Evening star., 1950-06-11
Farm und.Gorden
Sowdust Can Be Used ProfitobIy
For Soil Conditioner and for Mulch
BY Wilbur n. Youneman
Cerden Editor

= E0tIoB
added expense, but 1t Is not lost
as the dying bacteria release it
to the growing plants.
Nitrogen for the bacteria may
be supplied In many forms. any
one of which will serve. Poultry
and stable manures are excellent.
also cottonseed, peanut and soy
bean meals (organic) mixed with
the sawdust and either ammonium
sulphate, nitrate of soda, or a
mixed fertilizer such as 1864
(inorganic). Inorganic materials
may wash out before being taken
up by the bacteria, unless fed in
moderate amounts at regular in
tervals.
Some gardeners use o mixture
Of the two types-cottonseed meal
and ammonium sulphate-and in
corporate them into the sawdust
before application. Others apply
the sawdust and add the nitro
genous materials. The results are
about the same.
When handling sawdust in ton
lots the following materials may
be added:
For Erieaceous i For General
Partially rotted
sawdust ---- ton Ton
Ammonium
mes. sS pound: pound: S 80 SSsSRs: BOUNDS
supse9qpsosph.t. s9Pf g Dounaa Pouna: 80 Soands
Oak and chestnut sawdust re-
quire more lime to neutralize
the acidity than do pine. tulip. etc.
MuIching Technique.
Most gardeners find that
mulching around the plants Is
more satisfactory than covering
the entire bed with q layer 2 to
4 inches deep. If nitrogen ma
terials were not mixed with the
sawdust before using as mulch
it may be added gradually, using
the color of the plant foliage to
determine If an adequate supply
is being furnished. Excessive use
of nitrogen will also show up in
the luxuriant foliage and the
abundance of new growth. This,
however, can be overdone since
woody plants should make their
growth in the spring and the wood
should mature before cold weather
arrives in the fall. For this
reason, it is advisable to refrain
from using the slower-acting
nitfogens (cottonseed, peanut
meals after the first of June.
In the perennial border it is
advisable to avoid placing the
sawdust mulch close to the
crowns of plants subject to crown
rot. Plants such as iris and
delphinium are likely to suffer
from disease.
The mulch may be left on the
surface of the bed through the
winter or it may be mixed into
the soil to improve its texture
and water-holding capacity. If
left on the surface it tends to
keep plant roots active longer
than may be desirable. For this
reason in the fall it is advisable
to work the mulch into the soil in
the perennial border and rose
beds. When used around azaleas
and narrow-leaved evergreens it,
seems to benefit them most if
left on the surface. 4
How Coarse and How Much.
For soil imorovement before
placing large shrubs and trees.
a sawdust mixture containing
nitrogen, lime and phosphate
should be well mixed with the soil
to a depth of foot or more.
There may be some possibility of
OVERRIDING the addition of sawdust
but from present information up
to a so per cent mixture appears
safe.
There is one point on which
information is missing. Plant
roots require air and a deep
mulch could affect their air sup
ply. A New York gardener de-
scribing his use of SawduSt
mulches advocated the use of
coarse material such as may be
obtained from a planning mill.
1t would seem logical to use either
a thin layer or coarse material
when mulching shallow-rooted
plants such as azaleas, dogwood
and laurel.