Next
to Pruning, Watering is the quickest/most decisive way to affect plant
growth. Too much: too much growth and too long growth, root rot,
drowning, death (more plants are killed because of overwatering than from
underwatering);
-
A little more than optimal: stimulation of
new growth;
-
A little less than optimal: maintain growth
on established plants; stimulate some plants to produce flowers;
-
Too little: new growth withers, dehydration,
death.
Learn individual watering needs, Amount and Frequency, the “Five S’s”:
-
Season
= air temperature, humidity, dew point;
-
Siting
= amount of direct sun/shade, wind, reflected light, ground moisture/cover;
-
Size
=
pot and plant, small/medium/large, shallow/tall, partly glazed/unglazed,
weight when watered/dry;
-
Soil
=
grain-size, percentage of organic or other water-retaining material, texture
& color when watered/dry;
-
State
= newly transplanted or root pruned/established, newly pruned, healthy/sick.
Allow the soil surface to be dry and even a slight wilting of leaves showing
on some varieties before watering again, then water deeply and thoroughly.
Quality: right from the tap (the worst); tap that has been sitting out
24 hours; sitting tap with a small amount of white vinegar added (1 tablespoon
per gallon at least once a month); distilled; pond/aquarium; Reverse Osmosis
(R.O.); rain (the best, but least likely to be gotten).
Watering can be done from the bottom using a sink or tub, good for just
a few plants. From the top using a hose or watering can, good if
you have several plants. Foliar, good to clean dust and dirt
off plants and cool the leaves, but best with distilled or R.O. so as not
to put salt deposits on leaves. Salt from tap water can build up
on pots, trunk and roots and possibly cause leaf burn in some plants.
Azaleas and bald cypresses can be killed by hard water.
Fertilizers:
-
The Big 3:
N
itrogen
-
P
hosphorus - Potassium (
K
)
are necessary, respectively, for Leaves & Stems - Roots & Flowers
- Overall Health and Hardiness.
-
Micronutrients: At least 15 other elements
in smaller quantities are also vital for the life of plants.
S
ulfur
and Magnesium (
Mg
) are the two most
important micronutrients.
-
Organic (less concentrated, slower acting,
complex with other substances, e.g., fish emulsion, bone meal, blood meal)
/ Inorganic (concentrated, quicker acting, simpler/purer chemicals, e.g.
MirAcid
®
or Grow Power
®
)
NOTE:
Bonsai is a continually evolving art, especially as practiced in a younger
location such as the U.S. There is some evidence now of potential
harmful longterm effects of synthetic commercial fertilizers in bonsai
soil mixes -- for instance, the buildup of salts that are part of those
fertilizers' composition. Based on our own positive longterm experiences
with these blends in this unique environment, we offer caution about quitting
their use just because it is recommended to do so elsewhere. This
is a subject which must be further investigated. As we get a clearer
picture of the best care for our desert growing trees we will include that
information here.
-
Full strength or Half strength or Gradual
release (i.e., Osmocote
®
or Grow Power
®
)
-
Urea-based nitrogen fertilizers are slower
released and safer acting.
When to apply? During growing seasons, not during dormancy, during
pre-flower seasons.
If air temperature is under approx. 70 F, fertilizer acts very slowly;
If air temperature is over approx. 90 F, fertilizer acts very quickly.
Keep a log of your fertilizer application and results, if only for a single
year.
Finally, the concept of "feeding the soil" as opposed to just "feeding
the tree" is one that needs further discussion in our circles. Stay
tuned.
See also:
"The
Limits of Fertilization" by Andy Walsh
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