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Fertilizing Hemlocks

The right food, at the right time, makes all the difference to an evergreen


What's the best product to fertilize hemlocks? What time of year
should I do it?

–Mark, Macon, Georgia


Roger Cook replies: Hemlock will benefit from any fertilizer designed specifically for
evergreens. You should consult your local garden center to see what they
have available, stressing that you want to fertilize evergreens
specifically. Some products are designed to be spread on the soil and
work themselves in. I like to take a pitchfork and punch a series of
holes in the ground, then spread the fertilizer so it will move down
into the soil. Another method is to use a bar to punch holes 8 to 12
inches deep into the ground and mix the fertilizer down into each hole.
Remember that main feeder roots are not found close to the trunk of
the tree. Tree roots spread out from the trunk to beyond the drip line
of the branches, so concentrate your fertilizing in these areas. Also,
remember to use just the amount of fertilizer recommended on the bag,
not more. Personally, I like to fertilize from October 15 on until the
ground freezes. This way the fertilizer will be available to the tree in
the spring when it is flushing out new growth. Finally, while working on
hemlocks remember to inspect them closely for woolly adelgid aphid. This
pest is much easier to deal with when found early, and if you do find
the adelgid, call a certified arborist to treat it.


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