Apply Fertilizer to Trees When it Cools Off

Q. How much fertilizer should I give my trees in the
landscape and when can I do it?

A. Apply fertilizer to established, winter hardy
landscape trees late in the season when temperatures have cooled down, trees
aren’t growing anymore but they still have leaves. This is called a late fall
fertilizer application and substitutes for a spring fertilizer application. In
the Las Vegas Valley this would be around late October to the middle of
November.

            Apply it
to the soil after an irrigation by using a sharpened, round nosed shovel. Push
the shovel into the ground as deep as you can and push it forward. Drop a half
cup of this fertilizer in the slit made by the shovel and close the slit with
your foot.

            If the
trees canopy is 10 foot in diameter, use two half cups of fertilizer, one on
each side of the tree, 2 feet from the trunk. If the trees canopy is 20 feet in
diameter, use six each, half cups of fertilizer, three on each side and spaced
about 2 feet apart. If the trees spread is 40 feet in diameter, apply 24 of
these half cups in wet soil under the canopy. Turn on the irrigation water in a
normal irrigation cycle, let it dissolve the fertilizer in the soil and carry
it to the roots.