease and wilted overnight. When I dug them up I discovered that the peat
> moss they came in (from the nursery pot) had never gotten wet. I haven't
> used peat moss since then.
>
> You are far, far better off using compost.
>
> Nancy S. (NYC, zone 6B)
>
> >In a message dated 03/18/2001 9:14:00 AM Central Standard Time,
> >msgardens@HOTMAIL.COM writes:
> >
> ><< that there were still places that were as
> > dry as can be, where I had not mixed enough to moisten the peat. Any ideas?
> > Lynn >>
> >
> >
> >Peat moss should not be use in new tree or shrub plantings.
> >
> >Paul
> >
I will try to answer what can most likely kill rhododendrons. I recommend Harold
Greer's book on Generally available Rhododendrons for many reasons. I have
discovered with time that some rhododendrons are a lot tougher than expected.
This has not been well documented anywhere that I know. The converse is also
true that some rhododendrons will not survive under your conditions even if you
have been assured that it will. My advice is to try some other plant if you
continue to have difficulties with the ones you try. There are some truly rock
hardy species and hybrid rhodos that are spectacular. Micro climates can be
everything. I have one very old, greater than 15 years, rhodo called "Seta"
which should have died shortly after it was planted because we had a major early
harsh frost in 1990 here.
I can assure you that the use of peat moss at least the stuff you find in most
stores is a disaster around rhododendrons. Here in the Seattle area I murdered
more than I care to think about before I finally realized that peat moss and
rhodos and probably many other things are not compatible. The problem is that
peat moss holds the moisture in the roots and the plant either drowns or dies of
root rot. There are some horticultural grades of very coarse peat moss that is a
perfect material for starting small plants and rooting cuttings.
Many plants of which rhododendrons are one example require very good to very
sharp drainage. The problem is how do you achieve this goal. Puget sound soils
are glacial till layered over with forest duff, if it was left by the builder
which is unlikely. The point is that many of the soil structures drain quite
well but some don't. As in any garden situation you have to try various things
as amendments. Here one of the best is wood chips from tree cutting and pruning
operations. It will for a while greatly increase the porosity but later breaks
down. Ultimately crushed rock or pea gravel are ideal to mix with existing
soil. The water still has to have somewhere to go after it drains past the rhodo
roots. Raised beds, or mounds work well to achieve this drainage. Many
rhododendron species in the wild live as epiphytes on trees or rocky crags.
Rhododendrons and their family members breathe oxygen from the roots. The crown
of the root ball has to be above the original soil line. It is wise to lightly
mulch the ground out to the leaf line to keep the roots from being scorched on an
unexpectedly hot day. As time goes by and the plant becomes more attached to its
site continuing to add mulch materials is beneficial. Eventually it is
recommended to remove some duff near the main stem(s) to ensure free air
circulation under the mantle of the plants leaves.
Many rhododendrons do not like the hot afternoon sun. It is a good idea to pay a
lot of attention to a newly planted rhody. If in the morning the leaves are
hanging down the plant is either too dry or drowning. Gentle watering every
several days will provide some indication of which is the circumstance. If the
leaves lift upward early in the morning then the plant is fine. If not at the
earliest opportunity pick the plant up from the ground. If the roots are bone
dry soak the plant in a bucket of water for 1-2 days being careful not to drown
it. If the plant has an adequately wet root mass something is seriously wrong
and most likely the plant will die no matter what you do. There are emergency
procedures but I do not know what they are at this time. Contact a researcher at
Oregon State U., Corvallis, Oregon for possible advice.
Many plants including rhododendrons have symbiotic relationships with soil
micro-organisms both fungi and bacteria. It is believed that the balance of
these organisms is critical to the long term survival of rhododendrons. To the
best of my knowledge no systematic study has been made of these relationships.
There are some plants that do not survive easily away from their native
environment. I am convinced that someone is going to have to bring these soils
back with the seed.
Please feel free to comment on the above. These are my observations over many
years and from conversations with the experts I have lucky enough to meet. Every
year I murder plants that I prized so I try again and try to be more observant.
One technique that I have used with limited success is to move an ailing plant to
a sharp draining soil mixture. Sharp draining is defined by myself to exist when
the soil is lightly wetted after watering and most of the water just runs though
the pot. Let the plant get nearly dry before watering again, that could be
sooner than you expect. I have been attempting to grow every type of
rhododendron, from rock hardy to tropical varieties and there are no simple rules
each plant has its own peculiar needs.
I have found my jury-rigged green house to be a great asset with all types of
plants when disaster strikes. It does not have to be expensive to build one.
--
Walter Brooks Jr.,
Novice rhodomaniac of 25+ years
ARS Life Member.
Retired chemist and materials scientist
29814 11th Ave SW
Federal Way, WA 98023-8210
253-941-3854
c1w2brooks@qwest.net
