Fred Hebard is the Director and Staff
Pathologist at the Meadowview Research Farm in Virginia
In general, we only apply Miracid to young trees in
their first or second leaf. We fertilize older trees by side dressing
with granular fertilizer having a similar analysis, 20-6-6. Miracid
is 30-10-10. The different numbers are not critical since the ratios
are approximately the same. The important factor is the total amount
you apply per unit area.
Regarding the total amount of fertilizer to apply,
some people have made the mistake of continuing to fertilize older,
larger trees with small amounts of Miracid. Half a gallon of Miracid
is a lot of fertilizer for a small tree one-to-three feet tall. It's
an insignificant amount for a larger tree ten to fifteen feet tall.
It's more accurate to apply the fertilizer as pounds of nitrogen,
phosphorus and potassium per unit root area.
The root area of a tree is approximately delimited
by the size of its crown. A one-year-old seedling might have a root
area of one square foot. In contrast, a three-year old seedling might
have a root area of 100 square feet. To apply an equivalent rate of
Miracid to the larger tree, instead of 0.5 gallons you'd have to use
50 gallons!…
When applying granular fertilizer, we only have
time to apply it twice a year, so we most often use rates of 200
pounds of nitrogen and 60 pounds of potassium and phosphorous per
acre. We apply granular fertilizer in mid May and late June. To save
time, we broadcast that over the entire orchard rather than just side
dressing the trees. We also vary the amount of potassium and
phosphorous depending upon the results of soil tests and vary the
type of nitrogen depending upon soil tests, in consultation with
specialists. We also sometimes apply lime as indicated by soil tests.
My primary monitoring of whether our fertilizer
program is OK is to look at the trees. I look for leaves being a
uniform dark green, as opposed to light green or yellow or spotted or
mottled. I look for healthy growing tips and a long stem between
leaves, about 3 to 6 inches. If something doesn't look right, then I
try to find out why, asking questions such as: Does the tree have
blight? Are there other pathogens or insects attacking the leaves,
twigs or roots? Is there herbicide damage? Is the soil loose and well
drained? If none of these factors appear to be causing the damage,
then we run soil tests and foliage tests to look for mineral
deficiencies and try to remedy those. I also look for late hardening
off in the fall and early leafout in spring."  Use
a 3
Gal Tree Pot from
Stuewe to
promote long tap root growth and SunGro Southern Perennial Mix (SPM)
with micronutrients and drains well.
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