From the plant’s “point of view”,
sunniness is determined by the length of
time that sun is shining directly on the
plant. The following are generally accepted
guidelines for determining the light conditions
of your garden:
FULL SUN is defined as more than 6 hours of sun
FULL SHADE is 0 to 2 hours of sun
PART SUN means 4 to 6 hours of sun and
PART SHADE is only 2 to 4 hours of sun.
(DAPPLED SHADE, that is the light that filters through the airy foliage of a honeylocust tree or an arbor, is very difficult to characterize. You will probably need to make your best guess and then observe the plant to see if it is located properly.)
You can determine the light levels of your garden by observing the actual hours of sun a particular spot receives. Note the time that the area starts receiving full sun, and then note when the shadows come back. It is important to do this during the prime growing season, in June, July and August. You will get very different results, which are not applicable to your garden, in winter when the sun is much lower and its arc covers less of the hemisphere. Other factors interact with the amount of sun to determine if the plant is in the right spot—soil moisture levels, reflected light from pavement or walls, or exposure to wind.
You may need to experiment by placing plants where you think they will do best, then observe them and be prepared to move them if they look “unhappy”. Plants that need more sun will get tall and leggy and lean toward the light until they fall over. Plants that need less sun will get browned leaf edges or even turn completely brown.
© Andrea Green 2005
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