Minnesota & Seasons

What “full sun” really means

Every plant tag makes it sound simple: full sun, part sun, shade. Then you get home to a real yard, with a garage shadow that swings like a clock hand and a maple that didn’t exist when the neighbors planted theirs. The tag words have exact meanings — the trick is knowing what your yard actually delivers.

The definitions, in hours of direct sun

Full sun is six or more hours of direct, unfiltered sun a day — they don’t have to be consecutive. Part sun is four to six. Part shade is also four-ish hours, but with the plant sheltered from the hot afternoon stretch. Shade is under three, or bright dappled light all day. The afternoon distinction matters more than people think: two hours of 4 pm western sun is a hotter, harsher dose than two hours at 9 am, and “part shade” plants that fry on a west wall will cruise on an east one.

Map it in one Saturday

Pick a clear day in the season you’re planting for. Set an alarm for the top of every hour from 8 am to 7 pm, and each hour take one photo of the garden area from the same spot. That evening, flip through and count: how many photos show direct sun on the actual soil, not just brightness nearby? That count is your number, and it turns every plant tag from a vibe into a spec.

Two north metro traps. First, June exaggerates — with 15½ hours of daylight at the solstice, almost everything qualifies briefly; a map made in mid-May or late July is more honest about the season as a whole. Second, trees lie in April. A yard mapped before the maples leaf out can lose three real hours by Memorial Day. Map after leaf-out, or mentally subtract.

Then match plants to the number

This is exactly what the Plant Picker is for: set the light to what your map measured — not what you wish it were — and every plant it shows will actually perform. Six-plus hours opens the whole sun catalog. Four honest hours of morning light is prime part-shade territory, which is a lush place to garden, not a consolation prize.