In general, conifers are poor soil trees - that is to say, they choose and
thrive best in soils of low fertility and good drainage (meaning, in some
cases, sandy or gravelly soil). So they are not likely to be sucking all the
nutrients away in your garden .However, they probably are shading a good
part of your garden, and they are probably sucking water all around their
drip line. Also, some conifer needles are hostile to new plantings - things
like arborvitae drop little bitty needles that inhibit new growth on other
plants. If that is the case, you need to do a good job raking under the
conifers that hang over your yard and hauling off the needles.
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